L’aéroacoustique est une filière de l'acoustique qui étudie la génération de bruit par un mouvement fluidique turbulent ou par les forces aérodynamiques qui interagissent avec les surfaces. Ce secteur en pleine croissance a attiré des intérêts récents en raison de l’évolution de la transportation aérienne, terrestre et spatiale. Les microphones avec une bande passante de plusieurs centaines de kHz et une plage dynamique couvrant de 40Pa à 4 kPa sont nécessaires pour les mesures aéroacoustiques. Dans cette thèse, deux microphones MEMS de type piézorésistif à base de silicium polycristallin (poly-Si) latéralement cristallisé par l’induction métallique (MILC) sont conçus et fabriqués en utilisant respectivement les techniques de microfabrication de surface et de volume. Ces microphones sont calibrés à l'aide d'une source d’onde de choc (N-wave) générée par une étincelle électrique. Pour l'échantillon fabriqué par le micro-usinage de surface, la sensibilité statique mesurée est 0.4μV/V/Pa, la sensibilité dynamique est 0.033μV/V/Pa et la plage fréquentielle couvre à partir de 100 kHz avec une fréquence du premier mode de résonance à 400kHz. Pour l'échantillon fabriqué par le micro-usinage de volume, la sensibilité statique mesurée est 0.28μV/V/Pa, la sensibilité dynamique est 0.33μV/V/Pa et la plage fréquentielle couvre à partir de 6 kHz avec une fréquence du premier mode de résonance à 715kHz. / Aero-acoustics, a branch of acoustics which studies noise generation via either turbulent fluid motion or aerodynamic forces interacting with surfaces, is a growing area and has received fresh emphasis due to advances in air, ground and space transportation. Microphones with a bandwidth of several hundreds of kHz and a dynamic range covering 40Pa to 4kPa are needed for aero-acoustic measurements. In this thesis, two metal-induced-lateral-crystallized (MILC) polycrystalline silicon (poly-Si) based piezoresistive type MEMS microphones are designed and fabricated using surface micromachining and bulk micromachining techniques, respectively. These microphones are calibrated using an electrical spark generated shockwave (N-wave) source. For the surface micromachined sample, the measured static sensitivity is 0.4μV/V/Pa, dynamic sensitivity is 0.033μV/V/Pa and the frequency range starts from 100kHz with a first mode resonant frequency of 400kHz. For the bulk micromachined sample, the measured static sensitivity is 0.28μV/V/Pa, dynamic sensitivity is 0.33μV/V/Pa and the frequency range starts from 6kHz with a first mode resonant frequency of 715kHz.

Cette thèse traite le sujet du micro-actionnement multistable employant des radiations optiques pour atteindre les différentes positions offertes par le micro-actionneur. Dans le cadre des travaux réalisés, un mécanisme bistable reposant sur un principe de doubles poutres préformées situées en position antagoniste est proposé, et, sur cette brique élémentaire, un micro-actionneur quadristable a été conçu. Afin de valider le principe de fonctionnement de micro-actionneur, des procédés de fabrication Laser (sur le matériau « médium - MDF») puis DRIE (sur un wafer SOI de silicium) ont été utilisés. Sur le prototype en silicium, permettant une réduction des courses du rang interne et du rang externe du micro-actionneur, celles-ci ont été fixées à 300 µm et 200 µm respectivement. L’actionnement à distance de ce micro-actionneur a été prouvé en utilisant le chauffage laser d’un élément actif en Nitinol structuré par un dépôt de SiO2, ceci générant un effet « deux sens » de l’élément actif permettant d’annuler la charge sur les poutres du micro-actionneur une fois celui-ci déclenché puis en position stable. L’utilisation d’un banc expérimental incluant une membrane MEMS de balayage laser a permis de démontrer la quadristabilité du micro-actionneur sur 90 000 cycles. Afin de réduire davantage la course de ce micro-actionneur, des concepts de dispositifs de réduction de course ont été développés pour démontrer, à partir de prototypes fabriqué en MDF par usinage laser, la capacité à atteindre une course de 1 µm. Enfin, à la suite de ces travaux de réduction de course, un concept de nano-actionneur multistable a été proposé. Ce nano-actionneur est composé de quatre modules bistables liés et disposés en parallèle pour offrir 16 positions discrètes sur une course rectiligne. Les simulations de cet actionneur montrent la possibilité d’atteindre les 15 positions espacées de 10 nm sur une course de 150 nm. / In this work, a bistable mechanism based on antagonistic pre-shaped double beams was proposed. Employing the proposed bistable mechanism, a quadristable micro-actuator was designed. ln order to validate the quadristability of the device, a meso-scaled prototype was fabricated from MDF by laser cutting. After the quadristability was experimentally confirmed, a quadristable micro-actuator was realized on SOl wafer using DRIE technique. Strokes for inner row and outer row were reduced to 300 µm and 200 µm respectively. For the actuation of the quadristable micro-actuator,laser heated SMA elements with deposited Si02 layer were used to realize the optical wireless actuation. With the help of a laser beam steering micro-mirror, both inner row and outer row were successfully actuated. ln order to further reduce the stroke, a bistable actuator with stroke reducing structure was designed and a prototype eut from MDF was tested. Bistability was validated and a stroke of 1µm was experimentally achieved. Based on this bistable module, a multistable nano-actuator, which contains four parallel coupled bistable modules,was designed and simulated. The simulated result have indicated that it was capable of outputs 16 discrete stable positions available from 0 nm to 150 nm with a step of 10 nm between two stable positions.

In this dissertation a study was undertaken of the function of the public sector manager at the central level of government and of the role which the public manager plays in the human resources management. South Africa is a three-tier state, which consists of the central, provincial and local levels of government. The central government is the supreme body of government entrusted with the responsibility of making policies, rules and giving direction to the entire citizenry. The central government is manned by politicians from different political parties who have to decide on behalf of their electorates. It is a given fact and a reality that politicians alone cannot deliver the services to the communities. So public officials are appointed to implement the policies enacted by Parliament. Public managers have to interpret policies and give direction to the various structures of government. Among the activities of government, public managers have also to give direction as to the management of human resources in the public sector. This study investigated the function of the public manager at the central government with a reference to the management of human resources. This research was necessitated by the fact that since the new constitutional dispensation in South Africa, many changes have taken place most of which implied that the management of human resources in the public sector would have to reflect such changes. Public managers perform various functions, including generic administrative functions, auxiliary functions and functional activities. These functions are performed at senior management level. Furthermore, these functions performed by public managers will be viewed from the human resource management. Particular, attention is focused on the staffing in the public sector and how public managers can best perform their function in absorbing proper personnel in the public sector. AFRIKAANS : 'n Studie is onderneem om die funksie van die openbare sektor bestuurder op sentrale regeringsvlak te ondersoek asook die rol wat die openbare bestuurder speel in menslike hulpbronbestuur. Die verantwoordelikheid van die openbare sektor is om dienste te verskaf aan die landsburgers en om dit suksesvol te bereik meet die openbare sektor oor goed opgeleide personeel beskik. Ten einde personeel te kan bestuur behoort openbare bestuurders kennis te dra van die behoeftes, vrese en verwagtinge van die publiek. Een van die vernaamste funksies van die openbare bestuurder is om leiding te gee aan andere. Suid Afrika is 'n driedelige staat, wat bestaan uit die sentrale, provinsiale en plaaslike vlakke van regering. Die sentrale regering is die hoogste regeringsliggaam verantwoordelik vir beleidmaking, die daarsteling van reëls en om rigting te gee aan alle landsburgers. Die sentrale regering word gevorm deur politici van verskillende politieke partye wat namens hul ondersteuners besluite moet neem. Dit is 'n onomstootlike feit en werklikheid dat politici nie alleen die dienste aan die gemeenskap kan verskaf nie. Daarom word openbare amptenare aangestel om die beleid wat deur die Parlement aanvaar is, te implementeer. Openbare bestuurders moet beleid interpreteer en leiding gee binne die verskillende strukture van die regering. Die aktiwiteite van die regering bring mee dat openbare bestuurders leiding moet gee rakende die bestuur van menslike hulpbronne in die openbare sektor. Hierdie studie het die funksie van die openbare bestuurder in die sentrale regering ondersoek met verwysing na die bestuur van menslike hulpbronne. Die navorsing was genoodsaak deur die feit dat sedert die nuwe grondwetlike bedeling in Suid Afrika baie veranderinge plaasgevind het waarvan meeste impliseer dat die bestuur van menslike hulpbronne in die openbare sektor sodanige veranderinge sal reflekteer. Openbare bestuurders voer verskeie funksies uit insluitende generiese administratiewe funksies, hulpfunksies en funksionele aktiwiteite. Hierdie funksies word op senior bestuursvlak uitgevoer. Verder word hierdie funksies wat deur openbare bestuurders uitgevoer word beskou vanuit 'n menslike hulpbron oogpunt. Spesifieke aandag is gegee aan die personeel in die openbare sektor en hoe openbare bestuurders hulle funksies tot die beste van hul vermoë kan uitvoer deur bekwame personeel in diens te neem in die openbare sektor. Die studie toon aan dat daar tydens die transformasie van die Suid-Afrikaanse staatdiens politieke oorweging geskenk sal moet word aan die vervanging van wit persone met swartes, vrouens en gestremdes. In partypolitieke terme beteken dit geensins 'n balans tussen diegene wat die waardes van die ou orde aanhang en diegene wat die waardes van die nuwe orde bevorder nie. Die Grondwet van die Republiek van Suid-Afrika, 1996 volg 'n humanistiese benadering, wat beteken dat die armes, werkloses, verwaarloosde en wanhopige mense gehelp moet word wat in sigself nie 'n partypolitieke kwessie is nie. Verder toon internasionale onderving dat die radikale transformasie van grondwette dikwels vrees, onsekerheid en paniek onder inwoners veroorsaak. Hierdie gevoelens word dikwels op verskillende wyses deur verskillende gemeenskappe tot uiting gebring. S.A. is daarom geen uitsondering nie. Die vermoë van die staatsdiens om dienste te lewer sal nie net afhang van die politieke leierskap en bestuursvaardighede van die politieke ampsbekleders nie, maar ook van die professionalisme van staatsamptenare. Copyright / Dissertation (MAdmin)--University of Pretoria, 2012. / School of Public Management and Administration (SPMA) / Unrestricted

Measurement of absorption spectra of plasma during reactive ion etching enables characterization of etched species and control over the etching process. Aim of this diploma thesis is to design spectroscope with Czerny-Turner configuration for reactive ion etching system. Developed spectroscope achieves 1 nm resolution in 350-800 nm range. Device was tested during reactive ion etching of silicon.

Ministers have a very unique occupation with designated job demands and incongruous resources at their disposal. Over the past few years numerous studies have been undertaken different occupations’ regarding job demands and job resources. In contrast, limited studies were done among ministers of religion, particularly in the context of the three Reformed sister churches in South Africa. This is the case even though these ministers play such a key role in the current social and religious sphere. Results from previous studies have shown that job demands and the lack of resources have a major impact on the experience of work-nonwork interference among individuals (Koekemoer & Mostert, 2006; Mostert, 2009, Mostert & Oosthuizen, 2006; Tshabalala, 2007; Van Aarde & Mostert, 2008).This trend, however, has not been researched amongst ministers before – particularly how ministers cope with this interference. The overall objective of the present study was to investigate job demands and job resources as significant predictors of work-nonwork interference for ministers of the three sister churches. The focus also was on coping strategies that are significant in dealing with work-nonwork interference. The possible moderation brought about by these coping strategies was also investigated. Various hypotheses related to the overall objective were tested in the empirical study. The design used for this study was a cross-sectional survey design undertaken among ministers of the three sister churches mentioned. Various job demands, job resources, worknonwork interference and coping strategies were measured. This was done by employing the instruments of Peeters, Montgomery, Bakker and Schaufeli, (2005); Buys and Rothmann (2009); Koekemoer, Mostert and Rothman, 2010; Geurts et al. (2005) and Carver, Scheier and Weintraub (1989). Construct validity of all the instruments were proven with the CFA (Confirmatory Factor Analysis) in the SPSS program. Descriptive statistics, cronbach alpha coefficients, Pearson and Spearman product-moment correlations and multiple regression analyses were used to analyse the data. Moderation regression analyses were also done to test for possible moderation of specific coping strategies. Results indicated that cognitive demands were related to the dimension of work-parent interference. Emotional demands and pace and amount of work had a relation with all the various dimensions of the work-nonwork interference. Congregational support related work-home interference as well as work-religion/spirituality interference. Financial support, lack of autonomy, as well as social support, related to all three dimensions of work-nonwork interference. Job significance related work-religion/spirituality interference, whereas job accomplishment predicted work-home interference and work-religion/spirituality interference. The results of the predictors on work-parent interference included the following: cognitive demands, pace and amount of work, financial support and turning-to-religion. Work-home interference was predicted by the variables pace and amount of work and financial support. Work-religion/spirituality interference were predicted by pace and amount of work, job significance and turning to religion. The various coping strategies (turning-to-religion, seeking-emotional-support, active coping, acceptance coping, planning and avoidance coping) functioned as moderators between certain specific job demands, job resources and dimensions of work-nonwork interference. Limitations of the study were discussed and recommendations were put forward for future studies on this topic. / MCom (Industrial Psychology), North-West University, Potchefstroom Campus, 2014

Ministers have a very unique occupation with designated job demands and incongruous resources at their disposal. Over the past few years numerous studies have been undertaken different occupations’ regarding job demands and job resources. In contrast, limited studies were done among ministers of religion, particularly in the context of the three Reformed sister churches in South Africa. This is the case even though these ministers play such a key role in the current social and religious sphere. Results from previous studies have shown that job demands and the lack of resources have a major impact on the experience of work-nonwork interference among individuals (Koekemoer & Mostert, 2006; Mostert, 2009, Mostert & Oosthuizen, 2006; Tshabalala, 2007; Van Aarde & Mostert, 2008).This trend, however, has not been researched amongst ministers before – particularly how ministers cope with this interference. The overall objective of the present study was to investigate job demands and job resources as significant predictors of work-nonwork interference for ministers of the three sister churches. The focus also was on coping strategies that are significant in dealing with work-nonwork interference. The possible moderation brought about by these coping strategies was also investigated. Various hypotheses related to the overall objective were tested in the empirical study. The design used for this study was a cross-sectional survey design undertaken among ministers of the three sister churches mentioned. Various job demands, job resources, worknonwork interference and coping strategies were measured. This was done by employing the instruments of Peeters, Montgomery, Bakker and Schaufeli, (2005); Buys and Rothmann (2009); Koekemoer, Mostert and Rothman, 2010; Geurts et al. (2005) and Carver, Scheier and Weintraub (1989). Construct validity of all the instruments were proven with the CFA (Confirmatory Factor Analysis) in the SPSS program. Descriptive statistics, cronbach alpha coefficients, Pearson and Spearman product-moment correlations and multiple regression analyses were used to analyse the data. Moderation regression analyses were also done to test for possible moderation of specific coping strategies. Results indicated that cognitive demands were related to the dimension of work-parent interference. Emotional demands and pace and amount of work had a relation with all the various dimensions of the work-nonwork interference. Congregational support related work-home interference as well as work-religion/spirituality interference. Financial support, lack of autonomy, as well as social support, related to all three dimensions of work-nonwork interference. Job significance related work-religion/spirituality interference, whereas job accomplishment predicted work-home interference and work-religion/spirituality interference. The results of the predictors on work-parent interference included the following: cognitive demands, pace and amount of work, financial support and turning-to-religion. Work-home interference was predicted by the variables pace and amount of work and financial support. Work-religion/spirituality interference were predicted by pace and amount of work, job significance and turning to religion. The various coping strategies (turning-to-religion, seeking-emotional-support, active coping, acceptance coping, planning and avoidance coping) functioned as moderators between certain specific job demands, job resources and dimensions of work-nonwork interference. Limitations of the study were discussed and recommendations were put forward for future studies on this topic. / MCom (Industrial Psychology), North-West University, Potchefstroom Campus, 2014

Text in Afrikaans / The concepts of parody and pastiche are oftell employed by leading theoreticians to offer definitions of the elusive term "Postmodernism". One is led to conclude that parody and pastiche are direct1y linked to Postmodernism. This is especially valid in the case of pastiche. Indeed, it appears, therefore, that the continllous assumption of the appellation "pastiche" in the Postmodernist discourse could reveal its link to Postmodernism and Postmodernity in general. While parody and pastiche are not new phenomena, the question is why, ill our time, these concepts should be so acutely present in the discourse of literary theory - especially in theoretic contributions on Postmodernism and/or Postmodernis! texts. However, an investigation of the studies done on Postmodernist drama/theatre reveals a distinct lack of reflection about the role of parody and pastiche and a disturbing absence of publication on the the subject. This state of affairs reveals a conspicuous delay in terms of theoretical deliberation when compared to other investigat1ve practices, i.e. literary criticism and philosophy. This study, then, is essentially interested in transposing the present emphasis on parody and pastiche found in contemporary literary theory to Postmodernist drama/theatre. The final objective of this study is to explore the impact of the concepts of parody and pastiche on twentieth century drama/theatre and their possible contribution to a better understanding of the elusive term "Postmodemist drama/theatre". / Afrikaans and Theory of Literature / D. Litt. et Phil. (Literature)

Three ionic liquids (ILs), trihexyltetradecylphosphonium tetrafluoroborate (TTPT), N-butyl-4-methylpyridinium tetrafluoroborate (BMPT), and 1-methyl-3- octylimidazolium tetrafluoroborate (MOIC), were utilized to prepare sol- gel sorbent coatings. Non-polar polydimethylsiloxane (PDMS) and polar poly(ethylene glycol) (PEG), poly(tetrahydrofuran) (PolyTHF) and bis[(3-methyldimethoxy-silyl)propyl] polypropylene oxide (BMPO) polymers were employed to develop novel ionic liquidmediated sol- gel hybrid organic- inorganic sorbents. The novel sorbents were first tested as coatings for capillary microextraction off-line hyphenated to gas chromatography. To gain an understanding of the role of the ionic liquids in the sol-gel process, the preconcentration abilities of these novel coatings were investigated for several classes of compounds utilizing CME-GC. This was accomplished by comparing GC peak areas of a series of analytes extracted on the ionic liquid mediated sol-gel CME coatings with that of analogous peak areas obtained on sol- gel coatings prepared without the ionic liquid. The morphology of these coatings was compared using scanning electron microscopy (SEM) imaging data. Overall, the ionic liquid-mediated sol- gel coatings had more porous morphologies than the sol-gel coatings prepared without ionic liquid. The PDMS andBMPO sol-gel coatings prepared with ionic liquid in the sol solution provided enhanced extraction sensitivity reflected in higher preconcentration effects and lower detection limits than the sol- gel coatings prepared without the ionic liquid. The polar IL-mediated BMPO sol- gel sorbent was further investigated by exploring the extraction profile and thermal stability of these coatings. A further application of ionic liquid-mediated sol-gel sorbents could be as stationary phases in a microchip-based separation system. Towards this goal, microfluidic channels were fabricated in glass substrates using microelectromechanical engineering. Spiral and serpentine channels were etched in Pyrex and fused silica wafers using wet and deep reactive ion etching (DRIE) techniques. Microfabrication protocols such as the use of hard mask and etching times were investigated for both techniques. DRIE produced microfluidic channels that had an etch quality that was superior to wet etched channels. Thus, the ultimate microchip-based separation system should by fabricated using DRIE.

L'imagerie multispectrale permet d'améliorer la détection et la reconnaissance de cibles dans les applications de surveillance. Elle consiste à analyser des images de la même scène acquises simultanément dans plusieurs bandes spectrales grâce à un filtrage. Cette thèse étudie la possibilité de réaliser une matrice de 4 filtres Fabry Pérot (FP) intégrés 3D et ajustables par actionnement électrostatique dans le domaine visible-proche infrarouge. Les miroirs fixes des filtres FP sont des multicouches ZnS/YF₃ déposés sur un wafer de borosilicate, et les miroirs mobiles sont des membranes multicouches PECVD SiNH/SiOH encastrées sur une structure mobile très compacte micro-usinée dans un wafer en silicium. Les performances optiques des filtres FP ont été optimisées en prenant en compte la dissymétrie et le déphasage à la réflexion des miroirs. La structure mobile a été modélisée par éléments finis pour minimiser ses déformations lors de l'actionnement. Les étapes critiques des procédés de fabrication des miroirs mobiles en technologie Si ou SOI ont été mises au point : i) la fabrication et la libération par gravures profondes DRIE et XeF₂ des membranes multicouches avec une contrainte résiduelle ajustée par recuit et une réflectance voisine de 50% dans une large gamme spectrale, ii) le contrôle des vitesse de la gravure DRIE avec des motifs temporaires permettant la gravure simultanée de motifs de largeur et de profondeur variables, et iii) la délimitation de motifs sur surfaces fortement structurées à l'aide de pochoirs alignés mécaniquement ou de films secs photosensibles. Ces travaux ouvrent la voie vers une réalisation complète d'une matrice de filtres FP intégrés 3D.

Text in Afrikaans / The concepts of parody and pastiche are oftell employed by leading theoreticians to offer definitions of the elusive term "Postmodernism". One is led to conclude that parody and pastiche are direct1y linked to Postmodernism. This is especially valid in the case of pastiche. Indeed, it appears, therefore, that the continllous assumption of the appellation "pastiche" in the Postmodernist discourse could reveal its link to Postmodernism and Postmodernity in general. While parody and pastiche are not new phenomena, the question is why, ill our time, these concepts should be so acutely present in the discourse of literary theory - especially in theoretic contributions on Postmodernism and/or Postmodernis! texts. However, an investigation of the studies done on Postmodernist drama/theatre reveals a distinct lack of reflection about the role of parody and pastiche and a disturbing absence of publication on the the subject. This state of affairs reveals a conspicuous delay in terms of theoretical deliberation when compared to other investigat1ve practices, i.e. literary criticism and philosophy. This study, then, is essentially interested in transposing the present emphasis on parody and pastiche found in contemporary literary theory to Postmodernist drama/theatre. The final objective of this study is to explore the impact of the concepts of parody and pastiche on twentieth century drama/theatre and their possible contribution to a better understanding of the elusive term "Postmodemist drama/theatre". / Afrikaans and Theory of Literature / D. Litt. et Phil. (Literature)