The focus of this thesis was to use active noise control (ANC) to globally minimize the tonal and broadband noise radiating from a diesel generator enclosure. The major goal of this research was to show that minimizing the noise within the enclosure can lead to an overall sound pressure level (SPL) reduction of radiated noise. The target levels for overall SPL reduction were at least 2 dBA. The control algorithms used in this research were based on a filtered-x LMS adaptive algorithm, which minimizes energy density (ED). Both feedforward and feedback control approaches were investigated. The noise spectrum produced by the diesel generator enclosure includes tonal and broadband components. The target range for control was from 0 to 300 Hz. Tonal frequencies at exterior locations were often reduced by 20 to 30 dB using feedforward control. With feedback control, tones were reduced 5 to 10 dB. Broadband control results were obtained at an exterior location using a feedforward control configuration. This control was achieved for frequencies between 100 and 600 Hz and levels were reduced by up to 5 dB. Some broadband control was achieved using feedback control, but this was limited to regions at the error sensor. An overall SPL reduction of 1.9 dBA outside the enclosure was achieved near the power terminal side of the enclosure. This was accomplished using tonal and broadband feedforward control. Experimental results show that control source placement, as well as error and reference sensor location, is key to global noise reduction.

The aim of the study was to investigate the knowledge and utilisation of antenatal care (ANC) services by pregnant women at a clinic in Ekurhuleni. A quantitative, descriptive correlational study was carried out on 90 eligible pregnant women. Data were collected with a self-administered questionnaire and analysed with the help of a statistician using the Epi Info version 7 computer program. The results of the study indicate that most women initiated ANC later than the recommendations by the World Health Organization (WHO). Over half of the respondents had overall good knowledge of ANC, but lacked knowledge of medication and screening tests done during pregnancy, some danger signs during pregnancy and of exclusive breastfeeding. Factors that were identified as associated with late initiation of ANC were current employment status, number of children, transport costs to clinic and number of antenatal visits. / Department of Health Studies / M.A. (Public Health)

The aim of the study was to investigate the knowledge and utilisation of antenatal care (ANC) services by pregnant women at a clinic in Ekurhuleni. A quantitative, descriptive correlational study was carried out on 90 eligible pregnant women. Data were collected with a self-administered questionnaire and analysed with the help of a statistician using the Epi Info version 7 computer program. The results of the study indicate that most women initiated ANC later than the recommendations by the World Health Organization (WHO). Over half of the respondents had overall good knowledge of ANC, but lacked knowledge of medication and screening tests done during pregnancy, some danger signs during pregnancy and of exclusive breastfeeding. Factors that were identified as associated with late initiation of ANC were current employment status, number of children, transport costs to clinic and number of antenatal visits. / Department of Health Studies / M.A. (Public Health)

Cette thèse a été effectuée dans le cadre du projet ANCRES. Son rôle est d'assurer la compréhension physique du milieu récepteur, le sol, alors qu'une autre équipe étudie l'impact physico-chimique des eaux usées traitées sur le sol. Pour cela, il faut connaître ses propriétés texturales et structurales contrôlant ses fonctions d'épuration et d'évacuation. La problématique est donc de comprendre le processus de l'infiltration imposée par un dispositif d'ANC dans un sol caillouteux. D'abord, suite au positionnement du site pilote d'ANC au pied d'un versant au cœur du plateau portlandien dans le département de l'Yonne en France, on a identifié là un type de sol hétérogène et complexe, caillouteux, une colluvion qui n'était pas cartographiée sur la carte géologique BRGM de cette région et sur laquelle on focalise la thèse. Ensuite, dans le sol complexe du site pilote, on a d'abord mesuré la conductivité hydraulique du sol par l'appareil Guelph sur 15 m² de la fouille de l'ANC à une profondeur de 120 cm : au total, on a fait 15 essais d'infiltration. De plus, on a récupéré 15 échantillons du sol accompagnant ses essais de Guelph pour la caractérisation physique au laboratoire. On a mesuré la texture, l'humidité résiduelle (HR), la teneur en cailloux (Rw) et la matière organique (MO) des échantillons au laboratoire. Ensuite, pour l'étude du processus d'infiltration, on a instrumenté ce site par un dispositif de surveillance hydrique (tensiométrie, teneur en eau, piézométrie) et de prélèvement d'eau interstitielle du sol. De plus, la masse volumique (densité) apparente d'un sol hétérogène a été déterminée. Parmi les paramètres mesurés, certains sont choisis comme indicateurs pour caractériser un sol comme milieu récepteur potentiel des eaux usées traitées en ANC. Puis, en utilisant la MO et la texture des échantillons, on a estimé la masse volumique apparente de la matrice du sol du site piloteau moyen de fonctions de pédotransfert appelées BD-FPTs et on a testé la relation entre la conductivité hydraulique à saturation Ks et la texture de ce sol complexe. Pour cela, une méthodologie en quatre phases a été développée pour évaluer la capacité prédictive des fonctions Ks-FPTs. Cette méthodologie de sélection n'a pas été trouvée dans la littérature mais est élaborée pour les besoins de la thèse. On a déduit les meilleures Ks-FPTs pour ce type de sol. Enfin, avec les données d'humidité volumique et du potentiel matriciel du sol, acquises par une centrale d'acquisition des données, le régime hydrodynamique du sol sous le massif filtrant de l'ANC a été étudié et on a mis en évidence l'écoulement préférentiel dans un sol caillouteux. Les résultats ont montré que dans la colluvion, bien que la matrice du sol soit fine, la conductivité hydraulique mesurée est plus élevée qu'attendu. Cela démontre que la fraction des cailloux dans le sol joue un rôle essentiel en accélérant l'évacuation des eaux usées traitées et aussi l'eau pluviale vers les couches sous-jacentes, et finalement vers la nappe. Cette propriété serait un point fort pour la fonction de transfert du sol et on peut en déduire une méthode pour améliorer la capacité de transfert de l'eau des sols lourds dans les projets d'aménagement urbain ou périurbain : l'ajout de graviers et graves calcaires par mélange au sol en place. On conclut que cette expérimentation, unique en son genre, a été utile pour évaluer la fonction de rétention / transfert de l'eau dans le sol recevant les eaux usées traitées. On a identifié les paramètres prédicteurs pertinents et les relations empiriques qui permettent de faire l'économie de nombreux essais in situ d'eau

Dans ce travail, on utilise la question raciale comme un prisme pour étudier le parti politique African National Congress (ANC), en se focalisant sur trois problèmes de recherche : la production de discours, la régulation et le changement partisan. Notre postulat de départ est que le positionnement idéologique nationaliste de l'ANC est un positionnement ambigu et pluriel, entre non-racialisme et nationalisme africain, entre caractère multi-classes et biais en faveur des pauvres et des travailleurs. C'est un consensus hétérogène sur ce positionnement multiple qui « tient » le parti ensemble. On entend tout d'abord démontrer que dans le contexte de la nouvelle Afrique du Sud démocratique et non-raciale, ce positionnement pluriel amène le parti à développer des discours alternatifs et à construire des identités collectives emboîtées, notamment dans son offre électorale. On étudie ensuite comment le nouvel environnement post-apartheid, celui d'une société normalisée où les clivages raciaux et socio-économiques évoluent, met en péril le consensus sur lequel repose l'ANC et émet des pressions sur le parti pour qu'il change et se repositionne. Enfin, on démontre qu'idéologie et organisation sont liées : du positionnement pluriel de l'ANC sur la question raciale découlent des règles formelles et informelles d'organisation et de fonctionnement.

<p>The first aim of this work has been to analyse and understand the ways in which a group of ANC-women politicians reason about bridewealth/<i>lobola</i> – an institution about which they express differing views, in particular about whether or not it is oppressive to women. The main body of the empirical material is based on 27 interviews conducted in South Africa in the period 1996-1998. </p><p>One finding of the study is that there are <i>explicit defining</i> discourses on <i>lobola </i>as well as more <i>implicitly </i>expressed understandings. The explicit discourses make a distinction between ’good <i>lobola</i>’ – which is expressed in a family-related discourse as ’a bond between families’ – and ’bad <i>lobola</i>’ which is expressed in, for instance, an economic discourse about ’the purchase of women’. The family-related discourse is interpreted as part of a discursive strategy to create <i>spaces for action</i> with respect to relations of gender-related power. (Re)definitions of <i>lobola</i> may be used not only to counter men’s abuse of monetary <i>lobola</i> but also to counter ’traditional’ gender meanings associated with <i>lobola</i>. Furthermore, explicit discourses on <i>lobola</i> are interpreted as a ‘political discourse’ which is formed both in relation to pragmatic ‘political realities’ but also in relation to hegemonic Western discourses. The political discourse on <i>lobola</i> in connection with ‘African identity’ constitutes a discursive strategy to provide <i>discursive space</i> in order for ’Africans’ to be able to (re)interpret a cherished but also controversial institution. </p><p>A second aim of the study has been of a self-reflexive character. It consitutes a critique of a ‘doing gender’ theoretical perspective as well as an attempt to transcend the ‘actor/structure dichotomy’ in sociological analysis. </p>

The first aim of this work has been to analyse and understand the ways in which a group of ANC-women politicians reason about bridewealth/lobola – an institution about which they express differing views, in particular about whether or not it is oppressive to women. The main body of the empirical material is based on 27 interviews conducted in South Africa in the period 1996-1998. One finding of the study is that there are explicit defining discourses on lobola as well as more implicitly expressed understandings. The explicit discourses make a distinction between ’good lobola’ – which is expressed in a family-related discourse as ’a bond between families’ – and ’bad lobola’ which is expressed in, for instance, an economic discourse about ’the purchase of women’. The family-related discourse is interpreted as part of a discursive strategy to create spaces for action with respect to relations of gender-related power. (Re)definitions of lobola may be used not only to counter men’s abuse of monetary lobola but also to counter ’traditional’ gender meanings associated with lobola. Furthermore, explicit discourses on lobola are interpreted as a ‘political discourse’ which is formed both in relation to pragmatic ‘political realities’ but also in relation to hegemonic Western discourses. The political discourse on lobola in connection with ‘African identity’ constitutes a discursive strategy to provide discursive space in order for ’Africans’ to be able to (re)interpret a cherished but also controversial institution. A second aim of the study has been of a self-reflexive character. It consitutes a critique of a ‘doing gender’ theoretical perspective as well as an attempt to transcend the ‘actor/structure dichotomy’ in sociological analysis.

In this thesis, I study the effects of the National School Nutrition Programme (NSNP) on the rural areas of Western Cape, South Africa. More precisely I try to find out how the NSNP has affected the families in this rural area and what attitudes that can be found among the two generations of people living and working on wine farms. The reason for this investigation is that NSNP was set up to increase school attendance among children living in an exposed socioeconomic environment, and I wanted to see how much the NSNP affect people’s daily life, with focus on the ones living on/near wine farms in the more rural areas in Western Cape since these areas holds socioeconomic groups that are exposed in the society.  To answer the research questions, I conducted several interviews with both wine farm workers and pupils living on/near a wine farm. But oral history is more than a method! I wanted to look upon the history from a grassroots perspective with a special focus on the working class, ethnic minorities and women´s part in the history.  My theory is based upon the terms Welfare and Social inequality. These two perspectives describe access to labor market, poverty, education and income support. These aspects highlight different forms of social exclusion which wine farm workers and pupils living on/near wine farm lives in.  With these methods I found out that the NSNP plays a crucial part in the lives of those who lives in the rural areas of Western Cape. Many pupils go to school just because their parents want it due to lack of food at home. The government’s purpose of the NSNP, to increase the school attendance can be seen in the answers giving to me during interviews with wine farm workers.

Windows are a weakness in building facade sound transmission loss (STL). This coupled with the detrimental effects of excessive noise exposure on human health including: annoyance, sleep deprivation, hearing impairment and heart disease, is the motivation for this investigation of the STL improvements active noise control (ANC) of windows can provide. Window speaker development, ANC window experiments and analytical modelling of ANC windows were investigated. Five different window speaker constructions were characterised then compared with a previously developed window speaker. ANC window testing used three different ANC configurations and was performed in two different environments, one with a reverberant receiving room, and the other with an anechoic receiving room. Optimisation of ANC systems with particular control source locations was the aim of the modelling. This enabled comparison with the ANC window tests and would aid in further development of ANC windows. Window speaker constructions were characterised by sound pressure level (SPL) measurements performed in an anechoic room. These measurements were made in a way that enabled comparison with the previously developed window speaker. Total sound energy reduction calculations were used to determine the relative performance of the tested ANC windows. An STL model, based on a modal panel vibration model, was initially created and verified against published STL data before it was expanded to include ANC control sources. The model was used to simulate the performed anechoic environment tests and an ideal ANC case.

The connection between phase shifts and the ANC has been explored in the frame of the effective range theory. The main result is that, in practice and under rather simple requirements, scattering states (phases shifts) can be correctly described and connected with bound states via the effective range function, and therefore, ANCs can be accurately determined thanks to the analytic properties of this function. This result has an important impact in stellar evolution due to the ANC and phases shifts are directly connected with capture cross sections which, for instance, determine partially the stage and evolution of stars.<p><p>As a first step, the effective range function is approximated via the effective range expansion which shows that a successful phase-shift description depends on how precise the effective range parameters are determined. Thus, a technique to compute accurately these parameters is developed here. Its construction is based on a set of recurrence relations at low energy, that allows a compact and general description of the truncated<p>effective range expansion. Several potential models are used to illustrate the effectiveness<p>of this technique and to discuss its numerical limitations. The results shows that a very good precision of the effective-range parameters can be achieved; nevertheless, to describe experimental phase shifts several effective-range parameters can be needed, which shows a limitation for practical applications.<p><p>As a second step, the effective range function is analyzed theoretically in an arbitrary energy range. This analysis shows that this function can be decomposed in such a way that contributions of bound states, resonances and background can be separated in a similar way as in the phenomenological R-matrix. In this new form experimental data can be better fitted because the free parameter space is reduced considerably,<p>and therefore, extrapolations are better handled. By construction, the method agrees with the scattering matrix properties which allows a simple calculation of resonances (locations and widths) and asymptotic normalization constants (ANCs). Several tests are successfully performed via potential models. Phase shifts for the 2 + partial wave of the 12C+α are analyzed with this method. They are correctly described including both<p>resonances at Ec.m. = 2.7 and 4.4 MeV. For the 6.92 MeV (2+) exited state of 16O, the ANC estimation 112(8) × 10 3 fm^−1/2 is obtained taking into account statistical errors. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished