The introduction of inverters utilizing wide band-gap semiconductors allow for higher switching frequency and improved machine drive energy efficiency. However, inverter switching results in fast voltage surges which cause overvoltage at the stator terminals and uneven voltage distribution in the stator winding. Therefore, it is important to understand how next generation machine drives, with higher switching frequency, affect the voltage distribution. For this purpose, a lumped-parameter model capable of simulating winding interturn voltages for the wide frequency range of 0-10 MHz is developed for a slotless PMSM. The model includes both capacitive and inductive couplings, extracted from 2D finite element simulations, as well as analytically estimated resistive winding losses. The developed model of a single phase-winding is used to investigate how machine design aspects such as insulation materials and winding conductor distribution affects both voltage distribution and winding impedance spectrum. Validation measurements demonstrate that the model is accurate for the wide frequency range. The sensitivity analysis suggests that the winding conductor distribution affect both impedance spectrum and voltage distribution. For the slotless machine, capacitance between the winding and the stator is several times smaller than capacitance between turns. Therefore, the high-frequency effects are dominated by the capacitance between turns. Insulation materials that affect this coupling does therefore have an impact on the impedance spectrum but does not have any significant impact on the voltage distribution. / Nästa generations inverterare för styrning av elektriska maskiner, baserade på bredbandgaps komponenter, tillåter högre switchfrekvenser vilket skapar en energieffektivare drivlina. Nackdelen är att snabba spänningsflanker från den höga switchfrekvensen skapar överspänning på stators anslutningar och en ojämn spänningsfördelning i statorlindningen. Det är därför betydelsefullt att förstå hur dessa nya drivlinor påverkar lindningens spänningsfördelning. I denna rapport används en modell kapabel att simulera lindningens spänningsfördelning i det breda frekvensspektrumet 0-10 MHZ. Modellen är framtagen för en faslindning av en PMSM, utan statoröppning, som inkluderar både kapacitiva och induktiva kopplingar samt analytiskt beräknade lindningsförluster. Modellen används för att undersöka spänningsfördelningen i lindningen samt inverkan från designparametrar som isolationsmaterial och lindningsdistribution. Känslighetsanalysen visar att lindingsdistributionen har en signifikant påverkan på både impedansspektrumet och spänningsfördelningen. För den studerade maskintypen är det kapacitansen mellan varv som är dominerande för högfrekventa fenomen. Isolationsmaterial som påverkar denna koppling har en påverkan på impedansspektrumet men är liten för spänningsfördelningen.

Cette thèse s’inscrit dans le cadre de l’amélioration du comportement électrique des isolateurs de lignes haute tension ; l’objectif est d’assurer une meilleure fiabilité et qualité d’alimentation en énergie électrique. Ce travail a été motivé par la nécessité de répondre à trois questions liées au comportement des isolateurs verre en zone polluée. La première porte sur la recherche d’une méthode permettant de calculer la tension de contournement des chaînes polluées selon le type d’isolateur et ses caractéristiques. La deuxième question concerne la différence de comportement entre les isolateurs en verre et les isolateurs en porcelaine de type « outerrib » ; ce type d’isolateurs présente une forme spécifique adaptée aux environnements à forte pollution. Les tensions de contournement ainsi que les trajectoires de l’arc sur les isolateurs en verre sont très différentes de celles observées avec les isolateurs en porcelaine. Et la troisième question est relative à la défaillance des isolateurs recouverts de silicone lors des essais en chocs (des impulsions de tension) à front raide. En effet, les isolateurs recouverts d’une couche de 0.3 mm (ou plus) de silicone hydrophobe explosent lorsqu’ils sont soumis à des impulsions de tension à front raide d’amplitude très élevée pendant un temps très court. Différents mécanismes pouvant être à l’origine de l’explosion/éclatement des isolateurs recouverts d’une couche de silicone sont discutés. Il ressort des différents tests et analyses que le mécanisme le plus probable semble être la fragmentation par plasma. En effet, suite à l’application d’une tension à front raide, d’amplitude très élevée, des canaux (fissures) microscopiques prennent naissance là où le champ électrique est le plus intense. L’application répétitive des chocs de tension conduit au développement de décharges dans ces canaux (rupture diélectrique de l’air) c’est-à-dire des arcs (canaux de plasma) qui se développent/propagent dans le volume de l’isolateur. La puissance déchargée (c’est-à-dire l’énergie stockée dans les condensateurs du générateur en des temps très courts) dans ces canaux à chaque choc étant très élevée, elle conduit à l’explosion de l’isolateur après quelques chocs (parfois 5 ou 6 suffisent): c’est la fragmentation par plasma. / This thesis deals with the improvement of the electrical behavior of insulators of high voltage lines; the objective is to ensure better reliability and quality of power supply. This work was motivated by the need to answer three questions related to the behavior of glass insulators in polluted areas. The first one concerns the search for method for calculating the flashover voltage of polluted chains according to the type of insulator and its characteristics. The second question concerns the difference in behavior between glass insulators and "outerrib" porcelain insulators; this type of insulator has a specific shape adapted to environments with high pollution. The flashover voltages as well as the trajectories of the arc on glass insulators are very different from those observed with porcelain insulators. And the third issue is the failure of silicon-coated insulators during shock tests (pulses) with a steep front. Indeed, insulators coated with a layer of 0.3 mm (or more) of hydrophobic silicone explode when subjected to very high amplitude steep-edge voltage pulses for a very short time. Different mechanisms that may be responsible for the explosion / puncturing of insulators covered with a layer of silicone are discussed. It appears from the various tests and analyzes that the most probable mechanism seems to be plasma fragmentation (cracking). Indeed, following the application of a steep front voltage, of very high amplitude, microscopic channels (fissures) originate where the electric field is most intense. The repetitive application of impulse voltages (shocks) leads to the development of discharges in these channels (breakdown of the air), i.e.; arcs (plasma channels) which develop / propagate in the volume of the insulator. The discharged power (i.e.; the energy stored in the capacitors of the generator in a very short times) in these channels (cracks) at each shock being very high, leads to the explosion of the insulator after some shocks (5 to 6 sometimes): it is the fragmentation by plasma or plasma cracking.

Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Consumer Science: Food and Nutrition in the Faculty of Applied Sciences at the Cape Peninsula University of Technology 2012 / The chronic diseases of lifestyle, tuberculosis and Human immunodeficiency virus/Acquired immunodeficiency syndrome have a high prevalence in South Africa. These diseases are characterised by oxidative stress and a chronic inflammatory state that contribute to both the development and the acceleration of these diseases. Research into the phytochemical plant food components suggest that these substances could possibly play a vital role in the prevention of such disease. Corn steep liquor (CSL) is a waste product with an exceptionally high polyphenol content and total antioxidant capacity (TAC). This led to the suggestion that it could be utilised in the development of food products with functional food characteristics. Stock cubes, due to the widespread use among consumers of different socio-economic backgrounds, were identified as vehicle for the delivery of the CSL with its phytochemical content. This lead to the development of a stock cube utilising CSL as a source of phytochemical polyphenolic antioxidants with the micronutrients zinc, selenium and copper as added support to immunonutrition, along with iron due to the wide spread prevalence of iron deficiency in the South African population. The acceptability of the developed stock cube was tested by preparing savoury rice and pea soup and having blue collar (n = 50) and white collar (n = 49) participants rate the acceptability on a 9-point hedonic scale, ranging from “dislike extremely” to “like extremely”. The savoury rice received a 41% “like very much” rating followed by a 24% “like moderately” rating. The pea soup was rated even more positively as it received a 42% “like very much” rating and a 29% “like extremely” rating. In addition, among the blue collar participants, significant (p < 0.05 for each) findings occurred with a greater liking of the sample dishes prepared with the developed stock cube by participants of the ethnic Black grouping, with Xhosa as home language and being married, as well as those participants who habitually prepare the meals in the household. A significant (p < 0.05) finding with the white collar participants was a greater liking of the sample dishes prepared with the developed stock cube among those participants who would be willing to make use of a stock cube with health benefits. The developed stock cube was also subjected to six months accelerated shelf-life stability testing, reflecting twelve months real time storage. The parameters measured were microbial growth, oxidative rancidity, antioxidant status and organoleptic changes. All microbial growths tested remained within the acceptable specification ranges. Oxidative rancidity, measured as the peroxide value, was detected analytically at the fifth and sixth samplings, but was not detectable organoleptically. The antioxidant status, measured as the TAC and the total polyphenol content, remained relatively stable during the testing period. Though no noticeable organoleptic changes were observed during the stability testing, there was a darkening of the colour by the second sampling. The results of the acceptance testing, as well as the shelf-life stability testing, support the conclusions that the study objectives of developing a stock cube with functional food characteristics and it being received positively by consumers were achieved. Keywords: stock cubes; corn steep liquor; phytochemicals; consumer acceptance; new product development

The EC Landfill Directive (1999), which is enforced in England and Wales through the Landfill (England and Wales) Regulations (2002), has increased the technical challenge associated with the design and construction of landfill containment systems, in particular those on steep side slopes. Increased numbers of lining system components, varied configurations, and complex loading scenarios require advanced analysis tools to facilitate design. This project involved the development of advanced numerical modelling techniques, based on the FLAC finite difference modelling code. The analysis toolbox can be used to predict the behaviour of multilayered geosynthetic and soil lining systems, during and after staged construction. The model can include non-linear interface and geosynthetic axial properties, represent complex loading, including downdrag from the waste mass, whilst retaining the flexibility to represent varied geometries and include engineered support structures. Whilst numerical modelling is becoming increasingly commonplace in commercial design, there is little evidence of the validation of numerical models with field or experimental data. Validation of the analysis toolbox described in this document was conducted by back analysis of published data, modelling of landfill failure mechanisms, and comparisons to large scale laboratory testing. Design of field scale instrumentation has also been carried out as part of this project. The influence of interface shear strength variability has been assessed through the compilation of a comprehensive database, and the effect of this variability on lining system behaviour assessed through reliability based analyses. This has shown probability of failures may be higher than proposed limiting values when adopting traditional accepted factors of safety. A key area of interest identified during the project was the requirement for support, potentially through reinforcement, of the geological barrier. The inclusion of randomly reinforced fibres in bentonite enhanced soil has shown the potential for increased strength, without adverse effects on hydraulic barrier performance. ii Additionally, the influence of geomembrane seams on lining system integrity has been investigated, showing that fusion welded seams can result in stress concentration and extruded seams can cause significant stress concentration.

Assuming that liquid iron alloy from the outer core interacts with the solid silicate-rich lower mantle the influence on the core-mantle reflected phase PcP is studied. If the core-mantle boundary is not a sharp discontinuity, this becomes apparent in the waveform and amplitude of PcP. Iron-silicate mixing would lead to regions of partial melting with higher density which in turn reduces the velocity of seismic waves. On the basis of the calculation and interpretation of short-period synthetic seismograms, using the reflectivity and Gauss Beam method, a model space is evaluated for these ultra-low velocity zones (ULVZs). The aim of this thesis is to analyse the behaviour of PcP between 10° and 40° source distance for such models using different velocity and density configurations. Furthermore, the resolution limits of seismic data are discussed. The influence of the assumed layer thickness, dominant source frequency and ULVZ topography are analysed. The Gräfenberg and NORSAR arrays are then used to investigate PcP from deep earthquakes and nuclear explosions. The seismic resolution of an ULVZ is limited both for velocity and density contrasts and layer thicknesses. Even a very thin global core-mantle transition zone (CMTZ), rather than a discrete boundary and also with strong impedance contrasts, seems possible: If no precursor is observable but the PcP_model /PcP_smooth amplitude reduction amounts to more than 10%, a very thin ULVZ of 5 km with a first-order discontinuity may exist. Otherwise, if amplitude reductions of less than 10% are obtained, this could indicate either a moderate, thin ULVZ or a gradient mantle-side CMTZ. Synthetic computations reveal notable amplitude variations as function of the distance and the impedance contrasts. Thereby a primary density effect in the very steep-angle range and a pronounced velocity dependency in the wide-angle region can be predicted. In view of the modelled findings, there is evidence for a 10 to 13.5 km thick ULVZ 600 km south-eastern of Moscow with a NW-SE extension of about 450 km. Here a single specific assumption about the velocity and density anomaly is not possible. This is in agreement with the synthetic results in which several models create similar amplitude-waveform characteristics. For example, a ULVZ model with contrasts of -5% VP / -15% VS and +5% density explain the measured PcP amplitudes. Moreover, below SW Finland and NNW of the Caspian Sea a CMB topography can be assumed. The amplitude measurements indicate a wavelength of 200 km and a height of 1 km topography, previously also shown in the study by Kampfmann and Müller (1989). Better constraints might be provided by a joined analysis of seismological data, mineralogical experiments and geodynamic modelling. / Unter der Annahme, dass flüssiges Eisen aus dem äußeren Erdkern mit dem festen, silikat-reichen Unteren Mantel reagiert, wird eine Einflussnahme auf die Kern-Mantel Reflexionsphase PcP erwartet. Ist die Kern-Mantel Grenze aufgeweicht, und nicht wie bislang angenommen ein diskreter Übergang, so zeichnet sich dies in der Wellenform und Amplitude von PcP ab. Die Interaktion mit Eisen führt zu teilweise aufgeschmolzenen Bereichen höherer Dichte, welche die seismischen Wellengeschwindigkeiten herabsetzen. Basierend auf den Berechnungen von kurzperiodischen synthetischen Seismogrammen, mittels der Reflektivitäts- und Gauss Beam Methode, soll ein möglicher Modellraum dieser Niedriggeschwindigkeitszonen ermittelt werden. Das Ziel dieser Arbeit ist es das Verhalten von PcP im Distanzbereich von 10° bis 40° unter dem Einfluss dieser Modelle mit diversen Geschwindigkeits- und Dichtekontrasten zu untersuchen. Ferner wird das Auflösungsvermögen hinsichtlich seismischer Daten diskutiert. Entscheidende Parameter wie Anomaliedicke, Quellfrequenz und Topographie werden hierbei analysiert. Tiefe Erdbeben und Kernexplosionen, die sich im entsprechenden Entfernungsbereich zum Gräfenberg und NORSAR Array befinden, werden anschließend im Hinblick auf PcP ausgewertet. Das seismische Auflösungsvermögen von Niedriggeschwindigkeitszonen ist stark begrenzt sowohl in Bezug auf Geschwindigkeits- und Dichtekontraste als auch hinsichtlich der Mächtigkeit. Es besteht sogar die Möglichkeit einer dünnen, globalen Kern-Mantel Übergangszone, selbst mit großen Impedanzkontrasten, ohne dass dies mit seismologischen Methoden detektiert werden könnte: Wird kein precursor zu PcP beobachtet aber das PcPmodel /PcPsmooth Amplitudenverhältnis zeigt gleichzeitig eine Reduktion von mehr als 10%, dann könnte eine sehr dünne Niedriggeschwindigkeitszone von ca. 5 km Mächtigkeit und einer Diskontinuität erster Ordnung vorliegen. Andererseits, ist PcP um weniger als 10% reduziert, könnte dies entweder auf eine dünne, moderate Niedriggeschwindigkeitszone oder einen graduellen Kern-Mantel Übergang hindeuten. Die synthetischen Berechnungen ergeben starke Amplitudenvariationen als Funktion der Distanz, welche auf den Impedanzkontrast zurückzuführen sind. Dabei ergibt sich ein primärer Dichteeffekt im extremen Steilwinkelbereich und ein maßgeblicher Geschwindigkeitseinfluss im Weitwinkelbereich. Im Hinblick auf die modellierten Resultate lässt sich eine 10 - 13.5 km mächtige Niedriggeschwindigkeitszone 600 km südöstlich von Moskau mit einer NW-SE Ausdehnung von mindestens 450 km folgern, wobei eine exakte Aussage über Geschwindigkeiten und Dichte nicht möglich ist. Dies ist im Konsens mit den synthetischen Berechnungen, wonach viele unterschiedliche Modelle ähnliche Amplituden- und Wellenformcharakteristiken erzeugen. Zum Beispiel erklärt ein Modell mit Kontrasten von -5% VP / -15% VS and +5% Dichte die gemessenen PcP Amplituden. Darüber hinaus können unterhalb des südwestlichen Finnlands und nord-nordwestlich des Kaspischen Meeres Undulationen an der Kern-Mantel Grenze selbst vermutet werden. Unter Berücksichtigung früherer Studien, z. B. von Kampfmann and Müller (1989), deuten die Messergebnisse auf eine laterale Topographie von 200 km und eine Höhe von 1 km hin. Eine Eingrenzung der potentiellen Anomaliemodelle kann nur durch eine gemeinsame Auswertung mit mineralogischen Experimenten und geodynamischen Modellierungen erfolgen.

The graduated thesis is described the characteristic of a permanent grass vegetations, analysis of the scale of production a pasturage in chosen establishment and identification with a technological line for harvest and conservation pasturage. Next describe size of a store, land steep a traffic distance. This thesis describes measuring procedure in order to location of engineering characteristics, consumption of fuels and financial evaluation of all operation in the end.

Les modèles d’habitat hydrauliques sont fréquemment utilisés pour prédire les impacts écologiques de la gestion des débits des rivières. Ils couplent des modèles hydrauliques des tronçons de rivières à des modèles de "préférences" des organismes pour les conditions hydrauliques de leur microhabitat (vitesses, hauteurs, forces). Les modèles d'habitat statistiques reposent sur une modélisation des distributions en fréquence des variables hydrauliques. Ils sont simples d'utilisation mais ne sont pas applicables en l'état en milieu insulaire tropical. Nous avons développé des modèles biologiques de préférences hydrauliques de 15 taxons diadromes des îles tropicales (crevettes et poissons), ainsi que des modèles hydrauliques statistiques adaptés aux rivières à forte pente et forte granulométrie. Les modèles utilisent cinq jeux de données biologiques existants (~8350 échantillons de pêches électriques, 52 rivières) et des mesures hydrauliques originales (44 rivières, 69 station×date), collectés dans quatre îles des Caraïbes (Guadeloupe, Martinique) et de l'Océan Indien (Mayotte, Réunion), en collaboration avec des partenaires locaux. Nos modèles hydrauliques statistiques prédisent les distributions de vitesses et de hauteurs d'eau observées avec plus de précision que les modèles développés en Europe continentale. Les modèles biologiques reflètent que les contraintes hydrauliques contribuent généralement faiblement à la sélection du microhabitat en milieu tropical. Néanmoins, certains taxons montrent des préférences hydrauliques significatives et comparables entre les jeux de données. Nous illustrons l'application possible des résultats pour guider la gestion des débits / Hydraulic habitat models are frequently used for predicting the ecological impacts of flow management in stream reaches. Their hydraulic component describes microhabitat hydraulics within the reach (e.g. velocity, depth); their biological component describes the "preferences" of aquatic taxa for microhabitat hydraulics. Statistical habitat models involve the modelling of the frequency distributions of hydraulic variables in reaches. Their application requires simple data, but such models are not available for insular tropical streams. We developed hydraulic preference models for 15 diadromous taxa of tropical islands (shrimps and fishes), and statistical hydraulic models for steep streams with large bed particle size. Our models are based on five available biological data sets (~8350 electrofishing units, 52 streams) and original hydraulic measurements (44 streams, 69 site×date) collected in four islands in the Caribbean region (Guadeloupe, Martinique) and the Indian Ocean (Reunion, Mayotte), in collaboration with local partners. Our hydraulic models improve the predictions of observed velocity and depth distributions when compared with previous models developed in continental Europe. Our biological models reflect that hydraulics contribute less to microhabitat selection in tropical islands than elsewhere. Nevertheless, some taxa have significant hydraulic preferences that are comparable among data sets and we illustrate a potential application of our results for guiding low flow management in tropical insular streams

El presente trabajo de investigación trata de la influencia de la inclinación de pozas disipadoras en la pérdida de energía en ríos de alta pendiente. Para ello, se tomó como caso de estudio la bocatoma San Pedro (Ayacucho, Perú). Se presenta el modelamiento numérico de la bocatoma en el software de dinámica de fluidos computacional, IBER, con el fin de obtener resultados hidráulicos en la estructura: tirante, velocidad, energía, Froude y tensión de fondo. El principal objetivo es mejorar la eficiencia del funcionamiento de las pozas disipadoras en ríos de alta pendiente. Asimismo, conocer las características hidráulicas del río San Pedro, que representa un flujo de alta pendiente. La metodología empleada fue la recoilación de información del caso de estudio, la cual fue validada con los resultados de los modelamientos en los programas HEC-RAS e IBER. Del mismo modo, se diseñaron 5 bocatomas con pozas disipadoras de distintas pendientes: 0%, 1.52%, 3.04%, 4.56% y 6.08%. Se modelaron en el software IBER y se exportaron los resultados a Excel. Estos modelos numéricos fueron validados mediante el Análisis de Sensibilidad. En consecuencia, se compararon los valores de energía aguas abajo de las distintas pozas propuestas. Finalmente, con los resultados del estudio se concluye que la poza disipadora de 3.04% es la más apropiada para el río San Pedro, pues pierde un 30% de energía más con respecto a la poza horizontal y reduce la velocidad en 4.9% en comparación a la poza de inclinación de 6.08%. / This research work deals with the influence stilling basin slope on energy loss in high slope rivers. Taking as a case study the water intake San Pedro (Ayacucho, Peru). Numerical modeling of water intake is presented in computational fluid dynamics software, IBER, in order to obtain the hydraulic results in the structure: hydraulic depth, velocity, energy, Froude and shear stress. The main objective is to improve efficiency of stilling basins operation in rivers with high slope. Also, know the hydraulic characteristics of the San Pedro River, which represents a high slope river. The methodology used was the collection of case study information, was validated with the results of modeling in the HEC-RAS and IBER programs. Similarly, five dissipation basins of different slopes were modeled: 0%, 1.52%, 3.04%, 4.56% and 6.08%. They were modeled in IBER software, and the results were exported to Excel. These numerical models were validated by Sensitivity Analysis. Consequently, the downstream energy values of the different proposed stilling basins were compared. Finally, the results of the study conclude that the 3.04% slope dissipative basin is the most appropriate for the San Pedro river, as it loses 30% more energy than the horizontal basin and reduces the velocity by 4.9% compared to the 6.08% inclined basin. This proposed stilling basins will feature an alphaizer on the End of the breakwater that will be calculated with Peterka's monograph shown in the bibliography. / Tesis

Edge computing requires highly energy efficient microprocessor units with embedded non-volatile memories to process data at IoT sensor nodes. Ferroelectric non-volatile memory devices are fast, low power and high endurance, and could greatly enhance energy-efficiency and allow flexibility for finer grain logic and memory. This paper will describe the basics of ferroelectric devices for both hysteretic (non-volatile memory) and negative capacitance (steep slope switch) devices, and then project how these can be used in low-power logic cell architectures and fine-grain logic-in-memory (LiM) circuits.

With project I present a make more attractive part of the territory of the dam, through which I bring two new paths for visitors from the coast and the other from the surface. The overall objective of the procejt is to attract visitors to the dam for more than one day trip or just a walk. The number of hotels and guesthouses on the dam is excessive. I have therefore decided to offer nature lovers accommodation in the country in the immediate vicinity of water while ensuring the necessary comfort. The objective of the present proposal is to present a potential year-round use options of Brno dam - Spa in the frozen surface of the dam, accommodation for schools, and summer camps could revitalize this part even during other year periods.