La détection, la localisation et le suivi de l’évolution de défauts dans les milieux périodiques et les guides d’ondes est un enjeu majeur dans le domaine du Contrôle Non Destructif (CND). La propagation d’ondes dans ce genre de milieux est complexe, par exemple lorsque la vitesse dépend de la fréquence (dispersion) ou de la direction de propagation (anisotropie). La signature du défaut peut également être « noyée » dans le champ acoustique renvoyé par la structure (réverbération ou diffusion multiple). C’est pour répondre à ces enjeux de taille que l’Optimisation Topologique (OT) a été adaptée aux problèmes de diffraction des ondes acoustiques par des défauts infinitésimaux afin d’obtenir des images de réflectivité des milieux inspectés. La méthode peut être appliquée à toutes sortes de milieux, quelle que soit leur complexité, à condition d’être capable de simuler correctement (sur un milieu de référence) la propagation des ondes de l’expérience physique. En s’inspirant de l’OT, les travaux de cette thèse proposent de mettre en oeuvre des méthodes d’imagerie qualitatives adaptées aux spécificités des Cristaux Phononiques (CP) et des guides d’ondes. Dans un premier temps, nous nous attachons à la description du formalisme mathématique de l’Optimisation Topologique et de la Full Waveform Inversion (FWI). Bien que ces méthodes ne cherchent pas à résoudre les mêmes problèmes inverses, nous mettons en évidence leurs points communs. Dans un deuxième temps, nous appliquons l’Imagerie Topologique (IT) à l’inspection en réflexion des milieux faiblement hétérogènes. Dans un troisième temps, nous nous inspirons de l’IT pour définir une nouvelle variante de celle-ci nommée Imagerie Topologique Hybride (ITH). Nous appliquons ces méthodes pour l’inspection en réflexion des CP crées par des tiges d’acier immergées dans l’eau. Nous comparons les performances de ces méthodes en fonction du type de défaut dans le CP. Les simulations numériques correspondantes à certains cas d’étude sont appuyées par des essais expérimentaux concluants. Dans un quatrième temps, nous adaptons l’IT à une configuration d’inspection en transmission afin de mette en oeuvre une méthode de Structural Health Monitoring (SHM) des guides d’ondes. A ce propos, nous avons mis au point une nouvelle méthode d’imagerie mieux adaptée que l’IT aux configurations d’inspection en transmission. / The detection, localization and monitoring of the evolution of defects in periodic media and waveguides is a major issue in the field of Non-Destructive Testing (NDT). Wave propagation in such media is complex, for example when the velocity depends on the frequency (dispersion) or direction of propagation (anisotropy). The signature of the defect can also be "embedded" in the acoustic field reflected by the structure (reverberation or multiple diffusion). It is to answer these stakes of the size that the Topological Optimization (TO) has been adapted to the problems of diffraction of the acoustic waves by infinitesimal defects in order to obtain reflectivity images of the inspected media. The method can be applied to all kinds of media, regardless of their complexity, provided an exact simulation of the wave propagation in a reference medium (without defects) is performed. Inspired by the TO, the work of this thesis proposes to implement qualitative imaging methods adapted to the specificities of Phononic Crystals (PC) and waveguides. First, we focus on the description of the mathematical formalism of Topological Optimization and Full-Waveform Inversion (FWI). Although these methods do not try to solve the same inverse problems, we highlight their similarities. In a second step, we apply Topological Imaging (TI) to the inspection in pulse-echo configuration of weakly heterogeneous media. Thirdly, we draw inspiration from TI to define a new variant of this method called Hybrid Topological Imaging (HTI).We apply these methods for the pulse-echo configuration inspection of PCs created by steel rods immersed in water.We compare the performance of these methods according to the kind of defects in the PC. Numerical simulations for some case studies are supported by conclusive experimental trials. In a fourth step, we adapt the TI to a pitch-catch configuration in order to implement a new method of Structural Health Monitoring (SHM) of waveguides. In this regard, we have developed a new imaging method that is better suited than TI to pitch-catch configurations.

The VAT treatment of over-allowances in the motor retail industry has proved contentious for South African Revenue Services (“SARS”). VAT legislation dictates that notional VAT may be claimed on the lower of the open market value and the consideration paid. The industry, however, claims notional VAT on the actual consideration paid for a used vehicle on the basis that a higher output VAT will be declared on the consequent sale of the new vehicle. This is because the over-allowance is offset against the lower discount granted. SARS allows this practice on account of SARS’ own issuance of a binding general ruling, provided certain criteria are met. This ruling is contained in the VAT Guide to Motor Dealers. This study performs an analysis of the current practice by South African motor retailers pertaining to over-allowances. The aim of the study is to determine the impact on the industry of the issuance of the Guide, both practically and from the perspective of compliance, focussing on VAT legislation and Competition Commission legislation. The study discusses the requirements contained in the Guide in the light of the Competitions Act and the practical benefits, and concludes that the industry is satisfied with the issuance of the Guide, despite its silence on the interpretation of certain key criteria. The industry has chosen to assume that, as SARS has acted reasonably in the issuance of the Guide, it would not expect the industry to deviate from any other legislation, including the Competitions Act. If SARS is not satisfied with this interpretation, the Guide will have to be amended to include definitions of terms such as “permissible discount”. AFRIKAANS : Die hantering van die toelating van oormatige BTW in die motorvoertuig-kleinhandelsindustrie is, insover dit die Suid-Afrikaanse Inkomstediens (“SAID”) betref, omstrede. BTW-wetgewing bepaal dat geagte BTW gehef mag word op die laagste van ope markwaarde en die werklike bedrag betaal. In die motorvoertuigindustrie word BTW egter altyd gehef op die werklike bedrag betaal vir ‘n gebruikte voertuig met die veronderstelling dat hoër uitset BTW verklaar gaan word met die verkoop van ‘n nuwe voertuig wat die inruiltransaksie tot gevolg gaan hê. Daar word geredeneer dat die oortoelating van BTW uitgekanselleer gaan word deur ‘n laer afslag op die nuwe verkope. As gevolg van bindende bepalings in die BTW Handleiding vir Motorhandelaars, wat uitgereik is deur die SAID en die nakoming van sekere voorwaardes deur die motorhandelaars, laat die SAID hierdie praktyk toe. In hierdie mini-verhandeling word die vereistes wat in die Handleiding vervat is teen die agtergrond van die Wet op Mededinging en die praktiese voordele daarvan bespreek. Die gevolgtrekking is dat die motorvoertuigindustrie tevrede is met die uitreiking van die Handleiding vir motorhandelaars ongeag die feit dat sekere sleutel aspekte nie in die Handleiding voldoende toegelig word nie. Die motorindustrie het die aanname gemaak dat SAID redelikerwys opgetree het deur die Handleiding uit te reik en sal daarom nie verwag dat die industrie van enige ander wetgewing sal afwyk nie, insluitende die Wet op Mededinging. As die SAID nie tevrede is met hierdie interpretasie nie sal dit beteken dat die Handleiding aangepas sal moet word om ander relevante terminologieë soos “toelaatbare afslag” beter te omskryf en te verduidelik. Copyright 2011, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: Coventry, MA 2011, A critical analysis of the VAT implications of over-allowances in the South African motor retail industry, MCom dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-03092012-112915 / > F12/4/77/gm / Dissertation (MCom)--University of Pretoria, 2012. / Taxation / unrestricted

In this paper a new equivalent circuit is presented which describes the dynamics of a prototype micro-gyro sensor. The concept takes advantage of the principles employed in vibratory gyro sensors and the ductile attributes of GalFeNOL to target high sensitivity and shock tolerance. The sensor is designed as a tuning fork structure. A GalFeNOL patch attached to the y-z surface of the drive prong causes both prongs to bending the x-z plane (about the y axis) and a patch attached to the x-z surface of the sensing prong detects Coriolis-force induced bending in the y-z plane (about the x axis). A permanent magnet is bonded on top of each prong to give bias magnetic fields. A solenoid coil surrounding the drive prong is used to produce bending in the x-z plane of both prongs. The sensing prong is surrounded by a solenoid coil with N turns in which a voltage proportional to the time rate of change of magnetic flux is induced. The equivalent circuit enables the efficient modeling of a gyro sensor and an electromechanical behavioral simulation using the circuit simulator SPICE. The prongs are modeled as wave guiding bending beams which are coupled to the electromagnetic solenoid coil transducer. In contrast to known network approaches, the proposed equivalent circuit is the first tuning fork model, which takes full account of the fictitious force in a constant rotating frame of reference. The Coriolis force as well as the centrifugal force on a concentrated mass are considered.

Das vorliegende Handbuch gibt Bibliotheksangestellten, die sich mit der Aufbereitung und Einstellung von Webinhalten befassen, einen Einblick in die Problematik „Barrierefreiheit“. Dabei wird im Speziellen auf die Belange von Bibliotheken eingegangen und in diesem Zuge Richtlinien und Gesetze vorgestellt, die eine wichtige Rolle spielen. Anschließend wird auf die Barrieren eingegangen, die im Internet entstehen können. Zudem wird gezeigt, wie man diese Barrieren verhindert oder beseitigt. Das Handbuch gibt praktische Tipps, in dem es Hilfsmittel und Quellcode-Beispiel vorstellt, die zur barrierefreien Gestaltung eingesetzt werden können.

The objective of this dissertation is to review the discrepancies between Concert Sans Orchestre and Grande Sonate edited by Ernst Herttrich, Grosse Sonate No.3 Op.14 Erste and Zweite Ausgabe edited by Clara Schumann of Robert Schumann's No.3 Op.14, providing assistance for performers by clarifying inconsistencies between the three editions. Information in reference to major aspects such as notes, rhythms, metronome marking and expression signs is presented. Examples of discrepancies found throughout the first movement are discussed in Chapter 3. Suggested solutions are followed by each example.

The Cello Concerto in B-flat major, G.482, by Italian composer Luigi Boccherini (1743-1805), is the composer's most beloved work for the instrument, as well as one of the most performed pieces in the Classical concerto repertoire. Historically, cellists performing this work have used an edition prepared by German cellist Friedrich Grützmacher (1832-1903). However, an 'original' version that was discovered in 1949 is significantly different from that of Grützmacher. A comparison of both editions has revealed that Grützmacher in fact made considerable modifications to Boccherini's 'original.' Along with the issue of having two editions, cellists that have played the 'original' edition have noted that there are certain practical and interpretative matters that are not favorable to the cellist, particularly in terms of the way the music is notated and how it lacks many details. This dissertation provides clarity to these issues by undertaking a comprehensive analysis of both editions in order to make cellists become aware of the differences between both editions by comparing musical elements from a performance practice viewpoint. In addition, I discuss relevant issues that are present in the 'original' version, ultimately providing an alternative performance edition to this score that is based on historically informed performance (HIP) practices. Finally, I hope to draw attention on how a performance edition like this can be useful as a rare critical source to one of the major works from the eighteenth-century cello repertoire.

Ericssons Business Communication Suite (BCS) är en Unified Communication-lösning, och är avsedd för större företag och teleoperatörer. BCS erbjuder tjänster som snabbmeddelanden, videosamtal, lägga till kontakter i grupper samt grupphantering mm. Syftet med detta projekt var tvåfaldigt; att utveckla och integrera ett program som kan kommunicera med Ericssons BCS, samt att dokumentera denna integration genom de erhållna kunskaperna från utvecklingen. Applikationen utvecklades för Windows Sidebar widget miljön och BCS miljön simulerades med hjälp av flera program och applikationer som tillhandahölls av Ericsson. Det första resultatet är en steg-för-steg integrationsguide, som innehåller installationsintruktioner för BCS-miljön samt riktlinjer för denna integration. Det andra resultatet är en widget som kan söka efter personer på sökmotorn www.eniro.se och utnyttja tjänster som tillhandahålls från BCS, som kontakt-och grupphantering samt videosamtal. Detta projekt visar att en tredjepartsutvecklad applikation kan integreras med BCS, och att tredjepartsutvecklare samt anställda på Ericsson kan använda steg-för-steg integrationsguiden för att sätta upp test- och utvecklingsmiljö för BCS. / Ericsson Business Communication Suite (BCS) is a Unified Communication solution destined for larger companies and telecommunication operators. BCS offers services such as instant messaging, video calls, contact group management and much more. The purpose of this project was twofold; developing and integrating an application that could communicate with Ericsson's Business Communication Suite, but also to document this integration through the knowledge acquired from the development. The application was developed for the Windows Sidebar widget engine and a BCS environment was simulated with the help of several programs and applications provided by Ericsson. The results of the project are a step-by-step integration guide, which contains environment setup as well as integration guidelines, and also a widget application that can search for people on the search engine www.eniro.se and utilize services provided by BCS such as contact and group management and video calls. This project demonstrates that a third party developed application can be integrated with Ericsson BCS, and that third party developers and people at Ericsson can use the step-by-step integration guide to easily setup the necessary BCS test environments.

We have harnessed the power of programmable photonics devices for an interferometric measurement technique. Laser interferometers are widely used for flow velocity measurements, since they offer high temporal and spatial resolutions. However, often optical wavefront distortions deteriorate the measurement properties. In principle, adaptive optics enables the correction of these disturbances. One challenge is to generate a suitable reference signal for the closed loop operation of the adaptive optics. An adaptive Mach Zehnder interferometer is presented to measure through a dynamic liquid-gas phase boundary, which can lead to a misalignment of the interfering laser beams. In order to generate the reference signal for the closed loop control, the Fresnel reflex of the phase boundary is used as Laser Guide Star (LGS) for the first time to the best of the authors’ knowledge. The concept is related to the generation of artificial stars in astronomy, where the light transmitted by the atmosphere is evaluated. However, the adaptive interferometric flow velocity measurements at real world experiments require a different concept, since only the reflected light can be evaluated. The used LGS allows to measure the wavefront distortions induced by the dynamic phase boundary. Two biaxial electromagnetically driven steering mirrors are employed to correct the wavefront distortions. This opens up the possibility for accurate flow measurements through a dynamic phase boundary using only one optical access. Our work represents a paradigm shift in interferometric velocity measurement techniques from using static to dynamic optical elements.

Le confinement électrique et optique par oxydation des couches minces d'AlGaAs est une étape essentielle dans la réalisation des composants photoniques actifs et passifs dans la filière de matériaux GaAs. La recherche de performances ultimes sur ces composants nécessite une meilleure maîtrise du procédé d'oxydation ainsi qu'une meilleure connaissance des propriétés optiques de l'oxyde d'aluminium (AlOx). Dans cette perspective, j'ai d'abord réalisé une étude expérimentale de la vitesse d'oxydation des couches d'AlGaAs en fonction de la température du substrat, de la composition en gallium des couches étudiées, de la pression atmosphérique et de la géométrie des mesas considérés. Puis, j'ai établi un modèle anisotrope permettant une meilleure résolution spatiale et temporelle de la forme du front d'oxydation de l'AlAs. Enfin, j'ai exploité ce procédé pour réaliser des composants d'optique guidée notamment des micro-résonateurs puis réalisé des guides optiques à fente et caractérisé leurs performances optiques. / Optical and electrical confinement using Al(Ga)As layer oxidation is a key milestone in the fabrication of active and passive GaAs-based photonic components. To optimize those devices, through the control of the optical and electrical confinements, a better modelling of oxidation process and a better understanding of optical properties of aluminum oxide (AlOx) is required. One part of this work is focusing on a throughout experimental study of AlGaAs oxidation kinetics, where I studied different important parameters such as wafer temperature, gallium composition, atmospheric pressure and mesa geometry. Then, I developed a new predictive model taking into account the process anisotropy, thus allowing a better temporal and spatial of AlAs oxidation front evolution. Finally, I could exploit this technological process to realize whispering gallery mode microdisks as well as slot optical waveguides, and I have characterized this latter photonic devices.

In the world of chamber music, programmatic suites are more rarely composed and consequently more rarely presented in recital than other musical forms. Perhaps partially for this reason, George Enescu's Impressions d'enfance for violin and piano, his last chamber piece written in the tumultuous year of 1940, has been overlooked for a long time; even the composer himself did not make a recording of this seldom performed piece. This dissertation examines Impressions d'enface in order to explore the relationship between the underlying Romanian folk rhythmic and melodic patterns, to provide an analysis, as well as to serve as a performance guide to assist performers in surmounting the technical challenges and thus create a more effective ensemble. I hope this dissertation will encourage more duos to experiencing the joy of George Enescu's richly fulfilling Impressions d'enfance for themselves.