Made available in DSpace on 2015-04-09T12:28:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-02-18Bitstream added on 2015-04-09T12:47:17Z : No. of bitstreams: 1 000813391.pdf: 1986149 bytes, checksum: d81810d695d36601d15589bb10e0ea44 (MD5) / A forma mais simples de apresentar os três episódios que compõem este trabalho é supor que o argentino Jorge Luis Borges ocupe provisoriamente o centro duma rede de obras e de escritores de ficção científica hermética latino-americana – uma rede que pode ser lida como uma conspiração. A figura de Borges – mistura heterodoxa de literatura e de “vida”, de revelações, de epifanias, de “mentiras verdadeiras”, de excessos intelectuais – permite ingressar na tradição da ficção científica herege desde o instante inicial quando os conquistadores invadiram o território que ainda não era América. O “kairós” histórico, político, cultural, ideológico, econômico do desencontro dessas duas cosmovisões provocou uma “guerra de imagens” e de discursos em cujo fragor mestiçaram-se desejos milenaristas europeus e concepções ameríndias também proféticas, também transcendentes e com idêntica impossibilidade – como o sonho dos seus invasores – de ser utopia em uma “terra sem mal”. Nessas heterodoxias misturadas – caóticas, potentes para pensar e híbridas na sua origem europeia – cozinhou-se o húmus da ficção científica hermética que, com maior ou menor intensidade, fermentou até explodir no século XX. Em consequência, o gnóstico e cabalístico Borges é um mecanismo textual, com suas árduas especulações e com suas conspirações, para ler duas linhas genéricas surgidas desse húmus herege – linhas que, por nascer dos códigos do pensamento heterodoxo, são principais, porém não únicas. A primeira eclode no século XVII entre Brasil e Lisboa. Responde à ideia do complô, da conquista do espaço, da invasão, do domínio total (macrocosmo). O padre jesuíta Antônio Vieira baseado no milenarismo português constrói, no contexto de uma vida polêmica, um peculiar córpus composto de sermões apocalípticos e satíricos; uma carta-tratado (“papel”) que justifica um silogismo ... / El camino más directo para presentar estos tres episodios es suponer que el argentino Jorge Luis Borges ocupa –de forma provisoria- el centro de una red de obras y de escritores de ciencia ficción hermética latinoamericana –red que puede ser leída como una conspiración. La figura de Borges –mezcla heterodoxa de literatura y de ´vida´, de revelaciones, de epifanías, de ´mentiras verdaderas´, de excesos intelectuales- permite acceder a esa tradición de ciencia ficción hereje desde el instante inicial en el que los conquistadores invadieron el territorio que no era América todavía. El ´kairós´ histórico, político, cultural, ideológico, económico del desencuentro de dos cosmovisiones provocó una ´guerra de imágenes´, y de discursos, en cuyo fragor se mestizaron anhelos milenaristas europeos y concepciones amerindias también proféticas, también trascendentes y con idéntica imposibilidad -que el sueño de sus invasores- de resultar utopía en una ´tierra sin mal´. En esas heterodoxias mezcladas -caóticas, potentes para pensar y ya híbridas en su origen europeo- se cocinó el humus de la ciencia ficción hermética que, con mayor o menor intensidad, fermentó por centurias hasta explotar en el siglo XX. El gnóstico y cabalístico Borges es, entonces, un mecanismo textual, con sus arduas especulaciones y con sus conspiraciones, para leer dos líneas genéricas surgidas de ese humus hereje -líneas que al desprenderse de los códigos del pensamiento heterodoxo son principales, pero no únicas. La primera eclosiona en el siglo XVII entre Brasil y Lisboa. Responde a la idea de complot, de conquista del espacio, de invasión, de dominio total (´macrocosmos´). El padre jesuita Antônio Vieira en base al milenarismo portugués construye, en el entramado no menos polémico de su vida, un peculiar corpus compuesto por sermones apocalípticos y satíricos; una carta-tratado (´papel´) que justifica un silogismo ...

This thesis addresses the epistolary work by Novo-Hispanic writer Sor Juana Inés de la Cruz to place it in the literary and discursive context of the end of the 17th Century. I will take as theoretical background the concepts of dialogism and the carnivalesque by Mikhail Bakhtin, as well as Michel De Certeau’s reflections on what he calls the practice of everyday life. Other aspects of my theoretical approach will be drawn from Michel Foucault’s concepts in The Archaeology of Knowledge; his ideas about power, knowledge and social control, which will be useful for contextually addressing Sor Juana’s work and that of her intellectual contemporaries. Particularly, I will analyse the circumstances in which these Novo-Hispanic discourses were produced. This contextualization will allow me to incorporate not only the cultural (everyday life) practices that surround the production of these texts, but also other less notable or unpublished documents written by some of Sor Juana’s contemporaries. My aim is to widen the discursive spectrum of authors and critics of the prose of this author, and to this end I make use of documents from the 17th Century as primary source. This thesis is divided into three chapters. In the first, I will place into context the Novo-Hispanic discourse and the generic forms of the time: sermon, satire, libel, letter and inquisitorial censure, and the function of ideological control exerted by the Novo-Hispanic Holy Office. In the second chapter I will make a textual and contextual revision of three epistolary documents by Sor Juana: Carta al Padre Nuñez (Letter to Father Nuñez, 1682), Carta Atenagórica (Letter Worthy of Athena, 1690) and Respuesta a Sor Filotea de la Cruz (Reply to Sor Filotea of the Cross, 1690); as well as the antecedents, development and the result of the critical-theological conflict caused by these private letters, their replies and other collateral documents, namely, Carta de Serafina de Cristo, and Carta de Filotea de la Cruz (1690). Both drafts of these letters, found in Puebla in 2010, will also be refered in this revision. In addition to this I will study Defensa del Sermón del Mandato (1691) and Discurso Apologético contra la Fe de Erratas de un Soldado Castellano (1691), documents found in Lima in 2002 and published in Mexico in 2004. The third chapter consists of the study of three contemporary preachers of Sor Juana: Francisco Xavier Palavicino Villarrasa, Pedro Muñoz de Castro and Pedro de Avendaño Suárez de Sousa, whose theological and literary activities were denounced by the Holy Office. My aim is to show the reach of inquisitorial control and its consequence on the writing and literary activities of the contemporary intellectuals of Sor Juana, to contextualize Sor Juana’s epistolary work and confront the possible isolation and singularization that may place her life and work apart from the kernel of the intellectual scene in the New Spain at the close of the 17th Century.

This is an ethnographic study that focuses on Zahmanê Êzîdîa Li Dalarna, the Yezidi cemetery, in Borlänge. The Swedish town of Borlänge has one of the largest Yezidi diaspora communities in Western Europe; a majority emigrated from the Northern Iraqi region of Sheikhan during the 1990s and early 2000s. The overall aim of this project is to investigate how the Yezidi community in Borlänge puts Zahmanê Êzîdîa Li Dalarna into use, the meanings ascribed to the site by individual interviewees, and how these relate to ritual places and practices in Sheikhan. The empirical material stems from observations and interviews among members of three extended Yezidi families in Borlänge and in Sheikhan, and archival material from the Church of Sweden. Fieldwork in Sheikhan focused on the valley of Lalish and the cemetery sites in the Yezidi villages in Sheikhan. The empirical material is presented, analysed and discussed through a theoretical framework of place, creation and maintenance of social memory through ritual practice, and the concept of transfer of ritual. The empirical material reveals that salient ritual actions and elements from ceremonies in Lalish and the Yezidi villages in Sheikhan are transferred to Borlänge, and there put into use for ritual practices and for creating and maintaining a collective identity outside of Iraq.

Kronecker structured representations are used to cope with the state space explosion problem in Markovian modeling and analysis. Currently an open research problem is that of devising strong preconditioners to be used with projection methods for the computation of the stationary vector of Markov chains (MCs) underlying such representations. This paper proposes a block SOR (BSOR) preconditioner for hierarchical Markovian Models (HMMs) that are composed of multiple low level models and a high level model that defines the interaction among low level models. The Kronecker structure of an HMM yields nested block partitionings in its underlying continuous-time MC which may be used in the BSOR preconditioner. The computation of the BSOR preconditioned residual in each iteration of a preconditioned projection method becoms the problem of solving multiple nonsingular linear systems whose coefficient matrices are the diagonal blocks of the chosen partitioning. The proposed BSOR preconditioner solvers these systems using sparse LU or real Schur factors of diagonal blocks. The fill-in of sparse LU factorized diagonal blocks is reduced using the column approximate minimum degree algorithm (COLAMD). A set of numerical experiments are presented to show the merits of the proposed BSOR preconditioner.

Hierarchical Markovian Models (HMMs) are composed of multiple low level models (LLMs) and high level model (HLM) that defines the interaction among LLMs. The essence of the HMM approach is to model the system at hand in the form of interacting components so that its (larger) underlying continous-time Markov chain (CTMC) is not generated but implicitly represented as a sum of Kronecker products of (smaller) component matrices. The Kronecker structure of an HMM induces nested block partitionings in its underlying CTMC. These partitionings may be used in block versions of classical iterative methods based on splittings, such as block SOR (BSOR), to solve the underlying CTMC for its stationary vector. Therein the problem becomes that of solving multiple nonsingular linear systems whose coefficient matrices are the diagonal blocks of a particular partitioning. This paper shows that in each HLM state there may be diagonal blocks with identical off-diagonal parts and diagonals differing from each other by a multiple of the identity matrix. Such diagonal blocks are named candidate blocks. The paper explains how candidate blocks can be detected and how the can mutually benefit from a single real Schur factorization. It gives sufficient conditions for the existence of diagonal blocks with real eigenvalues and shows how these conditions can be checked using component matrices. It describes how the sparse real Schur factors of candidate blocks satisfying these conditions can be constructed from component matrices and their real Schur factors. It also demonstrates how fill in- of LU factorized (non-candidate) diagonal blocks can be reduced by using the column approximate minimum degree algorithm (COLAMD). Then it presents a three-level BSOR solver in which the diagonal blocks at the first level are solved using block Gauss-Seidel (BGS) at the second and the methods of real Schur and LU factorizations at the third level. Finally, on a set of numerical experiments it shows how these ideas can be used to reduce the storage required by the factors of the diagonal blocks at the third level and to improve the solution time compared to an all LU factorization implementation of the three-level BSOR solver.

Ce mémoire traite de l’influence des Lumières sur la pensée philosophique et musicale du compositeur et guitariste Fernando Sor (1778-1839). Cette influence peut être déclinée en trois thèmes, autour desquels le présent travail est structuré. Le premier thème, qui est omniprésent dans la Méthode pour la guitare de Sor (Paris, 1830), est celui de l’usage de la raison opposé à l’obéissance aveugle à une autorité. Le deuxième thème, présent lui aussi dans la Méthode, est celui de l’harmonie conçue comme une science permettant d’établir les rapports naturels qui existent entre les sons. Le troisième thème, présent quant à lui dans des chansons à caractère politique composées par Sor entre 1808 et 1832, est celui de la recherche de liberté face à l’oppression. Nous verrons dans ce mémoire que la manière dont la raison, l’harmonie et la liberté se manifestent dans les écrits et les œuvres de ce pionnier de la guitare classique est similaire à la manière dont ces trois mêmes notions sont représentées dans l’Encyclopédie de Diderot et d’Alembert, Sor faisant d’ailleurs référence à cet ouvrage emblématique du siècle des Lumières dans sa Méthode. D’autre part, nous verrons que le guitariste a aussi été influencé par les écrits de figures importantes associées au classicisme français, comme Descartes en ce qui concerne la raison et Rameau en ce qui concerne la notion de basse fondamentale (ces deux auteurs étant d’ailleurs cités dans l’Encyclopédie). En somme, ce mémoire permet de mieux définir le concept d’« influence des Lumières chez Sor » qui restait autrement plutôt flou dans la littérature secondaire publiée à ce jour. / This master’s thesis deals with the influence of the Enlightenment on the philosophical and musical thought of the composer and guitarist Fernando Sor (1778-1839). This influence can be divided into three themes, around which this project is structured. The first theme, which is omnipresent in Sor’s Méthode pour la guitare (Paris, 1830), is that of the use of reason opposed to a blind submission to authority. The second theme, also present in the Méthode, is that of harmony seen as a science that establishes the natural relationships that exist between sounds. The third theme, present in political songs composed by Sor between 1808 and 1832, is that of the struggle of freedom against tyranny. In this thesis, we will see that the way reason, harmony and freedom are conceived in Sor’s work is heavily influenced by Diderot and d’Alembert’s Encyclopédie, which is mentioned in the Méthode. On the other hand, we will see that the guitarist was also influenced by the writings of major figures associated with French classicism, such as Descartes when it comes to reason and Rameau when it comes to the notion of basse fondamentale (both of whom are mentioned in the Encyclopédie). In short, this master’s thesis helps to better understand how the Enlightenment influenced Sor, a subject that was otherwise mostly absent from the secondary literature.

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The pressure on clean and sustainable energy supplies is increasing. In this regard energy conversion by electrochemical processes plays a major role, for both fuel cell reactions and electrolysis reactions. The sulphur dioxide oxidation reaction (SOR) is a common reaction found in the Hybrid Sulphur Cycle (HyS) and the HyS is a way to produce large-scale hydrogen (H2). The problem with the use of the HyS and fuel cells is the cost involved as large amounts of Pt are required for effective operation. The aim of the study was to determine whether there was an alternative catalyst which was more efficient and cost-effective than Pt. The oxygen reduction reaction (ORR), the ethanol oxidation reaction (EOR) and SOR were studied by means of different electrochemical techniques (cyclovoltammetry (CV), linear polarization (LP) and rotating disk electrode (RDE)) on polycrystalline platinum (Pt) and palladium (Pd). The SRR and EOR are common reactions occurring at the cathode and anode, respectively, in fuel cells and these reactions have been investigated extensively. The reason for studying the reactions was as a preparation for the SOR. This study compared polycrystalline Pt and Pd for the different reactions, with the main focus on the SOR as Pd is considerably cheaper than Pt, and for the SOR polycrystalline Pd has by no means been investigated intensively. Polycrystalline Pt and Pd were compared by different electrochemical techniques and analyses. The Koutecky-Levich and Levich analyses were used to (i) calculate the number of e- involved in the relevant reaction, (ii) to determine whether the reaction was mass transfer controlled at high overpotentials and (iii) whether the reaction mechanism changed with potential. Next the kinetic current density ( k) was calculated from Koutecky-Levich analyses, which was further used for Tafel slope analyses. If it was not possible to carry out the analyses, the activation energy (Ea) was used to determine the electrocatalytic activity of the catalyst. The electrocatalytic activity was also determined by comparing onset potentials (Es), peak potentials (Ep) and limited/maximum current density ( b/ p) of each catalyst. This study was only a preliminary study for the SOR and therefore, further studies are certainly required. It seemed Pd shows better electrocatalytic activity than Pt for the SRR in an alkaline electrolyte because of similar Es, but Pd produced a higher cathodic current density. Pt showed a lower Es than Pd for the SRR in an acid electrolyte, but Pd delivered a higher cathodic current density. This, therefore, means that the SRR in an acid electrolyte is kinetically more favourable on Pd than on Pt. For the EOR better electrocatalytic activity was obtained with Pd than with Pt in an alkaline electrolyte due to higher current densities at lower potentials and Pd showed lower Ea values than Pt in the potential range normally used for fuel cells. Pd was inactive for EOR in an acid electrolyte, while a reaction occurred on Pt. A possible reason for this observation may be due to the H2 absorbing strongly on Pd thus blocking the active positions on the electrode surfaces, preventing further reaction. Pd showed higher electrocatalytic activity for the SOR due to lower Es and higher current densities at low potentials. From the RDE studies it was established that the SRR in an alkaline electrolyte on polycrystalline Pt and Pd was mass transfer controlled at low potentials (high overpotentials), but the SRR in an acid electrolyte was only mass transfer controlled on Pt. The SOR was not mass transfer controlled on polycrystalline Pt and Pd at high potentials (high overpotentials). These assumptions were confirmed by Levich analysis. Using Koutecky-Levich analysis, it was determined that the reaction mechanism on polycrystalline Pt and Pd changed with potential for SRR in an alkaline electrolyte and the SOR. For the SRR in an acid electrolyte the reaction mechanism remained constant with changes in potential on polycrystalline Pd, but the reaction mechanism on polycrystalline Pt changed with potential. These assumptions were confirmed by the number of e-, calculated using Koutecky-Levich analyses. Levich and Koutecky-Levich analyses were not performed for EOR as an increase in rotation speed did not produce an increase in current density. Tafel slope analyses were conducted by making use of overpotentials and k, where possible. As in the case of ethanol, it was not possible to execute Koutecky-Levich analyses and, therefore, it was not possible to perform Tafel slope analyses using k. Tafel slope analyses for the EOR was therefore performed with normal current densities at 0 rotations per minute (rpm). The reaction mechanisms on Pt and Pd for the SRR in alkaline and acidic electrolytes differed due to different Tafel slopes. Pt and Pd displayed similar Tafel slopes for the EOR in alkaline electrolyte, thus suggesting that the reaction mechanisms on Pt and Pd were the same. For the SOR it seemed that the reaction mechanism on Pt and Pd were similar because of similar Tafel slopes. This was only a preliminary and comparative study for polycrystalline Pt and Pd, and the reaction mechanism was not further studied by means of spectroscopic techniques. / MSc (Chemistry), North-West University, Potchefstroom Campus, 2014

The pressure on clean and sustainable energy supplies is increasing. In this regard energy conversion by electrochemical processes plays a major role, for both fuel cell reactions and electrolysis reactions. The sulphur dioxide oxidation reaction (SOR) is a common reaction found in the Hybrid Sulphur Cycle (HyS) and the HyS is a way to produce large-scale hydrogen (H2). The problem with the use of the HyS and fuel cells is the cost involved as large amounts of Pt are required for effective operation. The aim of the study was to determine whether there was an alternative catalyst which was more efficient and cost-effective than Pt. The oxygen reduction reaction (ORR), the ethanol oxidation reaction (EOR) and SOR were studied by means of different electrochemical techniques (cyclovoltammetry (CV), linear polarization (LP) and rotating disk electrode (RDE)) on polycrystalline platinum (Pt) and palladium (Pd). The SRR and EOR are common reactions occurring at the cathode and anode, respectively, in fuel cells and these reactions have been investigated extensively. The reason for studying the reactions was as a preparation for the SOR. This study compared polycrystalline Pt and Pd for the different reactions, with the main focus on the SOR as Pd is considerably cheaper than Pt, and for the SOR polycrystalline Pd has by no means been investigated intensively. Polycrystalline Pt and Pd were compared by different electrochemical techniques and analyses. The Koutecky-Levich and Levich analyses were used to (i) calculate the number of e- involved in the relevant reaction, (ii) to determine whether the reaction was mass transfer controlled at high overpotentials and (iii) whether the reaction mechanism changed with potential. Next the kinetic current density ( k) was calculated from Koutecky-Levich analyses, which was further used for Tafel slope analyses. If it was not possible to carry out the analyses, the activation energy (Ea) was used to determine the electrocatalytic activity of the catalyst. The electrocatalytic activity was also determined by comparing onset potentials (Es), peak potentials (Ep) and limited/maximum current density ( b/ p) of each catalyst. This study was only a preliminary study for the SOR and therefore, further studies are certainly required. It seemed Pd shows better electrocatalytic activity than Pt for the SRR in an alkaline electrolyte because of similar Es, but Pd produced a higher cathodic current density. Pt showed a lower Es than Pd for the SRR in an acid electrolyte, but Pd delivered a higher cathodic current density. This, therefore, means that the SRR in an acid electrolyte is kinetically more favourable on Pd than on Pt. For the EOR better electrocatalytic activity was obtained with Pd than with Pt in an alkaline electrolyte due to higher current densities at lower potentials and Pd showed lower Ea values than Pt in the potential range normally used for fuel cells. Pd was inactive for EOR in an acid electrolyte, while a reaction occurred on Pt. A possible reason for this observation may be due to the H2 absorbing strongly on Pd thus blocking the active positions on the electrode surfaces, preventing further reaction. Pd showed higher electrocatalytic activity for the SOR due to lower Es and higher current densities at low potentials. From the RDE studies it was established that the SRR in an alkaline electrolyte on polycrystalline Pt and Pd was mass transfer controlled at low potentials (high overpotentials), but the SRR in an acid electrolyte was only mass transfer controlled on Pt. The SOR was not mass transfer controlled on polycrystalline Pt and Pd at high potentials (high overpotentials). These assumptions were confirmed by Levich analysis. Using Koutecky-Levich analysis, it was determined that the reaction mechanism on polycrystalline Pt and Pd changed with potential for SRR in an alkaline electrolyte and the SOR. For the SRR in an acid electrolyte the reaction mechanism remained constant with changes in potential on polycrystalline Pd, but the reaction mechanism on polycrystalline Pt changed with potential. These assumptions were confirmed by the number of e-, calculated using Koutecky-Levich analyses. Levich and Koutecky-Levich analyses were not performed for EOR as an increase in rotation speed did not produce an increase in current density. Tafel slope analyses were conducted by making use of overpotentials and k, where possible. As in the case of ethanol, it was not possible to execute Koutecky-Levich analyses and, therefore, it was not possible to perform Tafel slope analyses using k. Tafel slope analyses for the EOR was therefore performed with normal current densities at 0 rotations per minute (rpm). The reaction mechanisms on Pt and Pd for the SRR in alkaline and acidic electrolytes differed due to different Tafel slopes. Pt and Pd displayed similar Tafel slopes for the EOR in alkaline electrolyte, thus suggesting that the reaction mechanisms on Pt and Pd were the same. For the SOR it seemed that the reaction mechanism on Pt and Pd were similar because of similar Tafel slopes. This was only a preliminary and comparative study for polycrystalline Pt and Pd, and the reaction mechanism was not further studied by means of spectroscopic techniques. / MSc (Chemistry), North-West University, Potchefstroom Campus, 2014