Submitted by Erika Demachki (erikademachki@gmail.com) on 2017-06-08T17:36:27Z No. of bitstreams: 2 Dissertação - Paulo Roberto Ferreira - 2017.pdf: 14996898 bytes, checksum: cdb17170fa3d2d81ae6bea7a5743f3a9 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-06-09T10:59:26Z (GMT) No. of bitstreams: 2 Dissertação - Paulo Roberto Ferreira - 2017.pdf: 14996898 bytes, checksum: cdb17170fa3d2d81ae6bea7a5743f3a9 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-06-09T10:59:26Z (GMT). No. of bitstreams: 2 Dissertação - Paulo Roberto Ferreira - 2017.pdf: 14996898 bytes, checksum: cdb17170fa3d2d81ae6bea7a5743f3a9 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-03-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The proposal of this dissertation is the development of an extracurricular project that meets the demand of students that are about to conclude high school, of notable knowing in mathematics and physics, specifically in basic electromagnetics. Using the theory of meaningful learning of David Ausubel, the proposal of this project is to incorporate through expositive classes concepts of differential and integral calculus, dot product and vector product of higher education exact sciences courses to the high school environment in order to help high school students that present resourcefulness in exact sciences and yearn for new knowledge. Such mathematical tools presented are going to serve as prior organizers, according to the meaningful learning theory, to the understanding of the pool of the four most influential equations of electromagnetism as a whole: Maxwell's equations. The immediate solutions of Maxwell's equations allow students to link new concept with subsumers already acquired in their regular classes, providing a more detailed view of formulas and concepts only quoted before without any previous reference. In this sense, the goal of this dissertation is not to teach the whole concepts pertinent to higher education, but sharpen the interest for the study area, which is already shown by most students interested in joining exact sciences, engineering courses and similars. Hence, the project improves the performances of apprentices in higher education entrance exams and foments interest in subjects which are classified as boring and difficult both to teach and to learn for most students, although fascinating. / A proposta desta dissertação é o desenvolvimento de um projeto extracurricular que atende à demanda de alunos concluintes do Ensino Médio, de saber notório em matemática, em física, especificamente em eletromagnetismo básico. Utilizando a teoria da aprendizagem significativa de David Ausubel, o objetivo deste projeto é trazer, por meio de aulas expositivas, noções de Cálculo diferencial e integral, produto escalar e produto vetorial, do domínio de cursos superiores de exatas para o ambiente do Ensino Médio de modo a auxiliar estudantes secundaristas que apresentam desenvoltura em exatas e anseiam por um novo saber. Tais ferramentas matemáticas apresentadas servirão como organizadores prévios, de acordo com a teoria da aprendizagem significativa, para o entendimento do conjunto das quatro equações mais influentes do eletromagnetismo na sua forma integral: as equações de Maxwell. As soluções imediatas das equações de Maxwell permitem que os alunos relacionem o novo conceito a subsunçores adquiridos em suas aulas regulares, proporcionando uma visão mais detalhada de fórmulas e de conceitos antes apenas citados e sem qualquer referência anterior. Nesse sentido, a função do presente trabalho não é de ensinar, na sua totalidade, conceitos pertinentes ao ensino superior, mas aguçar o interesse pela área de estudo, que já é demonstrado pela maioria dos estudantes interessados em ingressar em cursos de exatas, engenharias e afins. Dessa forma, o projeto aperfeiçoa as performances dos aprendizes em exames de ingresso ao ensino superior e fomenta o interesse por assuntos que, na maioria das vezes, são classificados como entediantes e difíceis tanto para ensinar quanto para aprender, embora sejam fascinantes.

The aim of this dissertation was to critically analyse Terry Pratchett’s Johnny Maxwell trilogy in terms of three areas, namely Pratchett’s use of various fantasy techniques; how comedy and satire function as distancing mechanisms; and how fantasy and comedy function in accordance with Erikson’s and Bettelheim’s theories concerning identity formation in adolescent and child readers. The primary aim of this dissertation was therefore to provide a literary reading of Pratchett’s trilogy, Only You Can Save Mankind (1992), Johnny and the Dead (1993) and Johnny and the Bomb (1996). However, it also acknowledges the possible didactic and developmental benefits of the books. The trilogy is entertaining, exciting, witty and child-friendly (Baldry cited in Butler, James and Mendlesohn, 2004:41), but it is also clear that Pratchett endeavours to challenge his child readers by presenting everyday situations from foreign and unusual perspectives. This dissertation argues that, as Baldry states, Pratchett ‘expands the thinking of his young readers with new ideas or unconventional ways of looking at familiar ideas’ which will ultimately help them consider their own lives in alternative and perhaps even more meaningful ways (quoted in Butler, James and Mendlesohn, 2004:41). The idea of ‘distancing techniques’ is vital for this study, because it proposes that readers can be transported from their Primary Realities (in which they live and function on a daily basis) into Secondary Realities or worlds which are unlike the Primary Reality in form and composition, but not unlike them in the way they function. Once this removal has taken place, bibliotherapists argue that readers are able to look back upon their primary world with new insight into their sense of industry and identity and also into the way their primary reality functions and the way they function within it. J.R.R. Tolkien (1985:35) explains that ‘…fact becomes that which is manipulated by the fantasy writer to produce a keener perception of the primary world and a greater ability to survive in it’. Owing to Pratchett’s specific comic brand of fantasy, a discussion of his comic and satiric techniques is also presented. Part of this discussion again concentrates on the ability of comedy to act as a distancing mechanism, while another discusses how Pratchett uses comedy to satirise certain aspects of society. As Bergson (1911:17) states in his book, Laughter: An Essay on the Meaning of the Comic, laughter is a way of ‘correcting men’s manners’. Pratchett thus makes use of various comic techniques to mock and ridicule certain features of society, such as its obsession with television, its materialism, or its obsession with computer games. This research is important as the fantasy genre is often considered to be mere popular fiction, to which parents and school teachers are frequently averse. However, with the increase in sales of fantasy works over the past decade, especially in adolescent and children’s fantasy, study of the genre and its possible influence on readers is becoming increasingly necessary. This dissertation undertakes to show that fantasy works can be both complex and satisfying literary works while they also have a positive influence on child readers. / Dissertation (MA)--University of Pretoria, 2013. / gm2014 / English / unrestricted

My dissertation examines the representations of materialism -- a philosophy stereotypically associated with a reductive, anti-theological and mechanistic world-picture -- in the published prose and (typically) unpublished poetry of several figures central to scientific discourse in the latter half of the nineteenth century, most notably W. K. Clifford, a mathematician, and John Tyndall, a physicist and media-savvy ‘champion of science’. These engagements, and representations, were not merely on the level of ‘direct’ argumentation, however. A self-consciously allusive, even polyphonous tone was far from uncommon in the many literatures arising from mid-Victorian scientific encounter, and this openness of form permitted both popularisers and critics of materialism to choose the vocabularies in which to relate their observations –- the texts with which they would engage –- towards specific ends. As I argue, such was a task they performed with great care and an often astonishing felicity: an essay on cosmology, after all, acquires quite a different colouration when interleaved with the cadences of Milton, another again if illustrated with quotations from Whitman or an epigram from ‘Tintern Abbey’. My 1st chapter provides a broader context for those that follow, analysing both changing nineteenth-century ideas of materialism and also a range of potential reactions to -– and inter alia a variety of the contrasting vernaculars used in illustration of –- contemporary metaphysical or ‘methodological’ materialism. My 2nd chapter offers a reading of Tyndall’s August 1874 Belfast Address, the locus classicus for practically all later elaborations of materialistic belief. My 3rd chapter contrasts the theologically orthodox position of James Clerk Maxwell (buttressed by allusions to the theologically doctrinaire George Herbert) with the radically atheistic and materialistic philosophy of Clifford (underpinned by the similarly atheistic Algernon Charles Swinburne). My 4th and 5th chapters are paired studies in the ‘private’ nuances of Tyndall’s ideology, elaborating on my 2nd chapter’s scrutiny of its more public attributes. The former discusses his notions of cosmic connectedness, ironically derived from the non-materialistic works of Carlyle. The latter examines both the exultancy and the despair explicit in Tyndall’s poetry and implicit in his prose. As I note in conclusion, such contrary emotions, phrased with striking clarity in Tyndall, are common in mid-Victorian writings concerning materialism, directly or indirectly. They are rooted in the hopes afforded by materialism’s explanatory prowess, on the one hand, and the ‘atrophy of spirit’ born of its austere, even dehumanising, epistemology, on the other; that is to say, in a salutary awareness of both power and pitfalls.

Comme introduction, nous présentons la formulation originale de la correspondance AdS/CFT, entre la théorie de Yang-Mills supersymétrique N = 4 avec groupe de jauge SU(N) et la théorie des supercordes de type IIB sur l'espace AdS5 x S5. Dans une première partie, nous montrons comment les ingrédients de la correspondance AdS/CFT peuvent être appliqués de manière phénoménologique à l'étude des systèmes de fermions fortement corrélés et présentons deux modèles fondamentaux, l'étoile à électrons et le supraconducteur holographique. Nous construisons un modèle holographique pour l'étude des systèmes de Bose-Fermi à densité finie et montrons que la présence simultanée de degrés de liberté bosoniques et fermioniques est favorisée à température nulle. En résolvant l'équation du mouvement d'un spineur test sur ces solutions, nous montrons que le système admet un grand nombre de surfaces de Fermi de type électron et/ou trou et un condensat scalaire chargé. Dans une seconde partie, nous nous intéressons à l'étude des solutions de trous noirs BPS asymptotiquement AdS4 dans la théorie de supergravité jaugée N = 2 en 4 dimensions. En utilisant les transformations de dualité dans un modèle STU simple, nous trouvons de nouvelles solutions de trous noirs BPS statiques et en rotation. / As an introduction, we present the original formulation of the AdS/CFT correspondence, between N = 4 Super Yang-Mills theory with gauge group SU(N) and type IIB string theory on AdS5 x S5. In a first part, we show how the ingredients of the AdS/CFT correspondence can be applied in a phenomenological way to study strongly correlated systems of fermions and present two fundamental models, the electron star and the holographic superconductor. We construct a holographic model for the study of Bose-Fermi systems at finite density and show that the simultaneous presence of bosonic and fermionic degrees of freedom is favoured at zero temperature. By solving the field equation of a probe spinor field in these solutions, we show that the system admits a large number of electron-like and/or hole-like Fermi surfaces and a charged scalar condensate. In a second part, we study asymptotically-AdS4 BPS black hole solutions in the N = 2 gauged supergravity theory. Using the duality transformations in a simple STU model, we find new static and rotating BPS black hole solutions.

This Thesis deals with problematics of residual current circuit breaker and its eventual operation malfunction due to DC components. There are magnetic phenomena described in details which occur inside of the apparatus. Consequently, there is proposed a mathematical model of the circuit breaker in Simulink program. The comparison of B-H curves of transformer core is composed and achieved results are incorporated into the proposed model in order to verify a correct operation of the circuit breaker and its reaction to different conditions. The verification of the symmetry of the magnetic field in residual current circuit breaker in Ansys Maxwell program is also a part of the study.

This work deals with modeling of progression of dielectric variables and mixture formulas for solution of properties of composite materials in dependency on frequency. Theoretical part of the work explains physical principles of polarisation mechanisms and influence on dielectric constant with changing temperature and frequency. In theoretical part processes inside the composite material, which is in electrical field are described. The work contains summary of mixture formulas and methods of their derivation. Program for use in education is a part of the work. It allows modelling of progression of dielectric variables in dependency on frequency and Cole-Cole circle diagram. In mixtures it allows modelling of frequency dependencies of dielectric constant in accordance to Maxwell's, Bőttcher's and Lichtenecker's mixture formulas.

ork tie together on first project, in which the was designed apparatus for tests wireless transmission energy. Antenna was synthesized and theoretically optimized for experimental operation, in which the will performed series measuring. In first part is practical description of realization proposal. It consists of circuital solution, proposal measuring workplace and mechanical construction with illustration photographs of arrangement. Second part includes results of performed measuring. These measuring will divided by three basic groups: in first group will by testing feature one’s antennae, in second group will series transmission measuring power gain, and in third group will photographed shape of field, and comparison with simple simulation finite difference method. Third part summarises results from measuring, and prepares consecutive balancing visualisation project, which is of thematic bent on chosen aspects theoretical hypothesis and effected experiments.

This thesis is dealing with optimization by using artificial intelligence of an induction machine rotor slot. The one optimized is commonly manufactured induction motor with simple deep bar rotor. Goal is to design an optimization method and achieve the highest possible value of efficiency and power factor of chosen machine. Work contains the parametric model construction in Ansys Maxwell software, the optimization algorithm assembly and its setup for desirable output, and processing of the results.

This thesis deals with the problem of the high-speed electrical machines. In the introduction summary of the high-speed machines are discussed. Induction machine with squirrel cage winding and solid rotor is chosen as suitable solution for given requirements. The multiple types of designs of the induction machines with solid rotor and problematic areas are discussed. Main part of this thesis is an electromagnetic design of the machine with respect to mechanical stress. The designed machine is analyzed with the use of finite element method in ANSYS Mechanical and Maxwell software.

The aim of this semester work is to analyze the losses of induction motor, according to their measure, use programs using the finite element method for the detection of the motor and the subsequent evaluation and comparison of the results obtained. The first part deals with the general AM, losses and measure their losses. The next section is very Lossmeasurement submitted asynchronous motors. The measured two machines have different characteristics in the sheet. The following section is calculating the losses using the finite element method using ANSYS Maxwell and RMXprt.The next part is the analysis of motor losses with a different number of rotor bars. This section is addressed to the models developed and validated by measuring the actual machine.