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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Early onset Anorexia Nervosa

Rose, Cynthia Beulah 06 1900 (has links)
Text in English / Two consecutive referrals of early onset (symptom onset at 11 years) anorexia nervosa (restricting sub-type) to an inpatient eating disorders unit in a psychiatric hospital, will be described. Within both cases, there was a history of sequential mother-daughter dieting prior to the daughter's onset of anorexic symptoms. This pattern will be viewed from the perspective of systemic theory, with reference to the cybernetic processes implicated in the onset and maintenance of symptoms. Structural systemic interpretations, in terms of exchangeable senses of self within the mother-daughter pairs, will also be considered. A brief comment will be made about the symmetry which underlies the choreography of anorexia nervosa when viewed from the perspective of communication theory. The implications for intervention will be addressed. In conclusion, the nature of the intergenerational transmission of disordered eating behaviours, will be considered with reference to the nature-nurture debate. / Clinical Psychology / M.A. (Clinical Psychology)
62

Modellierung des Oberschwingungsverhaltens von Windparks mit probabilistischen Ansätzen / Harmonic Behavior Modeling of Wind Farms Using Probabilistic Approaches

Malekian Boroujeni, Kaveh 19 July 2016 (has links) (PDF)
Oberschwingungen als ein Merkmal der Elektroenergiequalität gewinnen durch die starke Netzintegration leistungselektronisch geregelter Anlagen wie Windenergieanlagen und nichtlineare Lasten zunehmend an Bedeutung. Bestehende Normen entsprechen nicht den zukünftigen Erfordernissen des Elektroenergiesystems und bedürfen diesbezüglich einer Überarbeitung. In der Arbeit werden wesentliche Einflussfaktoren auf das Oberschwingungsverhalten von Windparks identifiziert, beschrieben und modelliert. Dabei wird der stochastische Charakter der Oberschwingungen mithilfe von probabilistischen Ansätzen erfasst. Des Weiteren wird ein neuer Ansatz zur Untersuchung der Wechselwirkung zwischen dem Windpark und dem vorgelagerten Netz entwickelt. Der Ansatz ermöglicht, die vom Windpark verursachte Änderung der Oberschwingungsspannung am Netzanschlusspunkt zu ermitteln. Diese Arbeit liefert einen Beitrag zur Verbesserung bestehender Normen für die Anbindung von Windparks. / Harmonics, as one of the power quality criteria, are increasingly gaining attention due to the progressive contribution of renewable energy resources and the application of the nonlinear load in the power system. Current standards do not conform to the future requirements of the power system, thus requiring a revision. In this work, main influence factors on the harmonic behavior of wind farms are identified, explained, and modelled. Thereby, the stochastic nature of harmonics is taken into account using probabilistic approaches. Moreover, a novel approach is developed to investigate the interaction between the wind farm and the upstream grid. With the aid of this approach, it is possible to determine the voltage change caused by the wind farm at the point of connection. This work contributes to improve the existing standards for the connection of wind farms.
63

Material characterisation, phase transitions, electrochemical properties and possible fuel cell applications of Nd₂₋ₓPrₓCuO₄ and Nd2-x-y LayPrₓCuO₄ systems

Patabendige, Chami N. K. January 2012 (has links)
The well-known lanthanide cuprates exist in two principal forms, T and T´, which behave as p-type and n-type conductors, respectively. In order to understand the structural properties and crystal chemistry from the T to T´ phase, the Nd₁.₈₋ₓLaₓPr₀.₂CuO₄ (NLPCO) system was studied varying the La substitution ratio (0≤x≤1.8) and then characterised using high temperature X-ray powder diffraction. From analysis of the X-ray diffraction patterns obtained at room temperature, there are clearly five distinguishable regions for the NLPCO system. They are, (1) monophasic T´ solid–solution (2) two phase mixture T´ + T´´ (3) monophasic T´´solid–solution (4) two phase mixture T´´ + O and finally (5) monophasic O phase solid–solution. The T´´ form has previously been suggested as an ordered form of T´; however here we show via high temperature X-ray diffraction studies that it is a non-transformable metastable phase formed on quenching of the T phase via an orthorhombically distorted variant. Also neutron diffraction and selected area electron diffraction (SAED) studies confirmed that the T ´´phase is 4- fold Cu coordinated. The structural, magnetic and electrical properties of this NLPCO series have been investigated for the selected compositions using X-ray diffraction, magnetization measurements, thermal analysis and conductivity measurements. The aim of the second half of this work was to discover the basic high temperature electrical characteristics of Nd₂₋ₓPrₓCuO₄ and investigate how this matches with those required for components on the SOFC cathode side to identify which dopant level shows highest conductivity and whether it is stable at different temperatures. The idea was to make a new concept in SOFC cathodes and current collector development, using n-type conductors instead of p- type conductors and to try to produce a high conductivity material which is stable under the chemical and thermal stresses that exist while under load that can be used in cathode or current collector applications. The Nd₂₋ₓPrₓCuO₄ (NPCO) series has been studied over a range of dopant levels (x=0.15 - 0.25) and maximum conductivity of 86.7 Scm⁻¹ has been obtained for the composition where x = 0.25. Also NPCO shows n-type semiconductor behaviour which gives operational advantages when operating at mild oxygen deficiency. AC impedance studies have been carried out on symmetrical cells to investigate the performance of NPCO as a cathode material. These studies mainly focused on polarization resistance and the activation energies of the cells. Low Rp values and low activation energies are obtained for a composite cathode compared to pure cathode material. Two configurations of NPCO as cathode materials were tested, pre-fired and in-siu fired. Pre-fired NPCO exhibited better performance than in-situ fired NPCO. Both in-situ and pre-fired current collecting NPCO still showed lowest activation energies which suggest good catalytic activity. From all of these studies, it is evident that the praseodymium doped neodymium cuprate material shows considerable promise as a potential cathode material for solid oxide fuel cell applications.
64

A virtual RSNS direction finding antenna system

Chen, Jui-Chun 12 1900 (has links)
Approved for public release; distribution in unlimited. / In this thesis, a performance analysis and improvement of a phase sampling interferometer antenna system based on the Robust Symmetrical Number System (RSNS) in the presence of noise is investigated. Previous works have shown that the RSNS-based DF technique can provide high bearing resolution with a minimum number of antenna elements. However, the previous experimental data showed significant deviation from the theoretical results expected due to imperfections, errors, and noise. Therefore, an additive Gaussian noise model of RSNS-based DF was established and simulated. Simulation results show that the presence of noise distorts the signal amplitudes used in the RSNS processor and causes degradation of the angle-ofarrival estimates. A performance analysis was undertaken by first introducing the quadrature modulation configuration into RSNS-based DF system, which provided a digital antenna approach for more flexibility in the signal processing. With a digital approach, variable resolution signal preprocessing can be employed, using a virtual channel concept. The virtual channel concept changes moduli values without changing the actual physical antenna element spacing. This attractive property allows the RSNS algorithm to be implemented into existing antenna arrays and only requires modifying the antenna signal processor. Computer simulation results showed that the proposed method can successfully improve the system performance and also mitigate the effects of noise. / Captain, Taiwan Army
65

Controvérsias em torno das práticas e terapias de cura: a epidemia de cólera-morbus em Pernambuco (1855) / Controversies regarding practices and healing therapies: the epidemic of cholera-morbus in Pernambuco (1855)

Santos, Luciana dos 22 March 2013 (has links)
O trabalho focaliza as controvérsias que se seguem ao evento da epidemia de cóleramorbus deflagrada na província de Pernambuco no ano de 1855, em torno de práticas e terapias que foram mobilizadas no combate à moléstia. O fio condutor da análise são os embates que se estabeleceram entre a medicina acadêmica e outras formas terapêuticas - particularmente de homeopatas, leigos, negros e índios. Adicionalmente, o trabalho procura pontos de intersecção entre a emergência de um projeto moderno de medicina e a religião, acompanhando a reflexão e a prática produzidas pelos missionários capuchinhos italianos sobre a epidemia. / The work focuses on the controversy following the event of the epidemic of choleramorbus triggered in the province of Pernambuco in the year 1855, around practices and therapies that have been mobilized to fight the disease. The guiding thread of the analysis are the shocks that have been established between academic medicine and other therapeutic methods - particularly of homeopaths, lay people, blacks and indians. Additionally, the work searches points of intersection between the emergence of a modern project of medicine and religion, accompanying the reflection and practice produced by italian capuchin missionaries on the epidemic.
66

Vida de babá: reflexões acerca das vivências profissionais à luz da psicologia analítica / Life of nanny: reflections about the professional experiences in focus of analytical psychology

Baltazar, Talita Rocha 21 October 2011 (has links)
Made available in DSpace on 2016-04-28T20:37:54Z (GMT). No. of bitstreams: 1 Talita Rocha Baltazar.pdf: 975265 bytes, checksum: 13147feef062e4f6f5d939bdb2fc192f (MD5) Previous issue date: 2011-10-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This research is characterized by the qualitative methodological approach and the objective is to develop a reflection about the particularities of the daily work experiences of nannies, in focus of analytical psychology, considering historical and social aspects. The work is a human experience that highlights the intersection of collective and individual nature, which is encouraged throughout the individuation. From the concept of work and the ancestry of the profession in Brazil, which denotes its cultural complex, we construct a reflection approaching the daily work of nannies today and some considerations about their professional persona. We note that the centrality of work is a characteristic of the profession, influencing the lives of workers in how they invest energy and dedication in the personal and family context. This occurs mainly among workers who live in the residence of work, which makes the boundary between public and private spheres almost nonexistent, which may favor the rigidity of the professional persona. The professional role of the nanny is related to parental functions such as care, educate, give affection, attention and love, through a substitutive fraternal relationship, which makes her supporting of familiar life. In this sense, she coordinates archetypal elements of maternal and paternal, of eros and power, in their daily assignments. The coordination of these elements stems from the psychological baggage of professional and express your personal directory about the symmetric and asymmetric relations. This dynamic is manifested in the relationship between the worker, child and parents, setting up a triangulation, in which the nanny must pass, and the more good it does, more integrate will be the experience of his professional persona. Thus, it becomes relevant to the creation of a specialized space, group and/or individual, in which daily experiences can be shared in order to increase consciousness of workers about their professional role, and also to propitiate the development of symbolic language, which can facilitate the individuation / Esta pesquisa caracteriza-se pelo enfoque metodológico qualitativo e tem como objetivo conhecer as particularidades do cotidiano de trabalho das babás, no intuito de elaborar uma reflexão acerca dessas vivências à luz da psicologia analítica, considerando aspectos históricos e sociais. O trabalho é uma experiência humana que evidencia a intersecção entre a sua natureza coletiva e individual, que é dinamizada ao longo do processo de individuação. A partir do conceito de trabalho, e da ancestralidade da profissão no Brasil, que denota o seu complexo cultural, construímos uma reflexão abordando o cotidiano de trabalho das babás na atualidade e algumas considerações sobre sua persona profissional. Observamos que a centralidade do trabalho é uma característica da profissão, que influencia a vida das trabalhadoras no modo como investem energia e dedicação no âmbito pessoal e familiar. Isso acontece, principalmente, entre as trabalhadoras que moram na residência de trabalho, o que torna a fronteira entre os âmbitos público e privado quase inexistente, podendo favorecer a rigidez da persona profissional. O papel profissional da babá está relacionado a funções parentais como cuidar, educar, dar carinho, atenção e amor, por meio de uma relação substitutiva fraternal, que a torna coadjuvante da vida familiar. Nesse sentido, ela coordena elementos arquetípicos maternos e paternos, de eros e poder, em suas atribuições cotidianas. A coordenação desses elementos decorre da bagagem psicológica da profissional e expressa o seu repertório pessoal sobre as relações simétricas e assimétricas. Essa dinâmica é manifestada no relacionamento entre a trabalhadora, a criança e os pais, configurando uma triangulação, na qual a babá precisa transitar e, quanto mais bem ela o fizer, mais integrada será a vivência de sua persona profissional. Assim, torna-se relevante a criação de um espaço especializado, grupal e/ou individual, no qual experiências cotidianas possam ser compartilhadas, a fim de ampliar a consciência das trabalhadoras acerca do seu papel profissional e, também, de propiciar o desenvolvimento da linguagem simbólica, o que pode favorecer o processo de individuação
67

Development of spinel-based electrode supports for solid oxide fuel cells

Stefan, Elena January 2013 (has links)
The high temperature oxidation of ferritic stainless steel interconnects results in chromium poisoning of the solid oxide fuel cell (SOFC) electrodes, which is a limiting factor for their utilisation as SOFC interconnects. Chromium-rich spinel materials were studied as electrode supports that would be situated at the interface between interconnect and electrode, in order to reduce the effect of chromium poisoning of the electrodes. The main goal of this thesis was to find chromium-rich spinel materials with good electrical conductivity (σ ≥ 0.1 S∙cm⁻¹) in air and reducing atmosphere, chemically and mechanically stable in SOFC testing conditions. The structure and properties of newly formulated chromium-rich spinels, such as Mn₁₊ₓCr₂₋ₓO₄ (x = 0, 0.5), MnFeₓCr₂₋ₓO₄ (x = 0.1, 1), MgMnCrO₄, MnLiₓCr₂₋ₓO₄ (x = 0.1) and MgMₓCr₂₋ₓO₄, (M = Li, Mg, Ti, Fe, Cu, Ga) were studied aiming at their application as electrode support material for solid oxide fuel cells. Cation distributions were determined by Rietveld refinement from X-ray diffraction (XRD), within the limits of XRD precision and correlated with electrical properties determined experimentally. The chemical stability in reducing conditions was studied and the reduction effects upon materials were evaluated by XRD phase analysis and microstructure analysis. It was found that MnMₓCr₂₋ₓO₄ materials have a limited stability to reduction, only MnCr₂O₄ proved to have good stability when reduced, with negative influence for its p-type semiconductor conductivity. Even though MnFeCrO₄ had limited stability to reduction, in reducing conditions the conductivity changed from p-type to n-type semiconductor. A similar behaviour to reduction was observed for MgFeCrO₄. Also the mechanical and chemical compatibility of some spinels with YSZ was studied in terms of thermal expansion coefficient (TEC/K⁻¹), sintering step and possible chemical reactions. Lithium titanate spinels, starting with LiCrTiO₄, were investigated in terms of structure, properties and spinel - ramsdellite phase transition temperature also with the purpose of new material development. For these materials positive results were obtained in conductivity and chemical stability in reducing conditions. The performance of MnFeCrO₄ and MgFeCrO₄ as electrode support materials was investigated when used alone or impregnated with (La₀.₇₅Sr₀.₂₅)₀.₉₇Cr₀.₅Mn₀.₅O₃, La₀.₈Sr₀.₂FeO₃, Ce₀.₉Gd₀.₁O₂, CeO₂ or Pd. Composite anodes for SOFC were prepared by aqueous infiltration of nitrate salts into porous MnFeCrO₄ and MgFeCrO₄ scaffolds and studied by electrochemical impedance spectroscopy (EIS) in symmetrical cell configuration. The performance of the composite anodes was evaluated in humidified 5%H₂/Ar in order to understand their stability and performance at 850 °C or lower temperature with respect to the porous substrates. It was found that all the impregnated phases adhere very well to the spinel and considerably enhance performance and stability to a level required for SOFC applications. An interesting next step in this work would be to apply such spinel materials on steel interconnects, integrate them into testing SOFC devices and evaluate their effect upon chromium poisoning of the electrodes.
68

Controvérsias em torno das práticas e terapias de cura: a epidemia de cólera-morbus em Pernambuco (1855) / Controversies regarding practices and healing therapies: the epidemic of cholera-morbus in Pernambuco (1855)

Luciana dos Santos 22 March 2013 (has links)
O trabalho focaliza as controvérsias que se seguem ao evento da epidemia de cóleramorbus deflagrada na província de Pernambuco no ano de 1855, em torno de práticas e terapias que foram mobilizadas no combate à moléstia. O fio condutor da análise são os embates que se estabeleceram entre a medicina acadêmica e outras formas terapêuticas - particularmente de homeopatas, leigos, negros e índios. Adicionalmente, o trabalho procura pontos de intersecção entre a emergência de um projeto moderno de medicina e a religião, acompanhando a reflexão e a prática produzidas pelos missionários capuchinhos italianos sobre a epidemia. / The work focuses on the controversy following the event of the epidemic of choleramorbus triggered in the province of Pernambuco in the year 1855, around practices and therapies that have been mobilized to fight the disease. The guiding thread of the analysis are the shocks that have been established between academic medicine and other therapeutic methods - particularly of homeopaths, lay people, blacks and indians. Additionally, the work searches points of intersection between the emergence of a modern project of medicine and religion, accompanying the reflection and practice produced by italian capuchin missionaries on the epidemic.
69

Contribution des moyens de production dispersés aux courants de défaut. Modélisation des moyens de production et algorithmes de détection de défaut. / Fault current contribution from Distributed Generators (DGs). Modelling of DGs and fault detection algorithms.

Le, Trung Dung 28 February 2014 (has links)
Les travaux de la thèse se focalisent sur la protection des réseaux de distribution HTA en présence des générateurs distribués (éoliennes, fermes solaires,...). Dans un premier temps, un état de l’art a été réalisé sur les comportements des générateurs en creux de tension, leurs impacts sur le système de protection et les pistes de solution proposées pour y remédier. L’étape suivante est la mise au point d’algorithmes directionnels de détection de défauts, sans mesure de tension. Ces algorithmes s’appuient sur la décomposition en composantes symétriques des courants mesurés. Ces relais doivent empêcher le déclenchement intempestif de protections de surintensité dû au courant de défaut provenant des générateurs distribués. Ils sont moins coûteux par rapport à ceux traditionnels car les capteurs de tension, qui sont indispensables pour ces derniers, peuvent être enlevés. Après détection d’un défaut sur critère de seuil simple (max de I ou max de I résiduel), la direction est évaluée à l’aide d’un algorithme en delta basé sur les rapports courants inverse-homopolaire ou inverse-direct, selon le type de défaut (monophasé ou biphasé). En se basant sur ces rapports, un classifieur SVM (Support Vector Machines), entrainé préalablement à partir des simulations, donne ensuite l’estimation de la direction du défaut (amont ou aval par rapport au relais). La bonne performance de ces algorithmes a été montrée dans la thèse pour différents paramètres du réseau et en présence de différents types de générateurs. Le développement de tels algorithmes favorise la mise en œuvre des protections en réseau, qui pourraient être installées dans les futurs Smart Grids. / This research focuses on the protection of MV distribution networks with Distributed Generators (DGs), such as wind farms or photovoltaic farms, etc. First, the state of art is carried out on fault behaviour of DGs, their impacts on protection system and the mitigation solutions. Next, algorithms are developed for directional relays without voltage sensors. Based on the symmetrical component method, these algorithms help the overcurrent protections to avoid the false tripping issue due to fault contribution of DGs. With the suppression of voltage sensors, such directional relays become cheaper in comparison with the traditional ones. Following the fault detection (the phase or residual current reaches the pick-up value) and depending on fault type (line-to-ground or line-to-line fault), the ratios between the variation (before and during fault) of negative-zero sequence or negative-positive sequence currents are calculated. From these ratios, a SVM (Support Vector Machines) classifier estimates the fault direction (upstream or downstream the detector). The classifier is trained beforehand from transient simulations. This survey shows good performances of the directional algorithms with different network parameters and different kinds of DGs. Such algorithms could be implemented in protections along the feeders in the future smart grids.
70

Mer än valkyrior : En omtolkning av vikingatidens feminina figuriner / More than Valkyries : A re-interpretation of Viking Age Female Figurines

Wihlborg, Julia January 2019 (has links)
Figurines with a human shape have been created in almost every culture all throughout human history. In this thesis one such group of figurines is under investigation, Viking age female figurines. These figurines are most often interpreted as representations of the Valkyries – shieldmaidens of the god Odin – or as the goddess Fröja. Interpretations made through comparative studies with the medieval written sources. However, these interpretations always privileges some attributes of the figurines over others, creating simplified and general interpretations. The purpose of this thesis is to (re)interpret the figurines beyond the concept of representation, and instead focus on what the figurines, through their various attributes (size, motive, material), do and how they influence human actions. This is realized through the creation of a catalogue of all currently known female figurines from the Viking age (53 pieces), a correspondence analysis and through the use of symmetrical archaeology and embodiment theory. The result shows that the most important attributes of the figurines is their physical bodies, through which they can interact with the world, trigger emotions, hold memory, become animated and be part of the performative practice of upholding individual identity as well as upholding both the social- and cosmological worlds.

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