Tesis sobre el tema "Magnetisation M(T,H)"

Dans la recherche de matériaux magnétoélectriques (ME) présentant des performances ME élevées, nous étudions dans cette thèse certains mécanismes fondamentaux qui conduit au renforcement du couplage magnéto-élastique dans les composites MEs. Notre étude porte sur les composites particulaires 0-3 composés de phase magnétostrictive (MS) de CFO imbibée dans des matrices ferroélectriques (FE) suivantes : à base de Pb PZT, PMNPT et leur alternative sans plomb KNN et BTO. Nous démontrons que la technique Laser Heated Pedestal Growth (LHPG) peut être utilisé pour synthétiser des échantillons massives avec une microstructure texturée prononcée entre les phases FE et MS. Scanning electron microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS) et X-ray diffraction (XRD) sont utilisés pour caractériser systématiquement l’orientation des grains, la taille des grains and la qualité d’interface entre les différentes phases citées ci-avant. Une étude systématique par le biais de la spectroscopie Raman, les mesures de magnétisation M (H,T) et de chaleur spécifique C(T,H) nous ont permis de sonder le couplage magnéto-élastique directement dans les échantillons MEs. En combinant les analyses des données structurales et thermodynamiques précédentes, cela montre que la structure avec une texture prononcée dans les échantillons synthétisés par LHPG conduit à une forte augmentation de la réponse magnéto-élastique. Nous soutenons que ce résultat est très prometteur pour la conception des matériaux ME. Enfin, nous suggérons que l'étude de la chaleur spécifique précédent offre une sonde sans contact pour étudier le couplage spin-réseau de manière intrinsèque dans une large gamme de matériaux ME y compris les multiférroiques
In the search for magnetoelectric (ME) materials with enhanced ME performances, in the present thesis we investigate some fundamental mechanisms leading to an enhanced magnetoelastic coupling in artificial ME composites. We focus on 0-3 particulate composites made of a magnetostrictive (MS) phase CFO embedded in the following ferroelectric (FE) matrices: Pb-based PZT, PMNPT and alternative lead-free KNN and BTO. We demonstrate that the laser heated pedestal growth (LHPG) technique can be successfully used to grow high-quality bulk samples exhibiting a pronounced textured microstructure between the FE and MS phases. Scanning electron microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS) and X-ray diffraction (XRD) were used to characterise systematically grain orientation, grain size and quality of the interface between the FE and MS phases. A systematic study by means of Raman spectroscopy, magnetisation M(T,H) and field-dependent specific heat C(T,H) measurements enabled us to probe directly the magnetoelastic coupling in the ME samples. The combined analysis of the above structural and thermodynamic data consistently shows that the pronounced textured structure of the LHPG samples leads to an impressive enhancement of the magnetoelastic response. We argue that this result is very promising for ME material design. We finally propose that the above specific heat study offers a contactless probe to investigate the intrinsic spin-lattice coupling in a wide range of ME materials including multiferroics

Mythic is an animated family series that will collide the worlds of the beloved Disney style musical feature, with everyday children’s programming. Based on 8 public domain works by Hans Christian Andersen, the series will follow Princess Viv, Farmhand Penelope, Pit-Pocket Leina, and a hopelessly romantic Prince Agner, as they travel through magical kingdoms in hopes of retrieving 8 mythical relics. Together, the four will learn about the meaning of love, the danger of greed, and the joy of being selfless as they fight to keep Leina from becoming a true villain.

We present the effective temperatures (T-eff), metallicities, and colours in Sloan Digital Sky Survey (SDSS), Two Micron All Sky Survey, and Wide-field Infrared Survey Explorer filters, of a sample of 3834 late-K and early-M dwarfs selected from the SDSS Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectroscopic survey ASPCAP (APOGEE Stellar Parameters and Chemical Abundances Pipeline) catalogue. We confirm that ASPCAP T-eff values between 3550 < T-eff < 4200 K are accurate to similar to 100 K compared to interferometric T-eff values. In that same T-eff range, ASPCAP metallicities are accurate to 0.18 dex between -1.0 <[M/H]< 0.2. For these cool dwarfs, nearly every colour is sensitive to both T-eff and metallicity. Notably, we find that g - r is not a good indicator of metallicity for near-solar metallicity early-M dwarfs. We confirm that J - K-S colour is strongly dependent on metallicity, and find that W1 - W2 colour is a promising metallicity indicator. Comparison of the late-K and early-M dwarf colours, metallicities, and T-eff to those from three different model grids shows reasonable agreement in r - z and J - K-S colours, but poor agreement in u - g, g - r, and W1 - W2. Comparison of the metallicities of the KM dwarf sample to those from previous colour-metallicity relations reveals a lack of consensus in photometric metallicity indicators for late-K and early-M dwarfs. We also present empirical relations for T-eff as a function of r - z colour combined with either [M/H] or W1 - W2 colour, and for [M/H] as a function of r - z and W1 - W2 colour. These relations yield T-eff to similar to 100 K and [M/H] to similar to 0.18 dex precision with colours alone, for T-eff in the range of 3550-4200 K and [M/H] in the range of -0.5-0.2.

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O presente trabalho apresenta um estudo de desempenho de um sistema h?brido fotovoltaico/t?rmico (sistema PVT), comparando-o com um sistema fotovoltaico (sistema PV). Foi analisada a pot?ncia el?trica e t?rmica, a efici?ncia e a energia produzida pelos sistemas, correlacionando ? influ?ncia da temperatura do m?dulo PV e a efici?ncia el?trica dos sistemas. O m?dulo fotovoltaico (PV) utilizado foi o MSX 77 da marca SOLAREX, composto por c?lulas solares policristalinas, cuja pot?ncia de pico ? de 77 Watts. O sistema PVT analisado foi do tipo PVT-l?quido, composto pelo m?dulo PV MSX77 e um coletor solar plano do tipo placa fabricado em acr?lico, a alimenta??o de ?gua do coletor foi do tipo for?ada por gravidade e com sistema aberto. Para determinar as curvas caracter?sticas do m?dulo PV e por consequ?ncia a pot?ncia el?trica m?xima gerada, foi desenvolvido um banco de carga formado por resistores de pot?ncia. A pot?ncia t?rmica foi quantificada aferindo a vaz?o da ?gua que alimentava o coletor e a diferen?a de temperatura da ?gua de entrada e sa?da. Com as pot?ncias e a radia??o incidente sobre os sistemas, foram determinadas as efici?ncias. A m?xima efici?ncia el?trica informada pelo fabricante do m?dulo PV ? de 10,8 %, contudo, em condi??es reais de opera??o, a m?xima efici?ncia do m?dulo PV foi de 8,46 %. No sistema PVT, o m?dulo PV apresentou uma efici?ncia m?xima de aproximadamente 7,8 % no ponto de m?xima pot?ncia gerada. A efici?ncia m?dia do sistema t?rmico foi na ordem de 42,5 %. O sistema PVT proporcionou a redu??o da temperatura do m?dulo PV, aumentando a efici?ncia de gera??o el?trica, proporcionando um aumento na ordem dos 6,9 % na energia el?trica m?dia di?ria. O sistema PVT al?m de proporcionar um aumento de energia el?trica, ainda fornece energia t?rmica com uma efici?ncia superior ? el?trica. A ?gua aquecida pode ser utilizada para alimentar sistemas de aquecimento de ?gua para banho, contribuindo para redu??o do consumo de energia el?trica de uma resid?ncia.
The present dissertation presents a performance study of a hybrid photovoltaic / thermal system (PVT system), comparing it with a photovoltaic system (photovoltaic system). The electrical and thermal power, efficiency and energy produced by the systems were analyzed, correlating the influence of the temperature of the photovoltaic module and the electrical efficiency of the systems. The photovoltaic (PV) module used was the MSX 77 of the brand SOLAREX, composed of polycrystalline solar cells, whose peak power is 77 Watts. The PVT system analyzed was of the PVT-liquid type, composed of the MSX77 photovoltaic module and a flat plate type solar collector made of acrylic, the water supply of the manifold was forced by gravity and with open system. To determine the characteristic curves of the PV module and consequently the maximum electric power generated, a load bank formed by power resistors was developed. The thermal power was quantified by measuring the flow of the water that fed the collector and the difference in temperature of the incoming and outgoing water. With the powers and the radiation incident on the systems, the efficiencies were determined. The maximum electrical efficiency reported by the manufacturer of the PV module is 10.8 %, however, under actual operating conditions, the maximum efficiency of the PV module was 8.46 %. In the PVT system, the PV module showed a maximum efficiency of approximately 7.8 % at the point of maximum power generated. The average efficiency of the thermal system was around 42.5 %. The PVT system provided a reduction in the temperature of the PV module, increasing the efficiency of electric generation, providing an increase in the order of 6.9 % in the average daily electric energy. The PVT system, besides providing an increase in electrical energy, still provides thermal energy with a higher efficiency than electric. The heated water can be used to power water heating systems for bathing, contributing to reduce the consumption of electric energy of a residence.

The study of hydro-mechanical (HM) coupled problems in different areas of civil, environmental or petroleum engineering is common in literature, but the effect of a thermal field by means of the heat transport by a fluid through the discontinuities is not considered in the current tools of analysis, in which the effect of the temperature gradient between the fluids flowing through the discontinuities and the in-situ thermal state are not considered. In geomechanics modeling it is important to distinguish between the hydraulic behavior of the porous medium and that of the discontinuities, together generating a double-permeability system where the discontinuities establish preferential flow paths. Because of high hydraulic velocities in the discontinuities, the advection (transport) may be the dominant heat transfer mode. Thus, the study of THM coupled processes with thermal advection in discontinuities is important in problems with a certain degree of coupling between the mechanical, hydraulic and thermal fields, and in which the hydraulic flow transports heat through the discontinuities. It is important to establish a numerical model to study the advection phenomena that differentiates the discontinuity network and the porous medium contributions. In this context, this thesis focuses on the study, formulation, numerical implementation and verification of a THM fully-coupled model with large advection, able to reproduce the advective behaviour that occurs in discontinuities, in which heat is transported by the fluid. This numerical approach is carried out using the finite element method (FEM) with zero-thickness interface elements to represent the discontinuities, and assuming saturated conditions and a single incompressible fluid (constant density). It is also assumed that all the non-linear behaviour occurs at the interface elements by means of an elasto-plastic constitutive law based on fracture mechanics. Additionally, the numerical approach to the thermal advection presents a singularity in comparison with pure diffusive problems. If the fluid velocities are low, the numerical formulation can be made by traditional FEM (Galerkin). However, when the fluid velocities are high and the advection dominates the problem, the standard Galerkin weighting leads to oscillatory results, and the advective term requires a special treatment to stabilize the numerical solution. A review of different methodologies to solve the large advective problem is presented, selecting the Streamline Upwind Petrov-Galerkin method to solve the steady-state. For transient states, this thesis starts with the study of the existing explicit Characteristic Galerkin Method (CGM), which studies the advective phenomena in a Lagrangian manner, following the particle (or heat) with the fluid by setting a moving coordinate system that depends on the fluid velocity and its position in time. Then the implicit CGM is developed, and finally a new variation is proposed adding a parameter alpha that allows determining different temporal derivative positions of the advective volume, leading to the alpha-Implicit CGM, that allows to obtain stable solutions if the Courant condition is fulfilled. In order to verify the THM model with large advection for continuum medium and zero-thickness interfaces, several simple verification examples are presented. Finally, an application to hydraulic fracture (HF) with a single fracture in 2-D is introduced in order to understand the thermal mechanisms that occur in HF problems and how they affect the mechanical and hydraulic fields. In addition, these results are compared with those obtained using the HM model, where the thermal field is not considered. Finally, in order to improve the computational capacities of the FEM code, its parallelization has performed following a subdomain decomposition strategy, leading to a substantial improvement in the speed of the calculations and showing a good degree of scalability.
El estudio de problemas hydro-mecánicos (HM) acoplados en diferentes áreas de ingeniería civil, ambiental o del petróleo es común en la literatura, pero los efectos térmicos del fluido transportando calor a través de fracturas o discontinuidades no se considera en las actuales herramientas de análisis, en las cuales el efecto de la diferencia de temperatura entre el fluido inyectado a través de las discontinuidades y la del medio in situ no se tiene en cuenta. No obstante, en algunos problemas geomecánicos los comportamientos mecánico, hidráulico y térmico del medio poroso fracturado pueden aparecer acoplados con fuertes interacciones entre ellos. En modelación geomecánica es importante distinguir el comportamiento hidráulico del medio poroso del de las discontinuidades, ambas generando un sistema de doble permeabilidad en el cual el medio poroso proporciona una pequeña permeabilidad al sistema, mientras que las discontinuidades establecen caminos preferentes y proporcionan gran permeabilidad al mismo. Debido a las elevadas velocidades de fluido que se pueden desarrollar en las discontinuidades, la advección (transporte) puede ser el modo dominante de transferencia de calor. Por ello, el estudio de procesos THM acoplados con advección térmica en discontinuidades es importante en problemas con un cierto grado de acoplamiento entre los campos mecánico, hidráulico y térmico, y en los cuales el flujo hidráulico puede transportar calor a gran velocidad a través de las discontinuidades. Por ello, es importante establecer un modelo numérico para estudiar el fenómeno advectivo que diferencie la contribución de la red de discontinuidades de la del medio continuo poroso. En este contexto, esta tesis está enfocada en el estudio, formulación, implementación numérica y verificación de un modelo THM acoplado monolítico con advección dominante que sea capaz de reproducir el comportamiento advectivo que ocurre en discontinuidades o fracturas, en las cuales el fluido transporta calor. Este estudio se lleva a cabo en el contexto geomecánico de un medio poroso fracturado, empleando el método de los elementos finitos (FEM) con elementos junta de espesor nulo para representar las discontinuidades o fracturas, suponiendo condiciones saturadas, un único fluido incompresible (con densidad constante) y pequeñas deformaciones. También se supone que todo el comportamiento no lineal se desarrolla en las juntas mediante el uso de una ley constitutiva elasto-plástica basada en mecánica de fractura, mientras que el medio continuo poroso se supone de comportamiento poro-elástico. Adicionalmente, la solución numérica del problema térmico advectivo presenta singularidades con respecto a los problemas de difusión pura. Cuando las velocidades del fluido son bajas, la formulación numérica se puede llevar a cabo mediante Elementos Finitos tradicionales (Galerkin). No obstante, cuando las velocidades del fluido son suficientemente elevadas y la advección domina el problema el método estándar de Galerkin conduce a resultados oscilantes, por lo que el término advectivo requiere un tratamiento especial para estabilizar la solución numérica. En este contexto, se presenta una revisión de diferentes metodologías para resolver el problema de advección dominante, seleccionando el método Streamline Upwind Petrov-Galerkin (SUPG) para resolver el problema en régimen permanente, un método bien conocido que conduce a soluciones estables con advección dominante. Para el régimen transitorio esta tesis empieza con el estudio del método de Características Galerkin explícito, un método existente en el que el fenómeno advectivo se estudia de modo Lagrangiano, siguiendo la partícula (o calor) con el movimiento del fluido, y estableciendo para ello un sistema de coordenadas móvil que depende de la velocidad del fluido y de su posición en el tiempo. Seguidamente se desarrolla la forma implícita de este método, y finalmente se propone una nueva variación del método, añadiendo un parámetro 𝛼�𝛼� que permite determinar diferentes posiciones de las derivadas temporales del volumen advectivo, concluyendo en el nuevo 𝛼�𝛼�-Implicit Characteristic Galerkin Method. Con esta nueva metodología se estabiliza el problema de gran advección en régimen transitorio si se cumple la condición de Courant. Con el fin de verificar el modelo THM monolítico acoplado con advección dominante se presentan diversos ejemplos de verificación, tanto para medio continuo poroso como para elementos junta de espesor nulo. Finalmente, se presenta un caso de aplicación a fractura hidráulica (HF), llevando a cabo el análisis numérico de una sola fractura en 2-D con el objetivo de entender los mecanismos térmicos que ocurren en problemas de HF y como éstos afectan sobre los comportamientos mecánico e hidráulico. Además, los resultados de la modelación se comparan con los obtenidos empleando un modelo HM, en el cual no se consideran efectos térmicos. Adicionalmente, con el objetivo de mejorar la eficiencia computacional del código de Elementos Finitos, se ha llevado a cabo la paralelización del mismo mediante una estrategia de partición de subdominios, resultando en una mejora sustancial de la velocidad de los cálculos y mostrando una buena escalabilidad de los mismos.

L'etude numerique des mouvements de la phase fluide et de leur interaction sur le processus de croissance de monocristaux de cdte par t. H. M. Est effectuee par une methode de volumes finis. Nous avons integre a la convection thermique l'aspect convectif d'origine solutal. Dans les conditions aux limites, deux types de frontieres actives (interfaces fluide-solide) et non-actives (parois de l'ampoule) sont integres. Apres avoir determine les grandeurs caracteristiques adimensionnelles, des resultats sont presentes en configuration simplifiee de la zone fluide delimitee par des interfaces planes et rigides dans une premiere partie et dans l'ampoule entiere dans une seconde partie. Nous mettons alors en evidence des phenomenes convectifs oscillatoires periodiques

Pour étudier l'influence de la gravité sur la croissance par T. H. M. Du semi-conducteur CdTe dopé indium (programme EURECA), nous avons effectué une analyse comparative d'expérience spatiales et terrestres, complétée par une simulation numérique de l'hydrodynamique de la phase fluide utilisant un code 3D. Notre deuxième objectif a été de prépérer des monocristaux de CdTe dopé vanadium par la technique Bridgman présentant de bonnes propriérés photoréfractives. Pour une meilleure compréhension du mécanisme de l'effet photoréfractif, les matériaux ont été caractérisés par R. P. E. , D. C. M. Et P. I. C. T. S. Afin de déterminer le degré de valence de V et la signature des niveaux vanadium dans la bande interdite. Des mesures optiques (absorption, photoconductivité. . . ) et d'effet photoréfractif ont été effectuées. Enfin, pour évaluer la pertinence spatiale de cette croissance, nous avons étudié par simulation numérique l'influence de la gravité sur la configuration hydrodynamique de la phase fluide.

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Considerando-se a import?ncia dos c?nones da literatura e as dificuldades encontradas pelos professores em geral do Ensino B?sico para promover a leitura desses textos, a pesquisa, tendo como base a Est?tica da Recep??o e a Sociologia da Leitura, pretende fundamentar uma proposta de pr?tica de ensino da leitura realizada atrav?s de um projeto desenvolvido em uma turma da primeira s?rie do Ensino M?dio. O Projeto parte da literatura n?o-can?nica, o g?nero policial, para chegar ? literatura can?nica. Com essa pr?tica, a pesquisa pretende discutir a possibilidade de desenvolver o gosto pela leitura de textos consagrados, a partir de obras n?o-canonizadas, cujos elementos estruturais geralmente s?o organizados de forma a facilitar a leitura, o que tamb?m atrai leitores iniciantes. Imp?e-se, portanto, uma revis?o te?rica relacionada ? leitura da literatura na escola, destacando a import?ncia dessa institui??o e dos professores na forma??o do leitor de literatura. Recuperam-se tamb?m estudos a respeito do c?none liter?rio, que devem contribuir para o entendimento dos sistemas liter?rios. O g?nero policial, desde a sua forma??o at? os dias de hoje, tamb?m ? analisado, tendo em vista as suas caracter?sticas, os autores precursores, as novas modalidades e o efeito sobre os leitores. A pesquisa de cunho bibliogr?fico volta-se, ent?o, para a pesquisa de campo, em que se executa o projeto de ensino elaborado a partir da conjun??o dos elementos te?ricos e se analisam os resultados obtidos, no que se refere ? forma??o de leitores de literatura

Studien undersöker invånare och verksammas upplevelser av ett, enligt en rapport frånunderrättelseenheten, utsatt bostadsområde i Västerås. För att besvara frågeställningen har vigenomfört 14 intervjuer varav 5 var semistrukturerade och resterande var ostrukturerade. Vihar även genomfört 6 observationer, där samtliga var icke deltagande observationer. Dåmålsättningen var att undersöka så förutsättningslöst som möjligt har vi använt oss av BarneyGlasers variant av grundad teori som metodologiskt angreppssätt. Tidigare forskning som vibelyser är delade i tre teman: Segregation, familjestrukturer och sysselsättning. En teorisom är grundad i data presenteras i resultatdelen och beskriver det som sker i Bäckby.Studiens teoretiska referensramar är Erving Goffmans teori om stigma, Howard. S. Beckersteori om avvikande samt Giorgio Agambens teori om undantag och belägring som fungerarsom en komplettering till förståelsen av hur det är i ett utsatt bostadsområde. Slutsatsernavisar att det är en handfull ungdomar som står för oron som sker i Bäckby och dess handlingarmöjliggörs på grund av misslyckade strukturella åtgärder. De förhållanden vi har funnitavgörande för trygghets upplevelse i Bäckby är inte endast att ungdomar behöversysselsättning, utan det behövs även en spridning av människor med utländsk bakgrund blandetniska svenskar och förebyggande åtgärder från externa aktörer.

Les composés à base du système (Bi, Sb, Te) sont des semi-conducteurs lamellaires à faible gap présentant des écarts à la stchiométrie. Leurs propriétés thermoélectriques sont d'un intérêt technologique considérable. La performance d'un thermo élément est estimée à partir du facteur de mérite Z dépendant des conductivités thermiques et électriques ainsi que du coefficient Seebeck. Des monocristaux sont élaborés par la méthode T. H. M. Cette méthode permet d'obtenir des monocristaux de bonne qualité à des températures inferieures à la température de fusion. Le diagramme de phases nécessaire pour maitriser l'élaboration des cristaux dans des conditions thermodynamiques bien définies a été étudié par des techniques de microcalorimétrie et des recuits d'équilibration pour des températures supérieures à 510c. Les résultats obtenus sont exprimés en termes d'écarts à la stchiométrie donc de concentration de porteurs de type p. Les propriétés électroniques des composés sont étudiées à partir des mesures à 300 k mais aussi entre 100 et 300 k. Pour une concentration de porteurs fixée, le meilleur matériau correspond à une grande valeur de mobilité et une valeur minimale de la conductivité thermique de réseau. Une modélisation des propriétés de transport conduit à l'estimation de la conductivité thermique de réseau, de la masse effective de densité d'états. Cette modélisation permet de fixer la composition optimale et confirmer la forte valeur de Z

ABSTRACT This thesis examines the relationship between adolescent female characters, as represented in the work of three different authors from Norwegian Literature (Henrik Ibsen, Cora Sandel and Tarjei Vesaas), and the particular descriptions of the places inhabited or lands travelled by those characters. From the latter part of the 19th century and throughout the 20th century, childhood and the transition to adulthood have fascinated intellectuals, artists and people of science alike in terms of the wider perspectives offered relating to the process of formation of human identity. None more so than, adolescence – the transitional period between the reality of childhood and that of adulthood. It is a metamorphic, ever-changing period which cannot easily be defined nor labelled; it is characterised by a tumultuous display of contrasting tensions which reflect a vacillating and fermenting identity equilibrium. In short, it is a time of crisis that mirrors the radical revolution within the inner structure of the individual. It causes a heightened creative potential, precisely at a moment when new balances are being forged and refined. In this thesis it is argued that even in texts written by various authors from different periods, it is possible to discover a common tendency to portray “the places of adolescence” with a similar array of symbols and motives. The landscape hosting the adolescent characters tends to display attributes which correspond to those of the characters themselves. Such places could be called isomorphic, using a notion derived from the field of Anthropological Studies. Ambiguity, paradox and a subversive drift are typical of those spaces. They are unstructured, unstable and ephemeral places that perpetually reformulate their own meaning and identity. Within them, everything is possible – every road can be discovered and taken which can lead towards the very edges of imagination. Those places embody realms of pure possibility, intimately connected to the structure of crisis which is characteristic of the adolescence years. Referring to the works of the psychoanalysts Erikson, Winnicott and Kristeva, an open and metamorphic structure has been postulated – a structure of crisis – for all the literary places where the adolescent subject is free to develop and grow in a creative way. Following Roland Barthes’ theory about the Neutral as that which “outplays the paradigm”, the convention adopted is that such places are considered neutral - ambiguous and rebellious, something that cannot be reduced to a fixed definition. Using a category firstly introduced by Erikson regarding identity structures, other places – which at first can bear some resemblances with those of crisis – are considered rigid and close. In them no real movement is possible and all roads reveal themselves as dead ends. Analysing Vildanden (1884, The Wild Duck) by Henrik Ibsen, Elvegaten (1924, The Street On the River) and Barnet som elsket veier (1947, The Child Who Loved the Streets) by Cora Sandel and eventually Is-slottet (1963, The Ice Castle) by Tarjei Vesaas, examples of both types of landscapes are revealed, ones of creativity and growth and others of stasis and death. Referring to Ibsen’s Vildanden, the analysis will focus on the hidden loft where the wild duck is kept in captivity. Although being a real space, the loft is never completely visible to the audience, a detail which triggers the spectator’s and the reader’s imagination. It is a place where fantasy can thrive and where new stories are free to take shape. The creative characteristics within the loft draw an association of imagery with water which holds ambiguous meanings. This place gradually reveals itself as being intimately bound to the young main character’s tragic destiny. In Sandel’s Elvegaten and Barnet som elsket veier isolated streets and country roads are seen to embody freedom and creativity. They contrast sharply with the busy streets of the bourgeois town, where the individual feels hemmed by social conventions and forced into a pattern which is imposed from the outside. No real inner maturation is possible there. In Tarjei Vesaas’ Is-slottet two areas are particularly meaningful for the analysis in question : The ice-castle, where one of the two main characters – Unn – gets lost and dies, and the streets which accompany the other character – Siss – first into a state of confusion and isolation and then back to life. Having tailored relevant methodologies and an original theoretical framework to investigate the nature of similar literary landscapes, future extension using such convention could be applied to analyse works which describe other literary spaces that reflect different crisis points during human development.

Ce travail présente une étude neuromécanique des mécanismes d'action de la lidocaïne lorsqu'elle est utilisée dans la réalisation de blocs anesthésiques dans le cadre de l'évaluation diagnostique de patients présentant un pied équin spastique invalidant. L'originalité de ce travail est de fournir un bilan quantitatif pré thérapeutique de ces patients, utilisant des outils de laboratoire pour mesurer l'excitabilité réflexe et la raideur des fléchisseurs plantaires de la cheville. Les tests cliniques et neuromécaniques ont été pratiqués chez des sujets spastiques avant et après bloc du nerf du soléaire à la lidocaïne, et les résultats obtenus (réduction de l'hyperexcitabilité réflexe et de l'excès de raideur propres aux spastiques) ont servi à valider l'indication d'une neurotomie tibiale sélective, après laquelle les patients ont été réévalués à court et long termes. Pour mieux comprendre les effets de la lidocaïne sur le système neuromusculaire, un modèle rat du suivi des effets de cette molécule sur l'excitabilité réflexe a été mis au point. Ce modèle a permis de préciser le décours temporel d'action de la lidocaïne sur le réflexe de Hoffmann du rat. Par ailleurs, pour étayer l'hypothèse selon laquelle la lidocaïne agit plus sur le versant sensoriel que sur le versant moteur, les effets de la lidocaïne sur la sensibilité des fuseaux neuro musculaires ont été approchés chez le rat par une étude électroneurographique et mécanique
This work presents a neuromechanical study of the action of lidocaine used in the production of an anesthetic block as part of the diagnostic evaluation of patients with spastic equinus foot disability. The originality of this work is to provide a quantitative assessment of these patients before treatment, using laboratory tools to measure the reflex excitability and the stiffness of the ankle plantar flexors. Clinical and neuromechanical tests were performed in spastic patients before and after soleus nerve block with lidocaine, and results (reduction of reflex hyperexcitability and excessive stiffness due to spasticity) were used to validate indication of a selective tibial neurotomy, after which patients were tested again at short and long terms. To better understand the effects of lidocaine on the neuromuscular system, a rat model of monitoring the effects of this molecule on the reflex excitability has been developed. This model has helped clarify the time course of lidocaine action on the H reflex in the rat. Moreover, to support the hypothesis that lidocaine acts more on the sensory component than on the motor component of the reflex pathway, the effects of lidocaine on the muscle spindle function were approached in the rat by an electroneurographical and mechanical analysis of spindle sensitivity

Thesis (PhD)--University of Stellenbosch, 2001.
ENGLISH ABSTRACT: This study aims at highlighting a crucial aspect of Xhosa drama: The portrayal of the role women have been forced culturally to assume in society. A selection of Xhosa plays from three periods (1958 - 1965; 1974 - 1982; and 1988 - 1997) is examined. In the process of the study, the analysis and the interpretation of these dramas as well as the depiction of women characters is examined. Authors of the ten dramas under study advocate change through the powerful forces of gender stereotypes and culture distortions. The attributes that the authors commonly ascribe to women characters are passivity, irrationality, compliancy and incorrigibility. An examination of the reasons behind this proliferation of these female stereotypes and the lack of realistic women characters is undertaken. The study posits reasons why particular stereotypes appear in the works of several authors over a period of time. The women characters are products of social conditioning, that is, ideals or counter-ideals of the prevailing values of the authors' culture. They are a symbolic fulfillment of the writers' needs. The broad cultural perspectives of the authors also shape the texts they produce. These dramas treat issues and themes, which become central to the formal and structural ordering of the drama. Such themes have an impact at times on form and structure. In each case the ideology of the class represented by authors under study is indeed reflected in the text, to its detriment. The dominating themes in the ten dramas are forced marriages and women abuse. The authors are so preoccupied with injustices against women that they distort certain cultural aspects by, for example, exaggeration. Women are constantly depicted as victims, while there are no indications in the authors' depictions of women that perceptions of their cultural role and status are in reality undergoing changes. The thesis is arranged as follows: Chapter 1 introduces the aim, the scope, the theories and the methods of the study. Chapter 2 deals with the development of plot within episodes in the dramas of the first literary period (1958 - 1965). These episodes depict the different phases of the dramas. A critical evaluation of the dramas by motivating their positive and negative aspects is undertaken. Chapter 3 deals with the development of plot within episodes in the dramas of the second literary period (1974 - 1982). As in the first literary period, a critical evaluation of the dramas by motivating their positive and negative aspects is examined. Chapter 4 deals with the development of plot within episodes in the dramas of the third literary period (1988 - 1997). A critical evaluation of the dramas by motivating their good and bad points is undertaken. Chapter 5 deals with woman as character in Xhosa dramas under study. A detailed analysis of the main woman character in each drama is undertaken. Furthermore, a critical summary of how the woman has been portrayed in the dramas is presented. Chapter 6 presents depiction of Xhosa culture in the Xhosa dramas. From each drama, certain selected aspects of culture are explored and an investigation of the portrayal of these aspects is undertaken. Chapter 7 summarizes the findings of the study.
AFRIKAANSE OPSOMMING: Die doelstelling van hierdie studie is om 'n kern aspek van Xhosa drama te belig: die rolle wat vroue kultureel gedwing is om te vervul in die gemeenskap. 'n Seleksie Xhosa dramas vanuit drie tydperke (1958 - 1965; 1974 - 1982; en 1988 - 1997) word ondersoek. In die loop van die studie, ontleding en interpretasie van hierdie dramas word die uitbeelding van vroue karakters ook ondersoek. Die skrywers van die tien dramas wat bestudeer word, betoog vir verandering deur middel van die sterk kragte van stereopites en kultureelverwronge voorstellings. Die eienskappe wat die skrywers algemeen toeskryf aan vroue karakters is passiwiteit, irrasionele optrede, gehoorsaamheid en deugsaamheid. 'n Ondersoek na die redes vir die proliferasie van hierdie vroulike stereotipes en die tekortkoming aan realistiese vroue karakters in Xhosa dramas word uitgevoer in die studie. Die studie voer redes aan waarom bepaalde stereotipes in die werk van verskeie skrywers oor 'n tydperk verskyn: hulle vrouekarakters is die produk van sosiale kondisionering, dit wil sêm ideale of teen-ideale van die heersende waardes van die skrywer se kulturele agtergrond en 'n simboliese vervulling van die skrywer se behoeftes. Die algemene kulturele perspektiewe van die skrywers beïnvloed en vorm ook die tekste wat hulle lewer. Hierdie dramas behandel naamlik vraagstukke tematies wat sentraalook bepalend is ten opsigte van die vorm en struktuur van die drama. Sodanige temas het gevolglik in bepaalde gevalle 'n invloed op die vorm en struktuur van die drama. Voorts word die ideologie van die klas verteenwoordig deur die skrywers in elke geval gereflekteer en die teks tot bepaalde nadele daarvan. Die prominente temas in die tien dramas is gedwonge huwelike en vrouemishandeling. Die skrywers is so gepre-okkupeer met die ongeregtighede teenoor vroue dat hulle bepaalde kulturele aspekte verwring deur, byvoorbeeld, buitensporige voorstellings. Vroue word voortdurend voorgestel as slagoffers, terwyl daar feitlik geen aanduidings is in die skrywer se voorstelling van vroue, dat persepsies oor hulle kulturele rol en status inderwaarheid besig is om veranderinge te ondergaan. Die proefskrif is soos volg gestruktureer: Hoofstuk 1 gee die doelstellings, omvang, teorieë en metodes wat in die studie gevolg word. Hoofstuk 2 behandel die ontwikkeling van intrige binne verskillende episodes in die dramas van die eerste literêre periode (1958 - 1965). Hierdie episodes gee 'n uitbeelding van die verskillende fases van die dramas wat in die studie ondersoek word. 'n Kritiese evaluering word van die dramas gedoen deur die positiewe en negatiewe aspekte daarvan te motiveer. Hoofstuk 3 behandel die ontwikkeling van intrige binne die episodes van die dramas van die tweede literêre periode (1974 - 1982). Soos vir die eerste literêre periode, word 'n kritiese evaluering gedoen van die dramas deur onder andere die positiewe en negatiewe literêre aspekte daarvan te motiveer. Hoofstuk 4 ondersoek die ontwikkeling van die intrige binne die episodes in die dramas van die derde literêre periode (1988 - 1997). Die kritiese evaluering van hierdie dramas sluit, soos vir die vorige periodes, 'n gemotiveerde beskouing in van die positiewe en negatiewe aspekte. Hoofstuk 5 ondersoek die vrou as karakter in die Xhosa dramas wat bestudeer word. 'n Gedetaileerde analise van die hoof-vroue karakters in elke drama word gedoen. Daarna word 'n kritiese oorsig aangebied van hoe die vrou voorgestel word in die dramas wat bestudeer is. Hoofstuk 6 bied 'n uitbeelding van Xhosa kultuur in die dramas wat ondersoek is. Bepaalde aspekte van kultuur word vir elke drama ondersoek en die uitbeelding van hierdie kultuur aspekte word behandel. Hoofstuk 7 bied 'n opsomming van die belangrikste bevindinge van die studie.

GONÇALVES, Fabricio Mota. Evapotranspiração e coeficientes de cultivo (KC) da cana-de-açúcar irrigada por gotejamento subsuperficial. 2010. 64 f. Dissertação (Mestrado em engenharia agrícola)- Universidade Federal do Ceará, Fortaleza-CE, 2010.
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Sugar cane is one of the crops with the highest level of water consumption, with a high evapotranspiration demand throughout most of its cycle. Knowledge of the sugar cane water demand, the time that irrigation should be applied, and how to irrigate the crop are becoming increasingly important for the sustainable development of irrigated sugar cane cultivation, especially in areas of low water availability, as it is the case in northea stern Brazil. The experiment was carried out at the Curu Experimental Field (property of the Embrapa Tropical Agroindustry), located in the Curu-Paraipaba Irrig ation Project, city of Paraipaba-CE (3 ° 29 '20''S, 39 ° 9' 45''W and elevation 30m), in order to determine the evapotrans piration and crop coefficients (Kc) of sugarcane (Saccharum L. officinarium), subsurface drip-irrigated. It was used the SP 6949 sugar cane variety, planted in a spacing of 1.8 m between double rows and 0.4 m between rows within the double row. As to t he irrigation, we used one lateral water line for each double row, buried at a depth of 0.15 m, w ith self-compensating drip emitters, with a flow rate of 1 L h-1, spaced 0.5 m on the water line. The crop was irrigated daily and there were three fertigations per week. The irrigation de pth was periodically adjusted, keeping the soil water potential between -8 kPa to -20 kPa. The crop evapotranspiration (ETc) was determined using a wei ghing lysimeter with a surface area of 2.25 m 2. The reference evapotranspiration (ETo) was estimated by the FAO Penman-Monteith method. The durations of the phenological stages of cane sugar were estimated through analysis of soil cover, with the use of digital images. Durations of 31, 49, 237 and 118 days were observed, respectively for initial, crop development, mid-season and late season stages. The yields achieved within and outside the lysimeter were respectively 144.4 and 108.8 t ha -1 . The total ETc observed during the cycle of the sugar cane was 1074.1 m m, with maximum values of 6.6 mm d-1 during the mid-season stage. Observed Kc values for initial, mid-season and late season stages were respectively 0.23, 1 .03 and 0.50. In the crop development stage, the relationship between Kc and the (crop) soil cover was represented with good accuracy by a negative quadratic model.
A cana-de-açúcar é uma das culturas com maior consumo de água, apresentando uma alta demanda evapotranspirativa ao longo da maior parte do seu ciclo. O conhecimento das necessidades hídricas da cana-de-açúcar, do momento de aplicação da água requerida pela mesma e a forma de aplicação torna-se cada vez mais importante para o desenvolvimento sustentável da sua produção irrigada, principalmente em regiões de pouca disponibilidade hídrica, como é o caso da região Nordeste do Brasil. O experimento foi conduzido no Campo Experimental do Curu, pertencente à Embrapa Agroindústria Tropical localizado no Perímetro Irrigado Curu-Paraipaba, município de Paraipaba-CE (3° 29’ 20’’ S, 39° 9’ 45’’ W e altitude de 30 m), com o objetivo de determinar a evapotranspiração e os coeficientes de cultivo (Kc) da cana-de-açúcar (Saccharum officinarium L.), irrigada por gotejamento subsuperficial. Utilizou-se a variedade de cana SP 6949, plantada no espaçamento de 1,8 m entre fileiras duplas e 0,4 m entre linhas dentro da fileira dupla. Na irrigação utilizou-se uma linha lateral para cada fileira dupla, enterrada na profundidade de 0,15 m, com gotejadores autocompensantes, com vazão de 1 L h-1, espaçados de 0,5 m na linha. A cultura foi irrigada com freqüência diária e foram realizadas três fertirrigações por semana. A lâmina de irrigação foi ajustada periodicamente, mantendo-se o potencial de água no solo entre -8 kPa e -20 kPa. A evapotranspiração da cultura (ETc) foi determinada utilizando-se um lisímetro de pesagem com área superficial de 2,25 m2. A evapotranspiração de referência (ETo) foi estimada pelo método FAO Penman-Monteith. As durações das fases fenológicas da cana-de-açúcar foram estimadas por meio da análise da cobertura do solo pela cultura, determinada com o uso de imagens digitais. Foram observadas durações de 31, 49, 237 e 118 dias, para as fases inicial, de desenvolvimento, intermediária e final, respectivamente. A produtividade alcançada dentro e fora do lisímetro foi de 144,4 e 108,8 t ha-1, respectivamente. A ETc total observada durante o ciclo da cana-de-açúcar foi de 1.074,1 mm, com valores máximos da ordem de 6,6 mm d-1 durante a fase intermediária. Foram observados valores de Kc iguais a 0,23, 1,03 e 0,50, para as fases inicial, intermediária e final, respectivamente. Na fase de desenvolvimento vegetativo a relação entre o Kc e a cobertura do solo pela cultura foi representada com bastante exatidão por um modelo quadrático negativo.