This thesis presents an empirical analysis of the unemployment hysteresis in the Czech Republic on quarterly data from 1999 to 2015. The hysteresis is modelled by allowing for: (i) impact of the cyclical unemployment on the NAIRU; (ii) impact of the long-term un- employment on the NAIRU. Models are written in state space form and estimated using Bayesian approach. The main contributions of this thesis are as follows. The results pro- vide robust evidence in favour of the hysteresis in the Czech Republic, but precise size of the hysteresis effect is surrounded by relatively large uncertainty. Posterior mean estimates of key parameters indicate that in response to increase in the cyclical unemployment of 1 percentage point, the NAIRU increases by 0.15 percentage points. The first specification of the hysteresis implies that the hysteresis induced changes in the Czech Republic's NAIRU of at most 1 percentage point. The hysteresis specified as impact of the long-term unemploy- ment on the NAIRU then implies even weaker effect, inducing changes in the NAIRU of at most 0.6 percentage points. The models are estimated jointly with the hybrid Phillips curve identified using survey forecasts as proxies for the expectations. Estimate of the expecta- tions' parameter 0.65 indicates the forward-looking nature of the Czech...

This research work focuses on the geometry and shape effects on submicron magnetic material. A web based micromagnetics program is written to model the hysteresis loop of nano magnetic samples with arbitrary geometry shapes and multiple magnetic materials. Three material samples have been modeled with this program along with nano magnets with a variety of geometric shapes. Shape anisotropy has been introduced to a permalloy ring by adding a cross-tie structure with various widths. The in-plane hysteresis loop and reversal behavior have no notable difference in direction parallel to the cross-tie, but greatly changed in perpendicular and diagonal directions. The switching field distribution is significantly reduced. The two distinct "onion" bit states of the modified ring elements are stabilized in the hysteresis in the diagonal direction. The changes in the modified rings make them better candidates for Magnetic Random Access Memory elements. Two Pac-Man elements, PM I and PM II, geometrically modified from disc and half disc respectively, are modeled. The PM I element undergoes a magnetic reversal through a two-stage mechanism that involves nucleation in the left and right middle areas followed by vortex core formation and vortex core motion in the lower middle area. The reversal process of the PM II element lacks the vortex core formation and motion stage. The switching field of the PM I and PM II elements are the same but the switching field distribution of the PM II elements is much narrower than that of the PM I element. Only the PM II element meets MRAM application requirements. The thickness dependence of the magnetic properties of a core-shell structure has been studied. The nano particles have a cobalt core and a permalloy shell. The nano spheres are the same size but with various shell thickness. Simulations reveal a multi-stage reversal process without the formation of a Bloch wall for thin-shell structure and smooth reversal process with the formation and motion of a Bloch wall for thick-shell structure. Gradual transition of the hysteresis loop patterns has been observed.

Although a superconductor has zero resistivity when carrying a direct current, losses do occur when it is exposed to an alternating magnetic field and/or is carrying an alternating current. The magnitude of these so-called AC losses depends on the operating temperature, the amplitude and the direction of the magnetic field, the transport current, and the frequency. Therefore, the use of high-temperature superconductors, HTSs, in electric power components such as cables, transformers or reactors, requires knowledge of the AC losses. This thesis deals with the development of AC loss models for HTSs, mainly for Bi-2223 tapes. In particular, the orientation of the applied magnetic field is taken into account in the modelling. The basis for the models is the results of experimental investigations. The basic concepts of HTSs with special emphasis on the modelling of AC losses are presented. These can be broken down into several components. Their sources and natures are described. One of the components is the hysteretic loss and it is the dominating loss in AC applications at power frequencies. Therefore, the other loss components are neglected in the modelling. Models are presented and the associated parameters are investigated with respect to their dependence of the magnetic field as well as the temperature. The AC losses for parallel and perpendicular magnetic field with respect to the wide side of the tape are calculated numerically. Moreover, a semi-empirical model for intermediate angels of the applied magnetic field is proposed. The comparisons show good agreement with experimental results. Keywords: High-temperature superconductors, AC loss modelling, hysteresis, E-J characteristic. / <p>QCR 20161026</p>

A idade afeta vários fatores do sistema locomotor, incluindo as propriedades mecânicas. Os ossos são materiais viscoelásticos e uma característica destes materiais é a ocorrência de histerese quando são submetidos a ciclos de carregamento e descarregamento. Nesta pesquisa nós estudamos a tensão máxima e a energia de histerese de fêmures de ratas de diferentes idades, submetidos a ensaios de flexão em três pontos. Foram utilizados os fêmures de 90 ratas fêmeas, da raça Wistar, os animais foram divididos em três grupos de 30 animais de acordo com a idade: 25 dias (A), 65 dias (B) e 365 dias (C). Cada grupo foi subdividido em 3 lotes de 10 animais. Todos os fêmures foram submetidos a ensaio de flexão em três pontos. De cada par de ossos, o fêmur esquerdo foi submetido a carregamento até a ruptura (ensaio destrutivo) e, o fêmur direito foi submetido a carregamento até 40% (lote I), 60% (lote II) e 80% (lote III) do limite elástico obtido do fêmur contralateral e, então, descarregado. Comparando os grupos B e C, as energias de carregamento e de descarregamento aumentaram com a idade e com o nível de carregamento, mas, a energia de histerese aumentou somente com o nível de carregamento. Na comparação entre os três grupos, a tensão máxima aplicada aumentou significativamente com a idade (p 0,001) e, a perda de energia relativa foiestatisticamente igual entre todos os lotes de uma mesma idade, 25 dias (p=0,136), 65 dias (p=0,583) e 365 dias (p=0,177), mas diminuiu significativamente com a idade (p<0,001). Podemos concluir que a idade exerceu influências na tensão máxima e no comportamento viscoelástico dos fêmures de ratas, mas são necessários estudos mais profundos para compreendermos melhor este material. / Ageing affects many features of the locomotor system, including its mechanical properties. Bone is a viscoelastic material what means that it displays the phenomenon of hysteresis when submitted to loading-unloading cycles. In the present research we studied the behavior of the ultimate stress and the energy of hysteresis of femurs of rats in different ages, when tested in bending. Ninety femurs collected from female Wistar rats were used. There were three groups classified according to the animal age: 25 days (A), 65 days (B) and 365 days (C). The groups were divided into 3 subgroups (10 animals each). All the femurs were submitted to a three-point bending test. For each paired bones, the left femur was loaded until failure and the right femur was load to 40% (subgroup I), 60% (subgroup II) and 80% (subgroup II) of the yield load in relation to the opposite side femur and, then, unloaded. Comparing the groups B and C, the energies of loading and unloading increased with age and loading level, but, the energy of hysteresis increased only with loading level. The comparison among the three groups showed that the ultimate stress increased with age (p 0.001) and, the relative energy loss was equal for the subgroups belonging to the same group, A (p=0.136), B (p=0.583) and C (p=0.177), but different when the different groups were compared (p<0.001). It was concluded that ageing affects both the ultimate stress and the viscoelastic behavior of rat femurs, but further studies are necessary to deepen the knowledge in such matter.

Foi desenvolvido um novo método para a determinação da polarização ferroelétrica de polímeros ferroelétricos, em particular do PVDF estirado biaxialmente. A técnica consiste em manter constante a corrente através da amostra e medir a evolução da tensão (V versus t) entre os eletrodos da mesma. As medidas foram realizadas em ambiente com atmosfera de ar superseco o que permite desprezar a condução elétrica das amostras, simplificando sobremaneira as equações do problema. Considera-se a existência de dois tipos de polarização: a ferroelétrica, com tempo de chavamento desprezível, e uma polarização elétrica foram realizados em duas situações distintas: com chaveamento e sem chaveamento ferroelétrico. O procedimento permite avaliar a dependência da polarização ferroelétrica com o campo, determinada a partir da equação geral da corrente. Para se descrever a resposta da polarização elétrica dependente do tempo, usa-se o princípio da superposição e assume-se que ela está em fase com o campo elétrico aplicado (processo lento). Será mostrado que é possível determinar a polarização ferroelétrica do polímero PVDF estirado biaxialmente sem a necessidade de determinar a formas funcionais da polarização dependente do tempo e de se conhecer o valor da capacitância da amostra. / In this work a novel method was developed for the determination of the ferroelectric polarization of ferroelectric polymers, in particular of biaxially stretched PVDF. The technique consists of maintaining constant the current through the sample and to measure the evolution of the bias voltage (V versus t) on the electrodes. Measurements were performed in super-dry air, which allows one to neglect the electric surface and volumetric conduction of the samples, simplifying the equations of the problem. It is considered the existence of two polarization types: the ferroelectric, with a very short switching time, and a another polarization dependent of the time. The processes for studying the electric polarization were accomplished in two different situations: with switching and without ferroelectric switching. The procedure allows evaluating the dependence of the ferroelectric polarization on the electric field, determined starting from the general equation of the current. To describe the time dependent polarization it is used the principle of superposition and the polarization value assumed to be in phase with the applied electric field (slow process). It will be shown that it is possible to determine the ferroelectric polarization of the material without the need of the functional form of the polarization and the value of the capacitance of the sample.

Orientador: Luci Regina Muzzeti / Banca: Caren Elisabeth Studer / Banca: Aracy Alves Martins / Banca: Ernesto Sérgio Bertoldo / Banca: Cássia Regina Coutinho Sossolote / Resumo: O trabalho discute - à luz do referencial bourdieuniano - a constituição do habitus linguístico de professores de Língua Portuguesa em formação, analisando-se a atuação linguística metacomunicativa de estagiários do curso de Letras, com foco na escrita por eles utilizada para a transmissão dos conteúdos culturalmente legítimos aos alunos do Ensino Fundamental e Médio. O tratamento do tema, sob o viés sociológico, pautou-se em uma metodologia que mescla estudo de caso e análise situacional, utilizando-se da técnica de bricolage, com abordagens quantitativa e qualitativa. A exposição dos resultados apresenta: 1) reflexões sobre o referencial teórico de Bourdieu, desenvolvendo as principais categorias que nortearam a análise e que, de alguma forma, condicionam a escolha do curso e o desempenho dos alunos de Letras-Português, seja na classe ou atuando no estágio; 2) um estudo documental, contextualizando a Universidade Federal de Rondônia - UNIR, o curso de Letras-Português, desde sua fundação até os dias atuais; 3) o perfil patrimonial dos estudantes de Letras-Português da UNIR; 4) análise do capital linguístico dos estagiários de Letras-Português, considerando situações de uso da língua escrita em sala de aula. A análise situacional foi realizada a partir da observação e registro de aulas ministradas em escolas públicas por estagiários do curso de Letras-Português durante o ano de 2008. Foram detectados: a) erros de grafia decorrentes de interferência da fala na escrita; b) inadequação de pontuação e ausência de acentuação gráfica; c) confusão entre formas e tempos verbais do futuro do subjuntivo de verbos com anomalia morfológica; d) desconhecimento de conteúdos gramaticais no âmbito da fonética/fonologia, morfologia sintaxe e semântica. Na discussão de tais fatos considera-se o efeito de histeresis do habitus (Cf. Bourdieu, 1972)... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The paper discusses - in light of the Bourdieu's theoretical reference - the constitution of the linguistical habitus of Portuguese Language teachers in training, analyzing the metacommunicative linguistical performance of trainees of a course of Portuguese, focusing the writing used by them for transmission of culturally legitimate content to students of elementary and high school. The treatment of the subject, under the sociological perspective was based on a methodology that combines the case study and situational analysis, using the technique of bricolage, with quantitative and qualitative approaches. The exposure of the result presents: 1) reflections on the theoretical framework of Bourdieu, which developed the main categories that guided the analysis and, in some way, influence the choice of course and the performance of students of Portuguese, either in class or acting on stage; 2) a documentary study, contextualizing the Federal University of Rondônia - UNIR, the course of Portuguese, from its foundation until today; 3) the patrimony profile of the students of Portuguese; 4) the analyzis of the linguistical capital of the Portuguese trainees, considering situations of use in written language in the classroom. The situational analysis was carried out from the observation and recording of classes taught by trainees in public schools during the year 2008. The research detected: a) spelling errors due to the interference of speech in writing; b) inadequacy of punctuation and lack of graphic accents; c) confusion between forms and tenses of the subjunctive future of verbs with malformations; d) lack of grammatical contents in phonetics/phonology, morphology, syntax and semantics. In discussing these facts we consider the effect of hysteresis of habitus (cf. Bourdieu, 1972) as a causative factor of non-use of distinctive linguistic capital accumulated by the Portuguese language teachers in training. / Doutor

O fenômeno de hysteresis, originalmente estudado pela física, foi utilizado em economia na área de comércio internacional a fim de formular um modelo teórico que explicasse as diferentes reações do mercado a variações da taxa de câmbio. O objetivo desse trabalho é dar continuidade a literatura sobre o assunto e testar a hipótese de histerese para o mercado de importações brasileiro.Fez-se o uso da metodologia de painel com valores limiares a fim de testar se essa hipótese é válida para esse mercado analisando a equação de demanda brasileira por importações. Chegamos a conclusão que existem indícios de histerese nesse mercado quando analisamos os dados desagregados para os diferentes países que fazem parte da pauta de importação brasileira. / The hysteresis, originally studied by physics, has been used in economics in the area of international trade in order to formulate a theoretical model to explain the different market reactions to changes in the exchange rate. The aim of this work is to continue the literature on the subject and teste the hypothesis of hysteresis in the import market. It was used the panel with threshold values effect model in order to teste whether this hypothesis is valid. It is concluded that there is evidence of hysteresis in this market when analysing disaggregated data for different countries that are part of the Brazilian import agenda.

Desde que Markwald e Puga (2002) encontram relações assimétricas entre taxa de câmbio e quantidade de empresas exportadoras, diversos autores investigaram a presença de histerese nas exportações de produtos manufaturados brasileiros. Todavia, os testes utilizados limitaram-se à inferência sobre a hipótese de histerese, provendo pouca informação para análise de política. Este trabalho propõe uma metodologia para averiguar a teoria, baseada no modelo econométrico de painel com efeitos de valores limiares de Hansen (1999b); e segue uma linha de testes com predições teóricas, nos quais choques anormais na taxa de câmbio podem provocar mudanças de elasticidade-preço. O procedimento permite a interpretação direta dos coeficientes para análise de política, captando características de não-linearidade e assimetria. Aplicou-se o método em um modelo de demanda por exportações brasileiras, no período 1999-2010. A hipótese de histerese foi confirmada, sendo os principais resultados: (i) a elasticidade-renda é maior que a elasticidade-preço quando choques recentes no relativo de preços são menores que 5:2% ou maiores que 5:7%; e (ii) quedas absolutas ou relativas nos preços de exportação afetam mais as quantidades exportadas do que aumentos de magnitude semelhante. Tais fatores indicam uma alta competitividade no comércio internacional; e políticas que promovam reduções de custos e aumentos da produtividade são importantes na promoção das exportações. / Since Markwald e Puga (2002) found asymetric relationships between exchange rates and the number of exporting companies, several authors verified the presence of hysteresis on Brazilian exports of manufactured goods. However, the tests used were limited to the inference about the hypothesis, providing little information for policy analysis. This work proposes a methodology to verify the theory, based on Hansen (1999b) panel threshold model and follows the kind of tests concerned about theoric predictions of the model, in which abnormal shocks in the exchange rate can cause changes in price-elasticity. The procedure allows the direct interpretation of the coefficients for policy analysis, capturing the characteristics of nonlinearity and asymetry. The method was applied on a model of demand for Brazilian exports in the 1999-2010 period. The hysteresis hypothesis was confirmed and the main results were: (i) the income-elasticity is greater than the price-elasticity when recent shocks in relative prices are less than 5:2% and greater than 5:7%; and (ii) absolut or relative falls in exports prices affects amounts exported more than increases of similar extent. These factors indicate a high competitiveness in international trade; and policies that promote cost reductions and productivity increases are important in promoting exports.

Desenvolveu-se um sistema para medir a constante dielétrica complexa de amostras dielétricas, de construção simples, versátil e de baixo custo. A medida é feita aplicando-se uma tensão senoidal e fazendo-se a aquisição do sinal aplicado e do sinal da resposta elétrica (carga elétrica). Emprega-se uma placa A/D para a aquisição de dados com taxa de amostragem de 100 Ksamples/seg e através da transformada de Fourier discreta destes sinais determina-se a impedância complexa da amostra, a partir da qual calcula-se a constante dielétrica complexa. A placa utilizada e o circuito de medida da carga elétrica introduzem defasagens indesejáveis nos sinais, cujas correções são feitas através de programa no computador usado para aquisição dos sinais. O sistema mostra um desempenho similar àqueles dos equipamentos comerciais para freqüências no intervalo de 0,1H.z a 1KHz, sendo testado com componentes resistivos e capacitivos e posteriormente em amostras de Teflon FEP, poli(fluoreto de vinilideno) e seus copolímeros com trifluoretileno. O sistema também foi utilizado para medir o deslocamento elétrico nos polímeros ferroelétricos sob a aplicação de campos elevados. Neste caso determinaram-se as curvas de histerese dielétrica e os deslocamentos de primeira, segunda e terceira ordem. / A low cost and a simple experimental system for measuring the complex dielectric constant of dielectric samples were developed. Measurements were performed measuring the electric charge response resulting from the application of a sinusoidal voltage. The system was based on an A/D acquisition board with sampling rate of 100 Ksamples/sec. The complex impedance was calculated using the discrete Fourier transform from which the complex dielectric constant was found. The phase differences introduced by the A/D board and the amplifiers circuits were connected by software. The setup showed that the results are comparable to that ones obtained with commercial impedance analyzers in the range of frequencies between 0.1 Hz and 1 KHz. Such measurements were obtained using resistors and/or capacitors and also using samples of Teflon FEP, PVDF and its copolymers with trifluorethylene. The setup was also capable to measure the electric displacement in ferroelectric polymers submitted to high fields. Hysteresis loops and the nonlinear electric displacement of first, second and third order were measured.

The thesis draws upon six published and peer reviewed papers and a peer reviewed book chapter. An overview of each paper is followed by the publication and then an explanation of how each has contributed to the emerging research profile and methodology. There follows a critical overview and rationale of the developing and emerging research profile and the move from a constructivist grounded methodology to a Bourdieuian theoretical and methodological position. This thesis focuses on the process of social reproduction and change in the contemporary mountaineering and climbing field. A central theme in this thesis is the relationship between social structure and individual agency. The adoption of the Bourdieuian approach represents a conceptual break with previous understandings of action, agency, objectivism, subjectivism, the individual and society. Habitus becomes a main mechanism to explore and analyse the process of social change and reproduction in the contemporary climbing and mountaineering field. Habitus makes it possible to understand and account for the dynamic and spontaneous actions of individuals as well as the process of social reproduction and change. At the centre of the process of social change is the relationship between the habitus and the field. It is through a detailed analysis of the relationship between the habitus and the field that is possible to understand the process of structural change and the conditions where individuals are most likely and able to challenge doxa. In the modern climbing context, women, particularly from the middle classes, are becoming empowered through the transformation of their bodies and the construction of often complex and contradictory identities. These women are placed to take advantage of new emerging social relations and opportunities occurring as a result of hysteresis. However, this has implications for the identities and position of established climbers, particularly men whose habitus was formed under a previous set of objective conditions, but also other women from subordinate social positions.