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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.
1

The Greenland White-fronted goose Anser albifrons flavirostris : the annual cycle of a migratory herbivore on the European continental fringe /

Fox, Anthony David. January 2003 (has links)
Thesis (DSc.)--National Environmental Research Institute, Denmark. / Includes bibliographical referen.
2

„As long as we can cry about the misery we can joke about it too“ : An intersectional and queer theoretical analysis of a Swedish female-fronted humor series

Lundby, Frida January 2015 (has links)
The aim of this thesis is to use intersectional queer theoretical analysis in order to investigate if the Swedish female-fronted humor series "Mia och Klara" can be understood as feminist. Through semiotic analysis of discourses in the material, the appearance and non-appearance of different social location and the portrayal of these can be established. The social location-analysis coupled with the Bechdel test will show us that the show can be perceived as female-focused but that certain characters are paradoxical and challenge the primacy of the male gaze through storyline and camera angles. The TV-series can to the most part be seen as a liberal- and post-feminist storyline that reinforces and re-affirms a white, Swedish, femininity project.
3

Avaliação do manejo e do potencial zoonótico de papagaios-verdadeiros (Amazona aestiva) mantidos em cativeiro domiciliar /

Bonello, Fábio Luís. January 2006 (has links)
Orientador: Cáris Maroni Nunes / Banca: Marcelo Vasconcelos Meireles / Banca: Eliana Reiko Matushima / Resumo: A manutenção de animais silvestres em cativeiro domiciliar como animais de estimação é bastante comum no Brasil e os papagaios tem sido preferidos por serem considerados curiosos, inteligentes e divertidos, além de serem excelentes imitadores e faladores. Entretanto, os papagaios-verdadeiros (Amazona aestiva) podem ser fontes de infecção de algumas zoonoses. Neste trabalho foram estudados 50 papagaios-verdadeiros mantidos em cativeiro domiciliar no município de Araçatuba, São Paulo. As condições sócio-econômicas e os manejos sanitário e nutricional das aves, bem como o contato com os residentes foram avaliados por meio de visitas às casas. Os resultados revelaram manejos sanitário e nutricional inadequados na maioria dos casos, estreito contato com os papagaios e falta de conhecimento sobre enfermidades dos mesmos. Não foi isolada Salmonella sp. nas amostras de fezes, enquanto Escherichia coli estava presente em três animais e estruturas leveduriformes foram encontradas na maioria deles. Cryptosporidium sp. foi encontrado em uma das amostras. Pode-se concluir que o estreito contato dos residentes com as aves e as condições sanitárias inadequadas podem favorecer a ocorrência de zoonoses nas residências avaliadas. A presença de Cryptosporidium sp., caso se trate de uma espécie zoonótica, indica a possibilidade da transmissão de criptosporidiose de papagaios para o homem em condições de cativeiro domiciliar. / Abstract: The maintenance of wild animals in domiciliary captivity as pets has been common in Brazil and parrots are preferred because they are considered curious, intelligents, amusing, excellent talkative and mimics. However, the blue- fronted amazon parrot (Amazona aestiva) can be source of some zoonosis infections. In the present study the sanitary and nutritional management of 50 blue-fronted amazon parrots kept in domiciliary captivity in Araçatuba city, SP, as well as the occurrence of zoonosis agents in stools samples, social-economic conditions and residents-birds contact were evaluated. Results showed inadequate sanitary and nutritional management in the majority of the cases, strait contact with the parrots and lack of knowledge about parrots diseases. Salmonella was not found in stool samples while Escherichia coli was present in three samples and levedures-like structures were found in the majority them. Cryptosporidium was found in one sample. We can conclude that the close contact with the birds and the uncorrect management can favour occurrence of zoonosis in evaluated residences. The presence of Cryptosporidium sp. Indicates transmition possibility of cryptosporidiosis, in case of zoonotic specie, from parrots to humans in domiciliary captivity conditions. / Mestre
4

The Effect of Teacher-Fronted and Group Work Techniques on Beginning Chinese as a Foreign Language Learners' Acquisition of Grammar in a Performed Culture Classroom

Lin, Chieh-Ting 14 August 2008 (has links) (PDF)
This study focuses on the effect of teacher-fronted and group work instruction on beginning Chinese as a Foreign Language learners' understanding and ability to use grammar principles correctly in a Performed Culture class setting. Three sections of beginning Chinese classes at Brigham Young University were selected to participate in the study. Each section instructor was assigned one of the following teaching techniques: teacher-fronted, group work, or a combination of both teacher-fronted and group work. Quizzes focusing on grammar were given before and after instruction to all students as pre-tests and post-tests. The results showed that students being taught with the teacher-fronted classroom instruction style outperformed the group work section on quizzes, while there was no significant statistical difference between sections on oral performances. Surveys given to students showed that students' attitudes towards teaching styles did not correlate with their quiz scores.
5

Nouvelle conception des bobinages statoriques des machines à courant alternatif pour réduire les effets négatifs des dV/dt / New design of stator windings of AC machines for reducing the negative effects of dV/dt

Mihaila, Vasile 14 December 2011 (has links)
L’émergence du concept d’un avion plus électrique implique une refonte en profondeur des réseaux embarqués. L’axe principalement développé repose sur une augmentation de la tension du réseau et un passage au bus continu. Le contrôle des actionneurs électriques embarqués passe alors par l’utilisation massive de convertisseurs électroniques qui vont imposer des fronts de tension très raides et des contraintes particulières aux enroulements des machines. Les oscillations pseudopériodiques qui suivent ces fronts raides sont à l’origine de champs électriques intenses qui peuvent dépasser le seuil d’apparition des décharges partielles (PDIV) et de ce fait provoquer une dégradation rapide des isolants classiques qui sont à base de polymères. Le travail effectué dans cette thèse est centré sur l’étude d’une nouvelle méthode de conception des bobinages permettant la réduction des problèmes de décharges partielles. Un dispositif expérimental mis au point dans ce cadre reproduit les contraintes imposées par des convertisseurs modernes et permet de mesurer les tensions inter-spires d’une bobine. L’étude expérimentale met en évidence les phénomènes àprendre en compte avec ce type d’alimentation et donne une première idée des axes d’optimisation envisageables. Un modèle prédictif capable de donner la distribution des tensions inter-spires, en réponse à un front raide de tension, aide à identifier les points critiques. Les paramètres constitutifs de ce modèle ont été déterminés en utilisant des méthodes analytiques, expérimentales et numériques. Compte tenu de la complexité du modèle, un outil numérique automatisé a été élaboré afin de simuler le modèle des bobines étudiées. Plusieurs types de bobinage ont été analysés et optimisés avec succès. Cette optimisation consiste à diminuer la tension inter-spires en agissant sur l’arrangement des fils dans les encoches. L’utilisation des bobines optimisées avec cette méthode permet d’envisager une nette amélioration de la fiabilité des machines électriques. / The emergence of the concept of a more electric aircraft requires a major overhaul of onboard grid. The main developed axis is based on an increase in the grid voltage and a switch to DC bus. In this context, the onboard electric actuators are supplied through power electronic converters that will impose very fast voltage fronts and particular constraints in the windings of the machines. The transient over-voltages that follow the steep-fronted pulses are the source of intense electric fields which may exceed the partial discharge inception voltage (PDIV) and cause a rapid deterioration of polymer based insulators. This thesis focuses on the study of a new design method of the windings in order to reduce problems of partial discharges. An experimental device developed in this framework reproduces the constraints of modern converters and allows measuring the turn-to-turn voltages of a coil. The experimental study shows the phenomena to be considered with this type of power supply and gives an idea of possible areas for optimization. A predictive model able to give the distribution of turn-to-turn voltages, in response to a steep-fronted voltage, helps to identify critical points. The constitutive parameters of this model were determined using analytical, experimental and numerical methods. Given the complexity of the model, an automated numerical tool has been developed in order to simulate the model of studied coils. Several types of coil have been analyzed and optimized successfully. This optimization consists in reducing the turn-to-turn voltages by acting on the arrangement of the wires in the slots. The use of optimized coils with this method allows envisaging a significantimprovement in the reliability of electrical machines.
6

Avaliação do manejo e do potencial zoonótico de papagaios-verdadeiros (Amazona aestiva) mantidos em cativeiro domiciliar

Bonello, Fábio Luís [UNESP] 27 October 2006 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:27:18Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-10-27Bitstream added on 2014-06-13T20:16:24Z : No. of bitstreams: 1 bonello_fl_me_araca.pdf: 611158 bytes, checksum: 64289841b4b9ab09da7b919f8edbd113 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A manutenção de animais silvestres em cativeiro domiciliar como animais de estimação é bastante comum no Brasil e os papagaios tem sido preferidos por serem considerados curiosos, inteligentes e divertidos, além de serem excelentes imitadores e faladores. Entretanto, os papagaios-verdadeiros (Amazona aestiva) podem ser fontes de infecção de algumas zoonoses. Neste trabalho foram estudados 50 papagaios-verdadeiros mantidos em cativeiro domiciliar no município de Araçatuba, São Paulo. As condições sócio-econômicas e os manejos sanitário e nutricional das aves, bem como o contato com os residentes foram avaliados por meio de visitas às casas. Os resultados revelaram manejos sanitário e nutricional inadequados na maioria dos casos, estreito contato com os papagaios e falta de conhecimento sobre enfermidades dos mesmos. Não foi isolada Salmonella sp. nas amostras de fezes, enquanto Escherichia coli estava presente em três animais e estruturas leveduriformes foram encontradas na maioria deles. Cryptosporidium sp. foi encontrado em uma das amostras. Pode-se concluir que o estreito contato dos residentes com as aves e as condições sanitárias inadequadas podem favorecer a ocorrência de zoonoses nas residências avaliadas. A presença de Cryptosporidium sp., caso se trate de uma espécie zoonótica, indica a possibilidade da transmissão de criptosporidiose de papagaios para o homem em condições de cativeiro domiciliar. / The maintenance of wild animals in domiciliary captivity as pets has been common in Brazil and parrots are preferred because they are considered curious, intelligents, amusing, excellent talkative and mimics. However, the blue- fronted amazon parrot (Amazona aestiva) can be source of some zoonosis infections. In the present study the sanitary and nutritional management of 50 blue-fronted amazon parrots kept in domiciliary captivity in Araçatuba city, SP, as well as the occurrence of zoonosis agents in stools samples, social-economic conditions and residents-birds contact were evaluated. Results showed inadequate sanitary and nutritional management in the majority of the cases, strait contact with the parrots and lack of knowledge about parrots diseases. Salmonella was not found in stool samples while Escherichia coli was present in three samples and levedures-like structures were found in the majority them. Cryptosporidium was found in one sample. We can conclude that the close contact with the birds and the uncorrect management can favour occurrence of zoonosis in evaluated residences. The presence of Cryptosporidium sp. Indicates transmition possibility of cryptosporidiosis, in case of zoonotic specie, from parrots to humans in domiciliary captivity conditions.
7

Predicting waterfowl distribution in the central Canadian arctic using remotely sensed habitat data

Conkin, John Alexander 22 February 2011
Knowledge of a species habitat-use patterns, as well as an understanding of the distribution and spatial arrangement of preferred habitat, is essential for developing comprehensive management or conservation plans. This information is absent for many species, especially so for those living or breeding in remote areas. Habitat-use models can assist in delineating specific habitat requirements or preferences of a species. When coupled with geographic information system (GIS) technology, such models are now frequently used to identify important habitats and to better define species distributions.<p> Recent and persistent warming, widespread contaminant accumulation, and intensifying land use in the arctic heighten the urgent need for better information about spatial distributions and key habitats for northern wildlife. Here, I used aerial survey and corresponding digital land cover data to investigate breeding-ground distributions and landscape-level habitat associations of greater white-fronted geese (Anser albifrons frontalis), small Canada geese (Branta canadensis hutchinsii), tundra swans (Cygnus columbianus), king eiders (Somateria spectabilis), and long-tailed ducks (Clangula hyemalis) in the Queen Maud Gulf Migratory Bird Sanctuary and the Rasmussen Lowlands, Nunavut, Canada.<p> First, I addressed the sensitivity of inferences about predicting waterfowl presence on the basis of the amounts and configurations of arctic habitat sampled at four scales. Detection and direction of relationships of focal species with land cover covariates often varied when land cover data were analysed at different scales. For instance, patterns of habitat use for a given species at one spatial scale may not necessarily be predicted from patterns arising from measurements taken at other scales. Thus, inference based on species-habitat patterns from some scales may lead to inaccurate depictions of how habitat influences species. Potential variation in species-environment relationships relative to spatial scale needs to be acknowledged by wildlife managers to avoid inappropriate management decisions.<p> Second, I used bird presence determined during aerial surveys and classified satellite imagery to develop species-habitat models for describing breeding-ground distributions and habitat associations of each focal species. Logistic regression models identified lowland land cover types to be particularly important for the species considered. I used the Receiver Operating Characteristic (ROC) technique and the area under the curve (AUC) metric to evaluate the precision of models, where the AUC is equal to the probability that two randomly selected encounter and non-encounter survey segments will be discriminated as such by the model. In the Queen Maud Gulf, AUC values indicated reasonable model discrimination for white-fronted geese, Canada geese, and tundra swans (i.e, AUC > 0.7). Precision of species-habitat models for king eiders and long-tailed ducks was lower than other species considered, but predict encounters and non-encounters significantly better than the null model. For all species, precision of species-habitat models was lower in the Rasmussen Lowlands than in the Queen Maud Gulf, although discrimination ability remained significantly better than the null model for three of five species (king eider and long-tailed duck models performed no better than the null model here).<p> Finally, I simulated anticipated environmental change (i.e., climate warming) in the arctic by applying species-habitat models to manipulated land cover data, and then predicted distributional responses of focal species. All species considered in this research exhibited some association to lowland cover types; white-fronted geese, Canada geese, and tundra swans in particular demonstrated strong affinity toward these habitats. Others authors predict lowland cover types to be most affected by warming. Reductions of wet sedge, hummock, and tussock graminoid cover predicted in this simulation, predominantly along the coast of the Queen Maud Gulf study area and in central areas of the Rasmussen Lowlands, suggest that distributions of species dependant on these lowland habitats will be significantly reduced, if predictions about warming and habitat loss prove to be correct. Research presented here provides evidence that modeling of species distributions using landscape-level habitat data is a tractable method to identify habitat associations, to determine key habitats and regions, and to forecast species responses to environmental changes.
8

Predicting waterfowl distribution in the central Canadian arctic using remotely sensed habitat data

Conkin, John Alexander 22 February 2011 (has links)
Knowledge of a species habitat-use patterns, as well as an understanding of the distribution and spatial arrangement of preferred habitat, is essential for developing comprehensive management or conservation plans. This information is absent for many species, especially so for those living or breeding in remote areas. Habitat-use models can assist in delineating specific habitat requirements or preferences of a species. When coupled with geographic information system (GIS) technology, such models are now frequently used to identify important habitats and to better define species distributions.<p> Recent and persistent warming, widespread contaminant accumulation, and intensifying land use in the arctic heighten the urgent need for better information about spatial distributions and key habitats for northern wildlife. Here, I used aerial survey and corresponding digital land cover data to investigate breeding-ground distributions and landscape-level habitat associations of greater white-fronted geese (Anser albifrons frontalis), small Canada geese (Branta canadensis hutchinsii), tundra swans (Cygnus columbianus), king eiders (Somateria spectabilis), and long-tailed ducks (Clangula hyemalis) in the Queen Maud Gulf Migratory Bird Sanctuary and the Rasmussen Lowlands, Nunavut, Canada.<p> First, I addressed the sensitivity of inferences about predicting waterfowl presence on the basis of the amounts and configurations of arctic habitat sampled at four scales. Detection and direction of relationships of focal species with land cover covariates often varied when land cover data were analysed at different scales. For instance, patterns of habitat use for a given species at one spatial scale may not necessarily be predicted from patterns arising from measurements taken at other scales. Thus, inference based on species-habitat patterns from some scales may lead to inaccurate depictions of how habitat influences species. Potential variation in species-environment relationships relative to spatial scale needs to be acknowledged by wildlife managers to avoid inappropriate management decisions.<p> Second, I used bird presence determined during aerial surveys and classified satellite imagery to develop species-habitat models for describing breeding-ground distributions and habitat associations of each focal species. Logistic regression models identified lowland land cover types to be particularly important for the species considered. I used the Receiver Operating Characteristic (ROC) technique and the area under the curve (AUC) metric to evaluate the precision of models, where the AUC is equal to the probability that two randomly selected encounter and non-encounter survey segments will be discriminated as such by the model. In the Queen Maud Gulf, AUC values indicated reasonable model discrimination for white-fronted geese, Canada geese, and tundra swans (i.e, AUC > 0.7). Precision of species-habitat models for king eiders and long-tailed ducks was lower than other species considered, but predict encounters and non-encounters significantly better than the null model. For all species, precision of species-habitat models was lower in the Rasmussen Lowlands than in the Queen Maud Gulf, although discrimination ability remained significantly better than the null model for three of five species (king eider and long-tailed duck models performed no better than the null model here).<p> Finally, I simulated anticipated environmental change (i.e., climate warming) in the arctic by applying species-habitat models to manipulated land cover data, and then predicted distributional responses of focal species. All species considered in this research exhibited some association to lowland cover types; white-fronted geese, Canada geese, and tundra swans in particular demonstrated strong affinity toward these habitats. Others authors predict lowland cover types to be most affected by warming. Reductions of wet sedge, hummock, and tussock graminoid cover predicted in this simulation, predominantly along the coast of the Queen Maud Gulf study area and in central areas of the Rasmussen Lowlands, suggest that distributions of species dependant on these lowland habitats will be significantly reduced, if predictions about warming and habitat loss prove to be correct. Research presented here provides evidence that modeling of species distributions using landscape-level habitat data is a tractable method to identify habitat associations, to determine key habitats and regions, and to forecast species responses to environmental changes.
9

Variation in susceptibility to parasite infection: patterns, determinants and consequences in red-fronted lemurs / Variation in der Anfälligkeit für Parasiteninfektionen: Muster, Determinanten und Konsequenzen bei Rotstirnmakis

Clough, Dagmar 01 September 2009 (has links)
No description available.
10

High-Frequency Voltage Distribution Modelling of a Slotless PMSM from a Machine Design Perspective

Brauer, Patrik January 2018 (has links)
The introduction of inverters utilizing wide band-gap semiconductors allow for higher switching frequency and improved machine drive energy efficiency. However, inverter switching results in fast voltage surges which cause overvoltage at the stator terminals and uneven voltage distribution in the stator winding. Therefore, it is important to understand how next generation machine drives, with higher switching frequency, affect the voltage distribution. For this purpose, a lumped-parameter model capable of simulating winding interturn voltages for the wide frequency range of 0-10 MHz is developed for a slotless PMSM. The model includes both capacitive and inductive couplings, extracted from 2D finite element simulations, as well as analytically estimated resistive winding losses. The developed model of a single phase-winding is used to investigate how machine design aspects such as insulation materials and winding conductor distribution affects both voltage distribution and winding impedance spectrum. Validation measurements demonstrate that the model is accurate for the wide frequency range. The sensitivity analysis suggests that the winding conductor distribution affect both impedance spectrum and voltage distribution. For the slotless machine, capacitance between the winding and the stator is several times smaller than capacitance between turns. Therefore, the high-frequency effects are dominated by the capacitance between turns. Insulation materials that affect this coupling does therefore have an impact on the impedance spectrum but does not have any significant impact on the voltage distribution. / Nästa generations inverterare för styrning av elektriska maskiner, baserade på bredbandgaps komponenter, tillåter högre switchfrekvenser vilket skapar en energieffektivare drivlina. Nackdelen är att snabba spänningsflanker från den höga switchfrekvensen skapar överspänning på stators anslutningar och en ojämn spänningsfördelning i statorlindningen. Det är därför betydelsefullt att förstå hur dessa nya drivlinor påverkar lindningens spänningsfördelning. I denna rapport används en modell kapabel att simulera lindningens spänningsfördelning i det breda frekvensspektrumet 0-10 MHZ. Modellen är framtagen för en faslindning av en PMSM, utan statoröppning, som inkluderar både kapacitiva och induktiva kopplingar samt analytiskt beräknade lindningsförluster. Modellen används för att undersöka spänningsfördelningen i lindningen samt inverkan från designparametrar som isolationsmaterial och lindningsdistribution. Känslighetsanalysen visar att lindingsdistributionen har en signifikant påverkan på både impedansspektrumet och spänningsfördelningen. För den studerade maskintypen är det kapacitansen mellan varv som är dominerande för högfrekventa fenomen. Isolationsmaterial som påverkar denna koppling har en påverkan på impedansspektrumet men är liten för spänningsfördelningen.

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