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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.
131

Recombination and propagation of quasiparticles in cuprate superconductors

Gedik, Nuh January 2004 (has links)
doctoral thesis, Ph.D, University of California, Berkeley, Berkeley, CA. / Published through the Information Bridge: DOE Scientific and Technical Information. "LBNL--55855" Gedik, Nuh. USDOE Director. Office of Science. Office of Basic Energy Sciences 05/20/2004. Report is also available in paper and microfiche from NTIS.
132

POSSIBILIDADES DE APRENDIZAGENS DO PROFESSOR UNIVERSITÁRIO NUMA EXPERIÊNCIA PEDAGÓGICA INTERDISCIPLINAR / ACADEMIC TEACHER S LEARNING POSSIBILITIES IN AN INTERDISCIPLINARY PEDAGOGIC EXPERIENCE

Benini, Maria Magalia Giacomini 02 October 2006 (has links)
The present work Academic Teacher s Learning Possibilities an Interdisciplinary Pedagogic Experience were developed in the Research Branch Teacher s Education of the Master's degree Course in Education of Federal University of Santa Maria (UFSM) and in the articulator discipline related to the thematic axis "Education, Times and Spaces" of the Course of Pedagogy of this Institution: PED I. Such an innovation to discipline search and the reflectivity and the complementation of the professional formation, as well as it deepens and diversifies the relative knowledge to the education. In that way, the work was mobilized concerning the formation process and the academic teacher's self-education. The investigation happened for the oral methodological ways and of the qualitative method, through the Histories of Life of five educating teachers, subjects/performers of the research, in educational exercise in PED I in the first semester of 2005. The History of Life made possible the knowledge of the education processes of those educators and the recognition of the knowledge built in their lived experiences, in a subjective and significant dimension, creating situations of learning. For the inclination of that methodology, I also built my Life History in reflection, understanding the educational experiences produced by the personal routine, for the continuous formation, for the professional development, feeling myself in an education process and self-education. In this research, I systematize, as produced results, through the narratives of the educating teachers, that PED I is a space/time knowledge sharing, of a change of experiences among the pairs, of disciplinary articulation in which the teacher is going to be constituted besides their limitations, its attempts of changes in the exercise of the profession of educating teacher. It is possible to systematize although the process of learning teaching is related to that change of behavior, as a fruit of the reflective thought to the experiences of the own profession. Before of that device it is observed that the educational experiences are knowledge, producers, and that previous experiences to the university are important and they can make the difference in the postgraduate teaching. PED I is, then, an innovative theoretical-methodological experience that can be constituted in process of learning by the educating teacher. / O trabalho Possibilidades de Aprendizagens do Professor Universitário numa Experiência Pedagógica Interdisciplinar foi desenvolvido na Linha de Pesquisa Formação de Professores do Curso de Mestrado em Educação da Universidade Federal de Santa Maria (UFSM) e na disciplina articuladora, pelo eixo temático Educação, Tempos e Espaços do Curso de Pedagogia desta Instituição: PED I. Essa inovação disciplinar busca a reflexividade e a complementação da formação profissional, bem como aprofunda e diversifica o conhecimento relativo à formação. O trabalho mobilizou-se acerca do processo de formação e autoformação do professor universitário. A investigação aconteceu pelas vias metodológicas da oralidade e do método qualitativo, através das Histórias de Vida de cinco professores formadores, sujeitos/atores da pesquisa, em exercício docente na PED I no primeiro semestre de 2005. A História de Vida possibilitou o conhecimento dos processos formativos desses formadores e o reconhecimento dos saberes construídos nas suas experiências vivenciadas, numa dimensão subjetiva e significativa, criando situações de aprendizagens. Pelo viés dessa metodologia também construí minha História de Vida em reflexão, compreendendo as experiências docentes produzidas pelo cotidiano pessoal, pela formação continuada, pelo desenvolvimento profissional, sentindo-me em processo de formação e autoformação. Nesta pesquisa, sistematizo, como resultados produzidos, através das narrativas dos professores formadores, que a PED I é um espaço/tempo de compartilhamento de saberes, de troca de experiências entre os pares, de articulação disciplinar em que vai se constituindo o professor para além das suas limitações, tentativas de mudanças no exercício da profissão de professor formador. É possível sistematizar, ainda, que o processo aprendente da docência está relacionado a essa mudança de comportamento, como fruto do pensamento reflexivo às experiências da própria profissão. Diante desse dispositivo, é visto que as experiências docentes são produtoras de saberes, e que as experiências anteriores à universidade são importantes e podem fazer a diferença na docência superior. A PED I é, então, uma experiência teórico-metodológica inovadora que pode se constituir em processo aprendente para o professor formador.
133

Films multicouches à base de nanocristaux de cellulose : relation entre structure et propriétés mécaniques et/ou optiques / Cellulose nanocrystals in multilayered films : relationships between structure and mechanical or optical properties in multilayered films

Martin, Clélia 29 September 2015 (has links)
Les nanocristaux de cellulose (NCC) sont des nanoparticules biosourcées en forme de bâtonnets produites par l’hydrolyse à l’acide sulfurique de fibres de cellulose. Les nombreux avantages des NCC (excellentes propriétés mécaniques, faible densité, grande surface spécifique, non toxicité, source abondante et renouvelable) en font des briques élémentaires particulièrement attractives pour l’élaboration de nanocomposites biosourcés et expliquent l’intérêt croissant des mondes industriels et académiques pour ces nanoparticules. Au cours des dix dernières années, les NCC ont été associés à différents types de polymère pour former, grâce à la méthode d’assemblage couche par couche, des films minces aux architectures modulables. Dans ce travail, nous avons exploré trois axes de recherche innovants dans le domaine des films multicouches à base de NCC. Dans un premier temps, les chaînes de polymère ont été remplacées par des nanoparticules inorganiques de forme hexagonale chargée positivement, les nanoplaquettes de gibbsite (GN), pour former des films minces hybrides entièrement constitués de nanoparticules. Nous avons montré que l’architecture des films (NCC/GN) pouvait être modulée sur une large gamme en ajustant les paramètres physico-chimiques comme le facteur de forme, la force ionique de la suspension de NCC ou le protocole de séchage. La caractérisation fine de la structure interne des films a été déterminée par l’utilisation de deux techniques de surface complémentaires, la microscopie à force atomique (AFM) et la réflectivité des neutrons (RN). Nous avons pu prouver que l’architecture interne des films était le résultat de différentes forces d’interaction dont la portée dépend des paramètres physico-chimiques utilisés. Dans un second temps, la résistance à l’humidité de films entièrement biosourcés a été étudiée en comparant des films dans lesquels les NCC étaient associés soit à des chaines de xyloglucane (XG) natives soit à des chaines de XG oxydées. Les résultats d’AFM et de RN révèlent que les cinétiques d’absorption d’eau et l’hydratation des films dépendent fortement de la possibilité de créer des liaisons hémiacétales intra- et intercouches générant ainsi un réseau covalent. Le troisième axe de recherche concerne la production de surfaces macroscopiques au sein desquelles les NCC seraient orientés dans des directions privilégiées pour élaborer des nanocomposites anisotropes. Un alignement prononcé a été obtenu par l’utilisation d’un flux laminaire de cisaillement.L’ajustement des paramètres structuraux confère aux films multicouches des propriétés physiques macroscopiques spécifiques. Les propriétés mécaniques des films ont donc été déterminées en utilisant la technique SIEBIMM (strain induced elastic buckling instability for mechanical measurements) et ont été reliées aux paramètres structuraux. Ces nanocomposites aux architectures et propriétés modulables pourraient permettre la conception de films minces ou de revêtements intéressants pour des domaines tels que les membranes de séparation ou les supports flexibles pour l’électronique. / CNCs are biobased nanorods that are attracting increasing attention from both the academic and industrial communities due to their numerous properties such as renewability, high specific surface area, excellent mechanical properties, light weight, or non-toxicity. CNCs are thus considered as highly promising blocks for the production of high performance biobased composites. In the last ten years, negatively charged CNCs have been associated with natural or synthetic polycations or neutral biopolymers within multilayered films built by the layer-by-layer assembly technique. In the present study, we have investigated three new research axes in the CNC-based multilayers field. In a first part, polymer chains have been replaced by positively charged inorganic Gibbsite nanoplatelets (GN) to form innovative hybrid nanoparticules-based thin films. We have shown that the architecture of (CNC/GN) films can be tuned over a wide range by adjusting the physico-chemical parameters such as the aspect ratio of the CNC, the ionic strength, or the drying protocol. The detailed internal structure of the multilayered films has been elucidated by the complementary use of AFM and neutron reflectivity (NR) and was attributed to a combination of different interaction forces. In a second part, the resistance to humidity of purely biobased films was investigated by comparing films where CNCs are associated either with neutral xyloglucan chains or with oxidized ones. AFM and NR reveal that the kinetics of water intake and hydration strongly depends on the possibility to form inter- and intra-layer hemiacetal bonds forming a covalent network. The third axis concerns the production of uniformly oriented macroscopic surfaces of CNCs to build anisotropic multilayered nanocomposites. Enhanced alignment was achieved by the use of laminar shear flow.The fine tuning of the structural features of all the multilayered systems studied gives rise to specific macroscopic physical properties. The mechanical properties of films of various architectures (Young’s modulus) have thus been measured using the strain induced elastic buckling instability for mechanical measurements (SIEBIMM) technique and tentatively related to the film’s structure. The tunable properties of such multilayered systems pave the way to the design of thin films and coatings for separation membranes or supports for flexible electronics.
134

L'invention de soi dans la littérature romantique russe / The Invention of Self in the Russian romantic literature

Subbotina, Galina 09 December 2017 (has links)
Etudier la façon dont l’individu s’exprime, se raconte et s’invente dans la littérature de l’époque romantique en Russie exige la résolution du problème posé par les spécificités du champ culturel russe. D’une part, les différents processus ou moments qui ont marqué les étapes de l’individuation en Europe occidentale (Renaissance, Réforme, Lumières) ne sont apparus dans l’histoire russe que sous des formes indirectes et affaiblies. D’autre part, les confessions auriculaires, fondamentales d’après Michel Foucault pour l’autoanalyse moderne en Europe, n’ont pas eu une grande importance dans l’Église orthodoxe russe. Enfin, les pratiques « autobiographiques » et autoréflexives en Russie restent entravées par plusieurs tabous qui émanent aussi bien des milieux intellectuels et culturels que des cercles du pouvoir. Aussi, au moment où le romantisme met à l’ordre du jour partout en Europe l’expression de soi, quelles en sont les modalités chez les écrivains russes ? En l’absence de textes autobiographiques au sens rousseauiste du terme, c’est par l’exploration des nombreuses zones d’ombre de la vie littéraire où s’épanouissait l’affirmation subjective qu’il est possible de répondre à cette question, en ayant recours à la fois à des genres « reconnus » et à des genres « mineurs », et en analysant des formes littéraires plus ou moins marginales : histoires personnelles, traductions, écriture féminine, ou encore littérature russe d’expression française. L’époque romantique, de ce point de vue, n’est pas, comme on la présente souvent dans l’histoire littéraire, un moment de passage ou de transition : il s’agit au contraire d’un moment crucial pour l’affirmation de la subjectivité dans la culture russe. / In order to study how an individual expresses and invents himself in the Russian literature of the Romantic era, it is necessary to solve the problems connected with the peculiarities of the Russian cultural field. On the one hand, the various processes that were important for individualization in Western Europe (the Renaissance, the Reformation, the Enlightenment) had in Russian history special, weakened forms. On the other hand, the secret confession, which, according to M. Foucault, is fundamental to the development of introspection in Europe, did not have much importance in the Russian Orthodox Church. In addition, autobiographical and autoreflexive practices are blocked in Russia by a variety of taboos, which are imposed by intellectual, cultural, and power circles. This raises the question of how Russian writers avoided all these limitations, when the author's self-expression had become extremely important in the European romantic literature. To answer to this question, we investigated various areas of literature, including peripheral: recognized and secondary genres, personal stories, translations, women's prose, texts written in French, etc. From this point of view, the romantic period is not just an epoch of transition, as it is often represented in the history of Russian literature, but the most important moment for affirming subjectivity in Russian culture.
135

Spectroscopie des transitions excitoniques dans des puits quantiques GaN/AlGaN / Spectroscopy of excitonic transitions in GaN/AlGaN quantum wells

Rakotonanahary, Georges 15 April 2011 (has links)
Ce travail de thèse porte sur l’étude des propriétés optiques et électroniques des puits quantiques de GaN / AlGaN grâce à des techniques classiques de réflectivité résolue en angle et de photoluminescence, ainsi qu’avec la technique de photoluminescence résolue temporellement. Les expériences de photoluminescence en régime continu ont permis d’estimer les énergies des transitions excitoniques qui sont également accessibles en réflectivité. Ces techniques ont ainsi permis de mettre en évidence l’effet Stark dans les puits quantiques GaN / AlGaN. L’effet Stark sur les énergies de transition est cohérent avec la théorie des fonctions enveloppes. Les spectres de réflectivité permettent d’accéder à la force d’oscillateur des excitons grâce à leur modélisation par le formalisme des matrices de transfert, prenant en compte les phénomènes d’élargissement homogène et inhomogènes des transitions optiques. Enfin, les mesures de photoluminescence résolue en temps en fonction de la température, ont également permis d’extraire la force d’oscillateur qui est inversement proportionnelle au temps de recombinaison radiative. Cette étude a également permis de mettre en évidence l’effet Stark responsable de la diminution de la force d’oscillateur en fonction de l’épaisseur du puits quantique mais aussi en fonction de la composition d’aluminium. L’augmentation de l’épaisseur du puits entraîne une diminution du recouvrement des fonctions d’onde, et une augmentation de la composition d’aluminium intensifie le champ électrique et diminue également le recouvrement des fonctions d’onde. / This work deals with the study of optical and electronic properties of GaN / AlGaN quantum wells, by classical techniques of spectroscopy including angle resolved reflectivity or photoluminescence, but also by time resolved photoluminescence. The continuous wave photoluminescence experiments allowed estimating the energies of the excitonic transitions, which are also available through reflectivity. These techniques highlighted the Stark effect in GaN / AlGaN quantum wells. The influence of the Stark effect on the energies of the excitonic transitions is well reproduced by envelop functions theory. Reflectivity spectra give access to the oscillator strength via their fitting by transfer matrix formalism, taking in account both homogeneous and inhomogeneous broadenings of the optical transitions. Finally, time resolved photoluminescence measurements as a function of temperature were performed to extract the oscillator strength, which is proportional to the inverse of the radiative recombination time. This technique also highlighted the Stark effect which is responsible of the vanishing of the oscillator strength with the thickness of the well and the aluminium composition. Increasing of the quantum well’s thickness induces decreasing of wave functions overlap, as well as an increasing of the aluminium composition which intensifies the electric field and splits the wave functions.
136

Forma??o de professores, saberes, reflexividade e apropria??o da cultura digital no Projeto Um Computador por Aluno (UCA) / Teacher training, knowledge, reflexivity and appropriation of digital culture at the Project One Computer per Student (UCA)

Burlamaqui, Akynara Aglae Rodrigues Santos da Silva 25 February 2014 (has links)
Made available in DSpace on 2014-12-17T14:36:40Z (GMT). No. of bitstreams: 1 AkynaraARSSB_TESE.pdf: 972888 bytes, checksum: fffd8ed8881377a2581a381ae2691619 (MD5) Previous issue date: 2014-02-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This study investigates teacher training and cognitive practice of teachers in a Basic Education school that adopted the Project One Computer per Student (OCS) in their school routine. Its relevance consists in provide directions for the continuation of training activities on the Project and guide the teachers with their pedagogical practices using the laptop model one to one. The thesis defended is that the educator formation for social using of digital media (specially the laptops from the Project UCA) gives space to establish new sociotechnical relationships, of new social and professionals practices, new identitary components and a process of reflexivity and knowledge reconstruction to teach. We reaffirm the importance of reflexivity and appropriation of digital culture for the better development of teaching practice using the Information and Communication Technologies (ICTs), giving focus to the aspects of social and professional use of the technology. The study is part of the qualitative aspect and is a procedural tracking based on principles of ethnographic research. As procedures and methodological tools, were used: intensive observation of school environments, documental analysis, focal group, semi-structured questionnaires and semi-structured individual interviews. The research was held in a public school in the city of Parnamirim - RN. The subject sample relates to 17 teachers, coming from the elementary school I and II, Youth and Adult Education and High School, who went through the process of training UCA and having entered the laptops in their teaching. The research corpus is structured based on the messages built into the process of data collection and is analyzed based on principles of Content Analysis, specified by Laurence Bardin (2011). Was taken as theoretical reference studies by Tardif (2000; 2011), Pimenta (2009), Gorz (2004, 2005), Giddens (1991), Dewey, J. (1916), Boudieu (1994; 1999), Freire (1996; 2005), among others. The analysis indicates a process of reconstruction / revision of knowledge to teach and work in digital culture, being these knowledges guided by the experience of the subjects investigated. The reconstructed knowledges will be revealed from a categorization process. The following groups of knowledges: "technical knowledges", "didactic-methodological knowledges and knowledges of professionalization" were built on the assumption of ownership of digital culture in the educational context. The analysis confirms the appearance of new ways of sociability when acquiring other forms of acting and thinking ICTs, despite the environment adverse to the reflexivity shared among the teachers. Also reveals, based on the ownership concept present on the data analysis, the construction of meanings of belonging and transformation of individuals into social routes from the interweaving of the teaching practice with the digital culture. Emphasizes, finally, the importance of a training for use of ICTs that exceeds the instrumentation, in other words, what we call "technical knowledges", but taking on its structural basis the shared reflection, the opening for the ressignificance (new meaning) and reconstruction of new knowledges and practices and that really allows, to the teacher, the living of an experience capable of providing socio-technical transformations of their relationships / Este estudo investiga a forma??o de professores e a pr?tica cognitiva dos docentes em uma escola de Educa??o B?sica que adotou o Projeto Um Computador por Aluno (UCA) em seu cotidiano escolar. Sua relev?ncia consiste em fornecer dire??es para a continua??o das a??es de forma??o do projeto e nortear o fazer e o pensar docentes junto ?s suas pr?ticas pedag?gicas com uso do laptop no modelo um para um. Defende-se que a forma??o do educador para uso social das m?dias digitais (em especial, os laptops provenientes do UCA) abre espa?os para o estabelecimento de novas rela??es sociot?cnicas, de novas pr?ticas socais e profissionais, novas perten?as identit?rias e de um processo de reflexividade e reconstru??o de saberes para ensinar. Reafirmamos a import?ncia da reflexividade e da apropria??o da cultura digital para melhor desenvolvimento da pr?tica docente com uso das Tecnologias da Informa??o e Comunica??o (TICs), enfocando os aspectos de uso social e profissional da tecnologia. O estudo alinha-se ? vertente qualitativa e trata-se de um rastreamento processual com base em princ?pios da pesquisa etnogr?fica. Como procedimentos e instrumentos metodol?gicos, foram adotados: a observa??o intensiva dos ambientes escolares, a an?lise documental, o grupo focal, question?rios semiestruturados e entrevistas individuais semiestruturadas. A pesquisa realizou-se em uma escola p?blica do munic?pio de Parnamirim RN. A amostra de sujeitos refere-se a 17 docentes, procedentes do ensino fundamental I e II, Educa??o de Jovens e Adultos e Ensino M?dio que passaram pelo processo de forma??o UCA e que inseriram os laptops em sua pr?tica pedag?gica. O corpus da pesquisa est? estruturado com base nas mensagens constru?das no processo de coleta de dados e ? analisado com base em princ?pios da An?lise de Conte?dos, especificados por Laurence Bardin (2011). Tomou-se como referencial te?rico os estudos de Tardif (2000; 2011), Pimenta (2009), Gorz (2004, 2005), Giddens (1991), Dewey, J. (1916), Boudieu (1994; 1999), Freire (1996; 2005), entre outros. A an?lise aponta um processo de reconstru??o/revis?o de saberes para ensinar e atuar na cultura digital, saberes esses pautados na experi?ncia dos sujeitos investigados. Os saberes reconstru?dos ser?o desvendados a partir de um processo de categoriza??o. Os seguintes grupos de saberes: saberes da t?cnica , saberes did?tico-metodol?gicos e saberes da profissionaliza??o foram constru?dos na premissa da apropria??o da cultura digital em contexto educacional. A an?lise confirma o surgimento de novas formas de sociabilidades ao adquirirem outras formas de agir e de pensar as TICs, apesar do ambiente adverso ? reflexibilidade compartilhada entre os docentes. Revela, ainda, com base no conceito de apropria??o presente na an?lise dos dados, a constru??o de sentidos de pertencimento e de transforma??o do sujeito no percurso social a partir do entrela?amento da pr?tica docente com a cultura digital. Ressalta, por fim, a import?ncia de uma forma??o para uso das TICs que ultrapasse a instrumentaliza??o, ou seja, o que denominamos saberes da t?cnica , mas que tenha em sua base estrutural a reflexividade compartilhada, a abertura para a ressignifica??o e (re)constru??o de saberes e fazeres e que permita realmente, ao professor, a viv?ncia de uma experi?ncia capaz de propiciar transforma??es de suas rela??es sociot?cnicas
137

Efeitos de interface em bicamadas magn?ticas acopladas

Monteiro, M?rio Antonio Alves 05 December 2008 (has links)
Made available in DSpace on 2014-12-17T15:14:47Z (GMT). No. of bitstreams: 1 MarioAAM.pdf: 4836888 bytes, checksum: 433efaa92f7e444a6422049d8ebf9384 (MD5) Previous issue date: 2008-12-05 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / We have developed a theoretical study of magnetic bilayers composed by a ferromagnetic film grown in direct contact on an antiferromagnetic one. We have investigated the interface effects in this systems due to the interfilms coupling. We describe the interface effects by a Heisenberg like coupling with an additional unidirectional anisotropy. In the first approach we assume that the magnetic layers are thick enough to be described by the bulk parameters and they are coupled through the interaction between the magnetic moments located at the interface. We use this approach to calculate the modified dynamical response of each material. We use the magnetic permeability of the layers (with corrections introduced by interface interactions) to obtain a correlation between the interface characteristics and the physical behavior of the magnetic excitations propagating in the system. In the second model, we calculated an effective susceptibility of the system considering a nearly microscopical approach. The dynamic response obtained by this approach was used to study the modifications in the spectrum of the polaritons and its consequences on the attenuated total reflection (ATR). In addition, we have calculated the oblique reflectivity. We compare our result with those obtained for the dispersion relation of the magnetostatic modes in these systems / Realizamos um estudo te?rico de bicamadas acopladas, constitu?das de um filme ferromagn?tico (F) crescido em contato direto sobre um antiferromagn?tico (AF). Investigamos os efeitos de interface nestes sistemas decorrentes do acoplamento inter-filmes. Modelamos o acoplamento atrav?s de uma intera??o tipo Heisenberg acrescida de uma anisotropia unidirecional. Em nosso estudo consideramos duas abordagens distintas: Na primeira, desenvolvemos um modelo fenomenol?gico, o qual considera que os filmes s?o espessos o bastante para serem descritos pelos seus par?metros de volume, e que est?o acoplados atrav?s da intera??o entre os momentos magn?ticos vizinhos da interface. Este modelo permitiu o c?lculo das permeabilidades magn?ticas dos filmes, modificadas pela intera??o entre estes objetos. Usamos estes resultados para estudar os modos magnetost?ticos que se propagam no sistema. O comportamento da frequ?ncia destes modos com a dire??o de propaga??o da componente do vetor de onda paralela na superf?cie, foi utilizado para investigar as modifica??es geradas pelos efeitos de interface; Na segunda abordagem, desenvolvemos o c?lculo anal?tico da suscetibilidade m?dia do sistema, utilizando um modelo quase microsc?pico. Analisamos o resultado da resposta din?mica atrav?s do c?lculo dos pol?ritons e da reflex?o total atenuada (ATR). Adicionalmente, calculamos a refletividade direta do sistema para o caso de uma radia??o incidente com dire??o arbitr?ria, a qual est? relacionada com os modos magnetost?ticos do sistema
138

Becoming savvy : developing awareness of everyday politics

Janssen, Jacqueline Jeannette Maria January 2015 (has links)
This thesis explores the experiences of an educational project manager/team leader, and at some point job-seeker, mostly in foreign countries. The focus lies, in conclusion, on developing awareness of everyday politics, brought about mainly by a significant change in the understanding of three closely related concepts: culture, language and identity. The understanding of culture developed into a notion of culture of groups - part of complex networks of other groups - simultaneously formed by and forming interdependent people who are interrelating according to evolving/emerging, explicit/implicit customs, norms, values and ethics. The exploration of language revealed patterns of conversation, common to specific groups, allowing co-creation of significant symbols, of which appropriate use enabled communication, establishment and mutual recognition. Identity became recognised as a social construct - dynamically adapting to specific local circumstances (groups), to social acts, which it forms and is formed by at the same time. In researcher's management practice and career-coaching-trajectory rather abstract and idealised text and talk describing people and/in organisations was encountered frequently, seemingly aimed at reducing the inevitable uncertainty that results from the complexity of human relating. Attention is paid to ways in which people speak and write about them-selves and/at work and how this influences the experience of self and/at work, which revealed a relation between abstract and idealised conversational patterns and impacted sense of self. The career-coaching experience in particular exposed how these conversational patterns in/and the strategic construction of 'glossy' identities (of organisations and people) do not reflect everyday perception of self and/at work, as work is developed in social interaction, of which meaning is negotiated and evolves through people's differing intentions, expectations and emerging insights; through everyday politics. Becoming 'politically savvy', acquiring awareness of everyday politics, is necessary for our functioning in organisational life. The argument is that developing 'political savvy' - becoming self-conscious in complex organisational environments where strategically co-created idealised images of self, organisations and work are common practice - is increasingly taxing, as glossy identities 'airbrush' away the messiness of everyday work life. The challenge for managers is to endeavour to see beyond these images, explicit strategies and certain conversational patterns, and develop their ability to make sense - by reflecting and taking a reflexive stance - of what it is people are doing together. Taking seriously everyday experiences may provide choice, options to proceed, possibly to develop (trust in) 'political savvy', and may increase awareness of how people adapt, change and develop (in) social acts because of and despite this.
139

Assemblage or/polymère d’épaisseur nanométrique : influence de la température sur les propriétés physiques / Gold/polymer assembly of nanometric thickness : Influence of the temperature on the physical properties

Siniscalco, David 23 September 2014 (has links)
Cette thèse s’inscrit dans une volonté de décrire l’impact de la température sur des systèmes hybrides et plus particulièrement sur un système or/polymère. L’utilisation et l’étude des propriétés de l’or en couche mince est un sujet d’actualité comme le montre le nombre important de publications chaque année (>6000). Les domaines d’applications sont nombreux en particulier dans les secteurs de l’électronique, du médical ou de l’énergie… De nombreux facteurs peuvent modifier les propriétés physiques (structure, électrique, optique) des assemblages nanométriques. Dans ce travail, nous avons choisi d’étudier l’influence sur les propriétés physiques de l’assemblage de la température du substrat lors du dépôt des couches minces d’or. Dans une première partie, les effets de la température sur la morphologie des surfaces des assemblages seront mis en évidence par une étude statistique d’images AFM. Afin de réaliser cette analyse nous avons développé une nouvelle méthode d’analyse de surface granulaire nommée - l’Interfacial Differential Function. Nous démontrerons l’efficacité de cette méthode statistique vis-à-vis des méthodes existantes en analysant différentes surfaces modèles et, en extrayant les distances caractéristiques (taille de grains, distance inter-grains). La méthode a ensuite été appliquée avec succès à l’étude de l’évolution de la morphologie de films minces d’or déposés sur silicium en fonction de la température du substrat lors du dépôt. Nous avons ainsi pu montrer que, contrairement à ce qui était décrit jusqu’ici dans la littérature, l’augmentation de la rugosité observée lorsque la température de dépôt augmente n’était pas due à une augmentation de la largeur des grains.Dans une seconde partie, nous étudierons l’évolution de la structure interne des assemblages en fonction de la température de dépôt. La forte influence des propriétés thermiques du polymère sur la structure de l’assemblage nanométrique or/polymère a été mise en évidence par réflectivité de rayons X et par microscopie électronique à transmission. La combinaison de la réflectivité de rayons x associée avec la microscopie à force atomique nous a permis de révéler l’évolution avec la température de la structure qui passe d’une structure stratifiée à basse température à une structure plus complexe de type composite avec la présence de polystyrène en surface pour les hautes températures. Dans une dernière partie, l’impact de la température sur les propriétés électriques, optiques des assemblages sera présenté. Le passage d’une surface conductrice à faible température à une surface isolante à haute température sera mis en évidence via une étude originale basée sur une cartographie de résistance électrique réalisée par AFM. Les propriétés d’exaltation optique seront quant à elles présentées à travers une étude par spectroscopie Raman.En conclusion, les résultats de ce travail seront mis en perspectives par rapport à des applications potentielles telles que l’électronique flexible ou la fabrication de capteurs. / This thesis is part of an effort to describe the impact of temperature on hybrid systems and more particularly on a gold/polymer system. The use and study of properties of gold thin film is a timely topic as evidenced by the large number of publications each year (>6000). The fields of applications are numerous especially in areas of electronics, medical or energy… Many factors can modify physical properties (structural, electrical, optical) of nanoscale assemblies. In this work, we have chosen to study the influence on physical properties of the assembly of the substrate temperature during the deposition of thin layers of gold.In the first part, effects of temperature on the surface morphology of the assemblies will become apparent from a statistical study of AFM images. To perform this analysis we have developed a new granular analysis method called IDF – Interfacial Differential Function. We will demonstrate the effectiveness of this statistical approach against the existing methods by analyzing different models and surfaces, by extracting the characteristic distances (grain size, inter-grain distance). The method has been successfully applied to the study by demonstrating changes in the morphology of thin films deposited on silicon versus the temperature of the substrate during deposition. We were able to show that, contrary to what previously described in the literature, the increased roughness observed when the deposition temperature increased, is not due to an increase in the width of the grains.In a second part, we will study the evolution of the internal structure of assemblies based on the deposition temperature. The strong influence of the thermal properties of the polymer structure on the gold/polymer nano-assembly has been shown by X-ray reflectivity and transmission electron microscopy. The combination of x-ray reflectivity associated with the atomic force microscopy has allowed us to reveal the evolution with the temperature of the structure changes from a layered structure at low temperature to a more complex structure of composite type with the presence of polystyrene on the surface for high temperatures.In the last part, the impact of temperature on optical electric properties, assemblies will be presented. The transition from a conductive surface at low temperature to a high temperature insulating surface will be highlighted via an original study based on a mapping of electrical resistance produced by AFM. Optical exaltation properties will be presented through a study by Raman spectroscopy.In conclusion, results of this work will be put in perspective with respect to potential applications such as flexible electronics and fabrication of sensors.
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Mesure des précipitations à l'aide d'un radar en bande X non-cohérent à haute résolution et d'un radar en bande K à visée verticale. Application à l'étude de la variabilité des précipitations lors de la campagne COPS / Precipitation measurement with high resolution non-coherent X-band radar and vertically pointing K-band radar. Application to the study of the variability of precipitation in the framework of COPS field campaign

Tridon, Frédéric 15 September 2011 (has links)
L’estimation quantitative des précipitations à l’échelle locale est une nécessité sociétale, à cause de l’augmentation des dégâts provoqués par des inondations exacerbées par l’urbanisation croissante. Or, des estimations locales sont particulièrement difficiles à réaliser à cause de la forte variabilité des précipitations. De plus, ce genre d’estimation est sollicité par de petits organismes tels qu’une commune, pour lesquels il n’est pas envisageable d’utiliser des instruments à la pointe de la recherche technologique à cause de leur coût prohibitif. Ainsi, il est nécessaire de développer des méthodes d’estimation quantitative des précipitations applicables à un dispositif expérimental de prix abordable. Dans ce but, un dispositif expérimental innovant est utilisé dans cette thèse. Il est constitué d’instruments de mesure directe, au sol, tels que des pluviomètres et des disdromètres, et d’un prototype de radar à balayage horizontal basé sur un radar nautique commercial, associé à un MRR (Micro Rain Radar) à visée verticale qui fournissent une estimation en altitude de la pluie, respectivement sur une surface donnée et le long d’un profil vertical. Le radar à balayage horizontal est un radar en bande X, c’est-à-dire qu’il fonctionne à une longueur d’onde lui procurant une très haute résolution radiale, mais qui est très atténuée par les précipitations. Le MRR permet d’obtenir une description précise de la microphysique des précipitations et sert de relais entre les mesures au sol et les mesures en altitude du radar en bande X. Ces deux radars étant novateurs, une grande partie de cette thèse consiste à valider leurs mesures : étalonnage, filtrage d’échos aberrants, correction de l’atténuation, etc. Une fois les mesures rendues exploitables, cette thèse se focalise sur l’étude de la variabilité des précipitations afin de proposer et développer différentes méthodes de classification, selon leur type ou leur variations locales, et de vérifier leur potentiel pour l’amélioration de l’estimation des précipitations. Les résultats montrent que cet objectif ne peut être atteint que si la qualité des mesures des radars est encore améliorée : moins d’échos parasites pour le radar en bande X et prise en compte du vent vertical pour le MRR. / Due to the increase of damage associated with floods enhanced by expanding urbanisation, the quantitative estimation of precipitation on a local scale is a societal need. However, such estimations are difficult because of the high variability of precipitation. Moreover, these estimations are requested by small organisations such as local authorities which cannot afford top level research instruments. Hence, new methods of estimation applicable to a cheap experimental set are needed. Toward this goal, an innovative experimental set is used in this work. It consists of ground instruments such as raingauges and disdrometers, and two radars, a prototype of a scanning radar based on a modified marine radar and a vertically pointing MRR (Micro Rain Radar), which give estimation of rain aloft, over an area and along a profile, respectively. The scanning radar works at X-band, meaning that it uses a longwave very attenuated by precipitation, but which provides a high range resolution. The MRR yields a detailed description of microphysics of precipitation and fills the gap between ground measurements and X-band radar measurements aloft. As both these radars are innovative, a large part of this PhD thesis was spent on the measurements validation : radar calibration, abnormal echoes filtering, attenuation consideration, etc. Using these corrected measurements, this PhD focus then on the study of the variability of precipitation, and aims to propose and develop several classification methods based on precipitation type or local variability, and to check their potential for the improvement of precipitation estimation. Results show that this goal can be reached only if the radar measurements quality is further improved : less interference echoes for the X-band radar, and consideration of vertical wind for the MRR.

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