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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.
111

Na urdidura das ruínas : o percurso criativo de Douglas 'Machado em Um Corpo Subterrâneo

Vaz, Patrícia Costa 09 March 2012 (has links)
Made available in DSpace on 2016-06-02T20:23:13Z (GMT). No. of bitstreams: 1 4745.pdf: 4940680 bytes, checksum: 3d3d0fd27533d7d1e1213502821d8a07 (MD5) Previous issue date: 2012-03-09 / Universidade Federal de Minas Gerais / The research contains the study of the creative process of the documentary Um Corpo Subterrâneo (2007), of the brazilian filmmaker Douglas Machado, with the theorist horizon of the studies of process critique. The link of our analysis is the understanding of the creation as a network in process , (SALLES, 2006, p.19) and, therefore, the research proposes the dive into the creation of the documentary, going beyond the analysis of the final film. We will go through the paths of creation with the genetic dossier of the director (note books, editing script , still, edited versions, interviews, among others), and data from his biography and filmography with value to this study that allows to build hypothesis and establish possible relations between these materials and the work that resulted from these connections. Those connections that define the narrative proposal chosen by the filmmaker, that privileges the construction of the other by the memory of the grief, and that point to the poetic project of the director. / A pesquisa consiste no estudo do processo criativo do documentário Um Corpo Subterrâneo (2007), do cineasta brasileiro Douglas Machado, tendo como horizonte teórico os estudos de Crítica de Processo. O fio condutor de nossa análise é o entendimento da criação como rede em processo , (SALLES, 2006, p.19) e, assim, a pesquisa propõe o mergulho na construção do documentário, indo além da análise do filme pronto. Vamos percorrer os caminhos da criação através do dossiê genético do diretor (cadernos de anotações, roteiros de edição, still, versões editadas, entrevistas do cineasta, dentre outros), além de dados de sua biografia e filmografia pertinentes a este estudo, que nos permitem construir hipóteses e estabelecer relações possíveis entre esses materiais e a obra que resultou destas conexões. Conexões estas definidoras da proposta narrativa escolhida pelo realizador, que privilegia a construção do outro através de sua memória do luto, e que apontam para o projeto poético do diretor.
112

Bi-Lipschitz invariant geometry / Geometria Bi-Lipschitz invariante

Thiago Filipe da Silva 18 January 2018 (has links)
The study about bi-Lipschitz equisingularity has been a very important subject in Singularity Theory in last decades. Many different approach have cooperated for a better understanding about. One can see that the bi-Lipschitz geometry is able to detect large local changes in curvature more accurately than other kinds of equisingularity. The aim of this thesis is to investigate the bi-Lipschitz geometry in an algebraic viewpoint. We define some algebraic tools developing classical properties. From these tools, we obtain algebraic criterions for the bi-Lipschitz equisingularity of some families of analytic varieties. We present a categorical and homological viewpoints of these algebraic structure developed before. Finally, we approach algebraically the bi-Lipschitz equisingularity of a family of Essentially Isolated Determinantal Singularities. / O estudo da equisingularidade bi-Lipschitz tem sido amplamente investigado nas últimas décadas. Diversas abordagens têm contribuído para uma melhor compreensão a respeito. Observa-se que a geometria bi-Lipschitz é capaz de detectar grandes alterações locais de curvatura com maior precisão quando comparada a outros padrões de equisingularidade. O objetivo desta tese é investigar a geometria bi-Lipschitz do ponto de vista algébrico. Definimos algumas estruturas algébricas desenvolvendo algumas propriedades clássicas. A partir de tais estruturas obtemos critérios algébricos para a equisingularidade bi-Lipschitz de algumas classes de famílias de variedades analíticas. Apresentamos uma visão categórica e homológica dos elementos desenvol- vidos. Finalmente abordamos algebricamente a equisingularidade de famílias de Singularidades Determinantais Essencialmente Isoladas.
113

Arquitetura do Romance : estudo sobre a composição de personagens e a interferência do espaço em \"Relato de um Certo Oriente\", de Milton Hatoum / Romance Architecture : a study about characters composition and space interference in Milton Hatoum\'s \"Relato de um Certo Oriente\"

Ana Elisa Oliveira Detoni 31 October 2012 (has links)
O presente trabalho tem como objetivo buscar correspondências entre Arquitetura e Literatura, utilizando-se a obra de Milton Hatoum, \"Relato de um Certo Oriente\", como objeto da pesquisa. Procura-se empreender a leitura dos personagens de Hatoum à luz da arquitetura, a partir do espaço em que estão inseridos e onde ocorrem suas ações. A influência da cidade, da casa da infância e do local de trabalho, bem como o uso que se dá a cada lugar, são fatores que contribuem para a compreensão dos personagens que durante a obra narram-se uns aos outros. Isolados na casa ou perdidos em Manaus, no Brasil ou no mundo, os membros da família em torno da qual se desenrola este \"Relato\" relacionam-se diferentemente com o espaço do romance, cada um à sua maneira, e desta relação pode-se desenvolver uma compreensão tanto mais ampla da matriarca Emilie, de seu marido, seus filhos e da neta que se propõe narrar a história de gerações. Partindo da noção de topofilia, trata de uma área de fronteira entre arquitetura e literatura, onde as duas áreas de conhecimento podem tocar-se e nutrir-se. / This work aims to find connections between architecture and literature, using Milton Hatoum\'s book, \"Relato de um Certo Oriente\", as object to this research. It seeks read Hatoum characters through the architecture, from the space in which they live and where their actions take place. The influence of the city, the childhood home and the workplace, as well as the use that is given to each place, are factors that contribute to the understanding of the characters who during the tale tell each other history. Isolated at home or lost in Manaus, in Brazil or in the world, family members around which unfolds this \"tale\" relate differently with the space of the novel, each in its own way, and this relationship can get a broader understanding of the matriarch Emilie, her husband, her children and granddaughter who proposes to narrate the story of generations. Based on the concept of topophilia, is a border area between architecture and literature, where the two areas of knowledge can get in touch and nourish each other.
114

Uma experiência: a canção de Elomar Figueira Mello

Pessôa, Ana Cristina Moreira 10 May 2017 (has links)
Submitted by Fabiano Vassallo (fabianovassallo2127@gmail.com) on 2017-05-02T18:14:18Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Ana Cristina M Pessoa - Uma experiencia a cançao de Elomar Figueira Mello PDF.pdf: 3144810 bytes, checksum: 7649b6c98e08de4962dee0f8684190df (MD5) / Approved for entry into archive by Josimara Dias Brumatti (bcgdigital@ndc.uff.br) on 2017-05-10T18:50:08Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Ana Cristina M Pessoa - Uma experiencia a cançao de Elomar Figueira Mello PDF.pdf: 3144810 bytes, checksum: 7649b6c98e08de4962dee0f8684190df (MD5) / Made available in DSpace on 2017-05-10T18:50:08Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Ana Cristina M Pessoa - Uma experiencia a cançao de Elomar Figueira Mello PDF.pdf: 3144810 bytes, checksum: 7649b6c98e08de4962dee0f8684190df (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A presente dissertação tem como objeto central a análise do álbum Fantasia leiga para um rio seco (1981), de Elomar Figueira Mello, colocando em diálogo as diferentes linguagens de que é composto — unidades textuais, sonoras e visuais. A fim de realizar a análise crítica da obra, propõe-se uma metodologia que parte da experiência para, então, chegar a discussões mais gerais. Nesse sentido, são utilizadas análises teóricas acerca das noções de experiência, saber de experiência e experiência estética, a partir das quais são realizadas leituras-fruições do álbum. Por meio da perspectiva trazida pelas reflexões teóricas, a leitura-audição é vista como uma oscilação entre efeitos de presença e efeitos de sentido, sensorialidade e cognição, que dependerá sempre de um momento específico de intensidade, de um fruidor, uma memória, um corpo. Desse modo, o conhecimento que se busca em torno de Fantasia leiga é dinâmico, estará sempre entre o legível e o ilegível, não pretendendo, então, recuperar um significado único e estável na obra. Trata-se de um lugar do “entre”, próprio do saber da experiência aqui delimitado, o lugar do indivíduo, do sujeito, do humano. Assim, o saber procurado nesse trabalho se baseia em uma performance específica, um movimento a entrelaçar vibrações de fruidor e obra, desenhando imagens sensoriais e dinâmicas / This work has as its object the analysis of the album Fantasia leiga para um rio seco (1981), of Elomar Figueira Mello, putting in dialogue the different languages that it consists - textual units, sound and visual. In order to achieve a critical analysis of the work, we propose a methodology that begins with experience to then reach more general discussions. Therefore, we use theoretical analyzes and notions about the experience, knowledge of experience and aesthetic experience, from which the albumfruitions readings are held. Through perspective brought by theoretical considerations, the read-hearing is seen as an oscillation between presence effects and effects sense, sensuousness and cognition, which always depend on a specific moment of intensity, a spectator, a memory, a body . Thus, the knowledge that is sought about Fantasia leiga is dynamic, is always among the readable and unreadable, not intending then retrieve a unique and stable meaning. It is the place of "between" and belongs to the knowledge of experience, the place of the individual, the subject, the human. Thus, the knowledge sought in this work is based on a specific performance, a movement to connect vibrations of spectator and work, drawing sensory and dynamic images
115

Energy efficiency in glass buildings : A study about the energy efficiency of glass buildings in Stockholm and how related demands are met

Støvne, Eivind Myklebust, Vallinder, Isak Søgaard January 2020 (has links)
The building and property sector stands for one third of the final energy usage in Sweden and this should be diminished, in order to reach goals within environmental sustainability. Glass is a poor thermal insulator but nevertheless a popular choice of material when constructing new buildings. The contradiction between need of energy efficiency and the wish for “glass buildings” led to the subject of this report. This Bachelor’s thesis examines how demands on energy efficiency is met in nine glass buildings in Stockholm. Glass buildings and the current legislation is discussed from a perspective of environmental sustainability. This was done by investigating the demands stated by Boverket from a historical perspective, executing quantitative measurements of heat transfer on elected objects, and interviewing stakeholders linked to the buildings and the Swedish legislation. The study shows that the construction of glass buildings has been possible due to a restructuring of the demands on energy efficiency and technical development. It was found, in most cases, that the shares of glass were in fact lower than apparent. A larger share of glass in the building envelope required creative measures to achieve energy solutions, within legislative demands. Nevertheless, the inlet of solar radiation heat is the greatest challenge. Despite the challenges, the desire for glass is rooted in well-being and aesthetic values, which insinuate that glass buildings will be included in the cityscape henceforth. The conclusions drawn from these results are that the energy performance of glass buildings is still weaker than conventional “solid wall buildings”. Enhancement regarding insulation abilities and improvements of excluding solar radiation must be realized to strengthen the environmental sustainability of this category of buildings. / Bygg- och fastighetssektorn står för en tredjedel av den slutliga energianvändningen i Sverige, vilken måste minimeras för att nå miljömässiga hållbarhetsmål. Att bygga i glas är populärt bland moderna byggnader, trots att glas har relativt låg termisk isolationsförmåga. Motsättningen mellan behovet av energieffektivitet och efterfrågan på “glashus” skapade ämnet för denna rapport. Detta kandidatexamensarbete utforskar hur energieffektivitetskrav möts i nio olika glasbyggnader i Stockholm. Glashus och nuvarande lagstiftning diskuteras ur ett miljömässigt hållbarhetsperspektiv. Detta gjordes genom undersökningar av Boverkets krav ur ett historiskt perspektiv, kvantitativa mätningar av värmeflöden, samt intervjuer med aktörer kopplade till byggnaderna och svensk bygglagstiftning. Studien visar att byggnation av glashus har blivit möjlig på grund av en omstrukturering av energieffektivitetskraven samt teknisk utveckling. Det visade sig att andelen glas i de undersökta byggnaderna oftast var lägre än det såg ut. Större andel glas i klimatskalet krävde kreativa åtgärder för att uppnå energilösningar inom lagstiftningen. Det visade sig också att solinstrålning var den största energiutmaningen för glasbyggnaderna. Trots utmaningarna finns värden anknutna till estetik och välmående som skapar en efterfrågan på glashus, och detta leder till att glashus fortfarande kommer inkluderas i stadsmiljön framöver. En slutsats från arbetet är att energiprestandan i glasbyggnader är svagare än för konventionella “tätväggsbyggnader”. Förbättringar av glaskonstruktionen gällande isolationsförmåga och utestängning av värme från solinstrålning måste realiseras för att stärka den miljömässiga hållbarheten för denna byggnadskategori.
116

Contribution à l'évaluation de la reconfigurabilité et réorganisabilité d'un micro système de production : application à une micro-usine d'assemblage.

Descourvières, Eric 07 October 2010 (has links) (PDF)
Les travaux de thèse s‟inscrivent dans le cadre de la conception des systèmes de production/assemblage pour les produits de taille micrométrique, appelés micro-produits. Il s‟agit de produits constitués de composants de taille submillimétrique, si bien qu‟il est difficile, voire impossible, de les observer à l‟oeil nu et encore de les manipuler précisément soit directement avec les doigts, soit avec un outillage manuel. FEMTO-ST, dans son équipe SAMMI - Systèmes Automatisés de Micromanipulation et de Micro assemblage - propose des solutions robotisées pour la manipulation et l‟assemblage de ces microproduits. Ces microrobots sont conçus et réalisés pour tenir compte des forces en présence à cette échelle et les exploiter au mieux pour une manipulation dextre et précise. L‟intégration de ces microrobots pour concevoir des systèmes de production - nous traitons ici le problème du micro-assemblage - a fait émerger le concept de micro-usine. Au niveau international, nous avons pris un positionnement original en proposant une modularité non seulement au niveau des cellules de production mais également à l‟intérieur de ces cellules. Cette modularité porte à la fois sur les structures physiques mais également sur les systèmes de commande et de supervision. Dans ce manuscrit, nous proposons d‟étudier la pertinence de cette décomposition modulaire en fonction des conditions de production. Notamment, nous nous placerons dans le contexte de production changeante nécessitant réorganisation et/ou reconfiguration du système de production. Trois parties composent le travail de thèse. Nous avons établi une structure de micro-usine et une stratégie de commande dont nous avons identifié les propriétés. Nous avons ensuite formalisé une architecture des données. Enfin, l‟étude du comportement a été obtenue par simulation d‟un modèle réalisé par réseau de Petri stochastique et T-temporisé. L‟évolution stochastique se justifie par l‟incertitude inhérente au micromonde, celle-ci est d‟autant moins importante que s‟accroit la connaissance et le savoir-faire dans une situation donnée. La temporisation permet de prendre en considération les durées relatives des reconfigurations ou réorganisations qui évoluent au gré des expérimentations. Dans le cadre d‟une conception orientée objet, les modélisations sont établies au moyen du langage de modélisation graphique UML qui autorise une analyse syntaxique. Concernant les études menées avec le modèle mathématique discret de réseau de Pétri, l‟outil de simulation utilisé est PACE - IBE Simulation Engineering Gmbh -. Ce logiciel permet une programmation conditionnant les transitions grâce au langage de programmation orienté objet, SMALLTALK, pour temporiser et rendre stochastique l‟exécution du modèle. PACE comporte par ailleurs une interface graphique utilisateur souple et lisible. Les résultats de simulation sont ensuite analysés et mis en forme avec MATLAB. Ces résultats nous ont montré la pertinence de l‟approche modulaire et du choix de décomposition mis en place pour assurer de bonnes performances à une cellule de micro-assemblage.
117

Fabulário Oswald de Andrade: memórias de um homem sem profissão / Oswald de Andrade: Memories of a Man Without a Profession

Maio, Sandro Roberto 13 November 2017 (has links)
Este trabalho tem como objetivo uma leitura crítica do primeiro volume das memórias de Oswald de Andrade, intitulado Um homem sem profissão. Sob as ordens de mamãe. Memórias e confissões (1954). Esta análise interpretativa procura partir dos movimentos do narrador, por meio dos quais verifica-se a exposição dos assuntos com atenção para o contraditório, impasses e tensões presentes no relato. A fabulação narrativa que se apresenta pelos designativos de matinada e orfandade, é interpretada com base no plano subjetivo da descoberta e da perda. De outra parte, no campo das memórias e das confissões o interesse se volta para as inter-relações entre relato autobiográfico e mediações com a história brasileira. Imbricados, esses dois universos (subjetivo e coletivo) acabam por realizar um movimento de revisão de valores do artista em foco, que remonta ao próprio movimento modernista de que Oswald de Andrade foi figura central. Neste sentido, destaca-se a própria elaboração do relato de construção fragmentária, contida em episódios variados, pondo em movimento dialético as relações do narrador com a cidade, a mobilidade da viagem e a volubilidade das paixões. Daí o convívio e confronto de temas como revolução, política, sexualidade, morte e tragédia que servem para o escritor forjar o imaginário de sua juventude, numa transposição da vida como luta e da vida como arte. / This work has the objective of a critical reading of the first volume of Oswald de Andrades memories, named A men without profession. Under mommys orders. Memories and confessions (1954). This interpretative analysis leaves from the narrator moviments, wich are verified by the subjects exposition with an atention turned to contradiction, impasse and voltages that are presents in the account. The narrative fable that is presented by designatives of matinated and orphaned, is interpreted based on the subjectivity of discovery and lost. By the other way, in the memories and confessions side, the interest turns to the inter-relations in between autobiographical account and mediations with the brasilian history. Overlapped both of these universes (subjective and collective) happend to accomplish a movement of a review of the value of the artist in focus, wich goes back to the modernist movement that Oswald de Andrade was the central figure. In this sense stands out the elaboration of the account of fragmented construction, contained in various episodes, inserting in dialect movement the relations of the narrator with the city, the mobility of the travel and the volubility of the passions. Hence the conviviality and confrontation of themes as revolution, policy, sexuality, deth and tragedy, that serves to forge the imaginary of the writers youth. In a transposition of life as a fight and life as art.
118

Conversions of hydrocarbons with hydrogen over Pd model catalysts

Ludwig, Wiebke 17 January 2011 (has links)
Die Umsetzung von Kohlenwasserstoffen mit Wasserstoff auf Pd-Modellkatalysatoren wurde anhand von Molekularstrahlmethoden (MB) und IR-Spektroskopie mit Schwerpunkt auf dem Verständnis von mikroskopischen Faktoren, die die Aktivität und Selektivität bestimmen, studiert. Exemplarisch wurden die Reaktionen von cis-2-Buten mit H2(D2), cis-trans-Isomerisierung und Hydrierung, über einem geträgterten Pd/Fe3O4/Pt(1111)-Modellkatalysator und einem Pd(111)-Einkristall erforscht. Es wurde gezeigt, dass die Aktivität und Selektivität des Pd-Modellkatalysators stark von dessen Fähigkeit abhängt, ausreichend hohe Konzentrationen von H auf und in den Pd-Partikeln aufzubauen und aufrechtzuerhalten. Während Isomerisierung effektiv abläuft, wenn nur Oberflächen-H verfügbar ist, wird für die Hydrierung eine zweite Art von H-Spezies benötigt, welche mit Volumen-H assoziert ist. Kohlenstoffablagerungen auf niedrig-koordinierten Plätzen der Pd-Partikel induzieren anhaltende Hydrierung, was einer Begünstigung der H-Diffusion ins Pd-Volumen zugeschrieben wurde. Kohlenwasserstoffspezies hingegen inhibieren die Bildung von Oberflächen-H sowie noch stärker die von Volumen-H. Gepulste MB-Experimente zum H/D-Austausch zur Untersuchung der H-Verteilung zeigten, dass neben regulärem Oberflächen-H, eine zweite Art von H-Spezies, vermutlich Volumen-H, in die HD-Bildung involviert ist. C auf niedrig-koordinierten Plätzen beeinflusst die HD-Bildung vermutlich durch eine Erleichterung der H-Diffusion ins Pd-Volumen. Kohlenwasserstoffe hingegen inhibieren den H/D-Austausch. Die ersten Ergebnisse zur Adsorption und Reaktion von Isophoron, einem alpha,beta-ungesättigtem Keton, mit H2 auf einer Pd(111)-Oberfläche werden präsentiert. Veränderungen der Adsorptionsgeometrie wurden mit steigender Bedeckung und in Anwesenheit von H anhand von IRAS detektiert. In Übereinstimmung mit realistischen Katalysestudien wurde in TPR-Messungen eine deutliche Selektivität zur Hydrierung der C=C-Bindung festgestellt. / The conversion of hydrocarbons with hydrogen over well-defined Pd model catalysts has been studied using pulsed molecular beam (MB) techniques and IR spectroscopy with a special focus on the understanding of microscopic factors governing the activity and selectivity. Exemplarily, the conversion of cis-2-butene with H2(D2) toward cis-trans isomerization and hydrogenation was studied over a supported Pd/Fe3O4/Pt(111) model catalyst and a Pd(111) single crystal surface. It was found that the activity and selectivity of the Pd model catalyst depend strongly on its ability to build up and maintain a sufficiently high concentration of H on and in the Pd particles. While isomerization proceeds effectively when merely surface H is available, for hydrogenation a second hydrogen species is required that is associated with subsurface hydrogen. Carbonaceous deposits located on low-coordinated sites of the Pd particles were found to induce persisting hydrogenation activity which could be attributed to facilitation of H diffusion to subsurface sites. Hydrocarbon species, in contrast, were found to inhibit the formation of surface H and even more pronounced subsurface H. Pulsed MB experiments on the H/D exchange to probe the H distribution showed that - next to regular surface H - a second type of hydrogen species is involved in the formation of HD, most likely subsurface hydrogen. C deposited on low-coordinated sites was shown to affect the HD formation presumably by facilitating subsurface H diffusion. Hydrocarbons strongly inhibit the H/D exchange. The first results on the adsorption and reaction of isophorone, an alpha,beta-unsaturated ketone, with hydrogen over a Pd(111) single crystal surface are presented. Changes in the adsorption geometry with increasing coverage and due to co-adsorbed H were detected using IRAS. In line with realistic catalytic studies, a strong chemoselectivity toward the hydrogenation of the C=C double bond was found in TPR measurements.
119

Enhanced Raman scattering of molecular monolayers

Lin, Wan-Ing 12 April 2017 (has links)
Um hochsensitive räumliche Auflösung zu erreichen, wurden oberflächenverstärkte Raman-Spektroskopie (SERS) und spitzenverstärkte Raman-Spektroskopie (TERS) weiterentwickelt. Das grundlegende Funktionsprinzip ist jedoch noch nicht vollständig verstanden und auch Experimente dazu fehlen teilweise. In dieser Arbeit habe ich zuerst Gap-mode TERS eingesetzt, bei welcher ein starkes elektromagnetisches Feld es ermöglicht, dünne Schichten von sehr schwach streuenden Molekülen zu untersuchen. Mit der Nanometerauflösung von TERS konnte ein auf der Goldoberfläche spontan phasen-getrennten, gemischtes Thiolsystem räumlich aufgelöst werden, während STM die Nanodomänen nicht über ihre Höhenunterschiede erkennen konnte. Neue Studien deuten auf eine Raman-Verstärkung durch Graphen und Flachgold aufgrund eines chemischen Mechanismus hin. Kupfer Phthalocyanin (CuPc)-Moleküle zwischen Graphen und einer flachen Goldoberfläche erlauben Elektronenübertragungen in beide Richtungen und damit stellt sich die Frage, ob chemische Verstärkungen von SERS zueinander addiert werden können. Die Ergebnisse deuten auf eine Kopplung von den zwei einzelnen Oberflächen hin. Es wurde eine 68-fache Verstärkung von geschichtetem CuPc zwischen Graphen und Gold beobachtet, jeweils bezogen auf CuPc auf Glimmer. Zuletzt wurde mittels TERS diese Schichtstruktur untersucht. Moleküle, die sich auf der Goldoberfläche selbstanordnen und mit Graphen bedeckt worden sind, fungieren als optische Sensoren, bei welchen die Graphenverkapselung die Moleküle beschützt. Außerdem kann eine sehr hohe Raman-Verstärkung mit großer lokaler Auflösung aufgrund der kombinierten Effekte von SERS und TERS herbeigeführt werden. Die Ergebnisse zeigen, dass eine Spitze, die Graphen-verstärkte Raman-Streuung (GERS) zusätzlich um vier Größenordnungen verbessern kann, aber Gap-mode TERS abschirmt. / The quest to achieve ultrahigh sensitivity, surface specificity and high spatial resolution has led to the development of plasmon- and chemically- enhanced Raman spectroscopy, including techniques such as surface-enhanced Raman spectroscopy (SERS) and tip-enhanced Raman spectroscopy (TERS). However, a lack of fundamentally experimental demonstrations still remains. In this thesis, I firstly used gap-mode TERS, which allows studying even molecularly thin layers of very weakly scattering molecules. With the nanoscale spatial resolution provided by TERS, the spontaneous segregation in a mixed thiol system on a gold surface could be resolved, while scanning tunneling microscopy (STM) could not discern the nanodomains via their apparent height difference. Furthermore, since graphene and a flat gold surface both were known to provide some Raman enhancement through mainly a chemical mechanism, sandwiching copper phthalocyanine (CuPc) molecules between graphene and a flat gold surface allowed electrons to be transferred in both directions, and thereby to address the question whether chemical enhancements with different origins in SERS can add to each other. The results suggest that the chemical enhancements were influenced by the two individual surfaces, and a 68-fold enhancement of sandwiched CuPc between graphene and gold was observed, as compared to CuPc on mica. Last, TERS was applied to study this sandwiched structure. Molecules self-assembled on a gold surface and covered by transferred graphene acted as optical probes. Such an arrangement has interesting properties in the sense that molecules are protected and encapsulated by graphene. Also, a possible ultrahigh Raman enhancement together with localized spatial resolution may be achieved due to the combined effects from SERS and TERS. The results showed that a tip can improve graphene-enhanced Raman scattering (GERS) further by 4 orders of magnitude, but graphene exerts some shielding effect to gap-mode TERS.
120

Mergulho de produtos de esferas e suas somas conexas em codimensão 1 / Embeddings of cartesian products of spheres and its connected sums in codimension 1

Marcio Colombo Fenille 16 February 2007 (has links)
Estudamos inicialmente resultados de classificação de difeomorfismos de produtos de esferas de mesma dimensão. Tratado isto, estudamos os mergulhos suaves de produtos de três esferas, sendo a primeira de dimensão um e as demais de dimensão maior ou igual a um, com a dimensão da última maior ou igual a da segunda, em uma esfera em codimensão um, e buscamos a total caracterização do fecho das duas componentes conexas do complementar de tais mergulhos. Tratamos com enfoque especial os mergulhos do produto de três esferas de dimensão um na esfera de dimensão quatro, e, finalmente, estudamos problemas de classificação de mergulhos PL localmente não-enodados de somas conexas de toros em codimensão um. / We study initially results of classification of difeomorfisms of Cartesian products of spheres of same dimension. Treated this, we study the smooth embeddings of cartesian products of three spheres, being the first one of dimension one and excessively of bigger or equal dimension to one, with the dimension of the last equal greater or of second, in a sphere in codimension one, and search the total characterization of the latch of the two connected components of complementing of such embeddings. We deal with special approach the embeddings of the product to three spheres to dimension one in the sphere dimension four, and, finally, we study problems of classification of PL locally unknotted embeddings of connected sums of torus on codimension one.

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