The Weather Research and Forecasting model (WRF) was executed with high resolution and three nested grids of 12 km, 3 km and 1 km in the South Shetland and particularly in Deception Island s bay, during the period from 5 to 23 February 2011 at Operation Antarctica 29. Data were obtained in situ by Polar Ship Almirante Maximiano from Brazilian Navy, with a frequency of 1 h. The measured variables are pressure, temperature, dew point temperature, wind speed and direction. The model lateral and boundary conditions were data from NCEP global model, with a horizontal resolution of 1o and updated every 6 hours. Two domain sizes have been tested for the innermost grid, one with 127 and the other with 187 points in each horizontal direction. Besides, two physical configurations have been tested, with the main differences being snow microphysics and soil thermal diffusion. Pressure was the variable best represented by the model, as it is the most dependent on large scale meteorological patterns having only small dependence on the microscale. The wind direction and speed at 10 meters from the surface were also accurate, except when there were sudden fluctuations in wind speed and direction influenced by the topography, in which case there has been an underestimation of the speed. Thermodynamic variables have been very poorly represented by the small inner domain, but improved appreciably when it was expanded. The simulated temperature has an average daily cycle less intense than observed and the underestimation increases in warmer temperatures, probably caused by snow packets in the border areas. The dew point temperature daily average cycle followed the observations. Some observed and simulated patterns in circulation are briefly discussed. Finally, a simulation for a 13-day period during which there were in situ measurements at the Deception Island are presented, showing a good performance when compared to the observations. / O modelo Weather Research and Forecasting (WRF) foi rodado em alta resolução com três grades aninhadas (nesting) de 12 km, 3 km e 1 km, em Shetland do Sul e particularmente na baía da ilha Deception, durante o período de 5 a 23 de fevereiro de 2011, na Operação Antártica 29. Os dados foram medidos in situ, pelo Navio Polar Almirante Maximiano da Marinha do Brasil, com frequência de observação de 1 hora. As variáveis medidas e simuladas são pressão, temperatura, ponto de orvalho, temperatura da água do mar, velocidade e direção do vento. Para a entrada no modelo foram utilizados os dados provenientes do modelo global do National Center for Environmental Prediction (NCEP) com 1º de resolução horizontal, atualizados a cada 6 horas. Foram testadas duas opções de domínios na grade mais interna, uma com 127 e outra com 187 pontos em cada direção horizontal. Também foram consideradas duas configurações para o WRF, sendo as principais diferenças entre elas as parametrizações de microfísica de neve e difusão térmica do solo. A variável melhor representada foi a pressão na superfície, uma vez que esta depende quase que exclusivamente dos padrões meteorológicos de grande escala, tendo pequena variação na microescala. A direção e velocidade do vento a 10 m da superfície também apresentaram uma acurácia, exceto quando ocorrem flutuações bruscas na direção e velocidade do vento influenciado pela topografia próxima, ocorrendo uma subestimação na velocidade. As variáveis termodinâmicas apresentaram uma representação muito deficiente com o domínio interno menor, mas melhoraram consideravelmente quando este foi expandido. A temperatura simulada apresentou um ciclo médio diário menos intenso que o observado e a subestimativa aumenta nos períodos mais quentes, provavelmente pelos pacotes de neve nas áreas de fronteira. Já a temperatura do ponto de orvalho seguiu o ciclo diário médio das observações apresentando boas concordâncias com os dados observados. Alguns padrões observados e simulados de circulação são discutidos brevemente. Por fim, uma simulação para um período de 13 dias em que haviam medidas realizadas diretamente na Ilha Deception é apresentada, apresentando um bom desempenho.

The television advertising appropriates the characteristics of the media, to promoting, through their speeches, an identification with the public. The intensive use of technical resources of the audiovisual language propose to convert television viewers into consumers of their products, using the regional cultures. On this assumption the question that assit the study of this thesis is: What are the discursive powers of the identification process which bind the televisual advertising of Polar Beer to the Gaucho public? The reason for this study focuses on the growing importance of studies of contemporary identities and in their relation with the media and their communicative practices, especially television advertising. The choice of our analysis corpus is that, firstly, the desire to study the gaucho identity and its representation in television commercials. Thus, we chose the television commercials of Polar beer because we believe that together these features, in addition to articulating the local and global levels. To compose the object of analysis we have chosen five commercial broadcast on television between 2004 and 2010 which had the regionality of Polar beer as the main appeal of selling. Our overall research objective is to analyze the identity represented in television commercials for beer Polar to the gaucho public, and the specific objectives are: to analyze the historical and cultural context of regional identity represented in television commercials for Polar beer; understand the relationship between global and local advertising communication strategies focused on identification with local culture, and, propose a description model of advertising VT, the latter is being related to the methodology of this research. The methodology consists of four steps: data collection, decoupage in advertising script, description of the commercial in an analiyzing box with five topics and, finally, the category analysis applied to VTs advertisers. The categories are presented based on the generative trajectory of meaning of Greimas and Courtés. They are: timing, place, actorialização, figurativization and theming. For a more complete analysis we add another category: sound and verbal expression. It is organized into five chapters. The first three bring the theoretical, the fourth chapter is the definition of the corpus. The fifh and final chapter analyzes the television commercials of Polar beer. The results show that the gaucho identity appears as the element responsible for identifying the public representations by means of a carefully planned construction verbal and nonverbal from television advertising by means of expressions, planes, dialougues and characters, in which highlights: gaucho localism, masculinity, attachment to land and the traditions, and the constant excitement of what is by Rio Grande do Sul. Often the choices of advertising, materialized in its representations, end up using stereotypical symbols, making gauchidade into stuffs. Television advertising of Polar beer also promotes deterritorialization, promoting a specific cultural field experiences, opening up new duties by giving new uses to the tradition, articulating the transition from a past tradition to the present update. / A publicidade televisual apropria-se das características do meio, buscando promover, através de seus discursos, uma identificação com o público. O uso intensivo de recursos técnicos da linguagem audiovisual busca converter os telespectadores em consumidores de seus produtos, lançando mão, muitas vezes, das culturas regionais. Partindo desta premissa o estudo da presente dissertação tem como questão-problema de pesquisa a indagação: Quais são as competências discursivas do processo de identificação que vinculam a publicidade televisual da cerveja Polar ao público gaúcho? A justificativa do trabalho centra-se na crescente importância dos estudos das identidades contemporâneas e na relação desta com as mídias e suas práticas comunicacionais, especialmente a publicidade televisiva. A escolha de nosso corpus de análise deve-se, primeiramente, à vontade de se estudar a identidade gaúcha e sua representação nos comerciais televisivos. Assim, escolhemos os comerciais televisivos da cerveja Polar por acreditarmos que reúnem estas características, além de articular os níveis global e local. Para compor o objeto de análise escolhemos cinco comerciais, veiculados na televisão entre 2004 e 2010, que tinham como apelo principal de venda a regionalidade da cerveja Polar. Nosso objetivo geral de investigação consiste em analisar a identidade representada nos comerciais televisivos da cerveja Polar para o público gaúcho, tendo como objetivos específicos: analisar o contexto histórico e cultural da identidade regional representado nos comerciais televisivos da cerveja Polar; compreender a relação global e local da publicidade focado nas estratégias comunicacionais de identificação com a cultura regional e; propor um modelo de descrição de VT publicitário, estando este relacionado com a metodologia desta investigação. A metodologia consiste em quatro etapas: levantamento dos dados do audiovisual, decupagem em roteiro publicitário, descrição do comercial através de um quadro composto por cinco tópicos e, por último, a análise das categorias aplicadas aos VTs publicitários. As categorias estão baseadas nas apresentadas no percurso gerativo de sentido de Greimas e Courtés. São elas: temporalização, espacialização, actorialização, figurativização e tematização. Para uma análise mais completa adicionamos mais uma categoria: expressão sonora e verbal. A dissertação está organizada em cinco capítulos. Os três primeiros trazem o referencial teórico, o quarto capítulo é a definição do corpus e o último capítulo é as análises dos comerciais televisivos da cerveja Polar. Os resultados revelam que a identidade gaúcha aparece como o elemento responsável pela identificação do público por representações cuidadosamente planejadas através de uma construção verbal e não-verbal da publicidade televisiva por meio de expressões, planos, falas e personagens, na qual se destaca: o regionalismo gaúcho, a masculinidade, o apego a terra e às tradições e a constante exaltação do que é próprio do RS. Muitas vezes as escolhas da publicidade, materializadas em suas representações, terminam por utilizar símbolos estereotipados, tornando a gauchidade em mercadoria. A publicidade televisiva da cerveja Polar também promove disvursivamente a desterritorialização, promovendo um campo de experiências culturais específicas, possibilitando novas atribuições pelos novos usos que dá para a tradição, articulando a transição entre um passado de tradições para uma atualização do presente.

Submitted by ANA KARLA PEREIRA RODRIGUES (anakarla_@hotmail.com) on 2017-08-11T13:12:20Z No. of bitstreams: 1 arquivototal.pdf: 1245634 bytes, checksum: e10d5add0ac7fd6fd557ebc178b4b142 (MD5) / Made available in DSpace on 2017-08-11T13:12:20Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1245634 bytes, checksum: e10d5add0ac7fd6fd557ebc178b4b142 (MD5) Previous issue date: 2013-08-15 / Hesse claimed in [9] that an irreducible projective hypersurface in Pn de ned by an equation with vanishing hessian determinant is necessarily a cone. Gordan and Noether proved in [6] that this is true for n 3 and constructed counterexamples for every n 4. Gordan-Noether and Franchetta gave a classi cation of hypersurfaces in P4 with vanishing hessian and which are not cones, see [6] and [3]. Here we give a geometric approach to the classi cation proposed by Gordan-Noether, providing a classi cation of hypersurfaces with zero Hessian in P4, following the lines of Garbagnati-Reppeto in [4]. / Hesse afirmou em [9] que uma hipersuperfície projetiva irredutível em Pn definida por uma equação com hessiano nulo necessariamente é um cone. Gordan e Noether provaram em [6] que isso é verdade para n 3 e exibiram contra-exemplos para cada n 4. Gordan-Noether e Franchetta deram uma classi ca c~ao das hipersuperf cies em P4 com hessiano nulo e que n~ao s~ao cones, ver [6] e [3]. Aqui vamos dar uma abordagem geom etrica a classi ca c~ao das hipersuperf cies com hessiano nulo em P4 proposta por Gordan-Noether, seguindo as linhas de Garbagnati-Reppeto em [4].

O estudo dos nÃmeros complexos no ensino mÃdio à caracterizado, quase exclusivamente, pela abordagem algÃbrica deixando a parte geomÃtrica e suas aplicaÃÃes sem uma devida importÃncia. Este trabalho apresenta um estudo sobre nÃmeros complexos bem como algumas de suas aplicaÃÃes tanto da parte algÃbrica, aplicada a polinÃmios, quanto da parte geomÃtrica aplicada em especial à trigonometria. De inÃcio fizemos uma abordagem dos fatos histÃricos desses nÃmeros citando alguns matemÃticos que deram suas contribuiÃÃes acerca desse conjunto complexo. Em seguida à apresentada a parte teÃrica, algÃbrica e geomÃtrica, bem como algumas aplicaÃÃes a trigonometria. Por fim apresentamos a teoria das equaÃÃes algÃbricas quadrÃticas e cÃbicas e a interaÃÃo dessas com os nÃmeros complexos. / The study of the complex numbers in the medium teaching is characterized, almost exclusively, for the algebraic approach leaving the geometric part and their applications without a due importance. This work presents a study on complex numbers as well as some of their applications so much of the algebraic part, applied to polynomials, as of the geometric part especially applied to the trigonometry. Of I begin did an approach of the historical facts of those numbers mentioning some mathematical that gave their contributions near of that complex group. Soon afterwards the part theoretical, algebraic and geometric is presented, as well as some applications the trigonometry. Finally we presented the theory of the quadratic and cubic algebraic equations and the interaction of those with the complex numbers.

[pt] Baseando -se no contexto das mudanças climáticas, esta pesquisa fundamenta seus estudos na relação entre o fenômeno atmosférico da Frente Polar Atlântica (FPA) e os impactos de eventos extremos, especificamente no litoral carioca, partindo da premissa que, decorrente do aumento destes eventos frontais atmosféricos, estaria ocorrendo um consequente aumento do número de ressacas oceânicas com potenciais repercussões litorâneas negativas. O trabalho tem como objetivo identificar esta tendência dos impactos de eventos costeiros extremos sobre a linha de costa carioca a partir da análise das ocorrências históricas da expansão da Frente Fria Polar Atlântica ao longo das últimas três décadas (1988 – 2017). Para alcançar o objetivo proposto foram realizadas a aquisição de dados secundários meteorológicos, oceânicos e de registros midiáticos, baseados nas seguintes etapas: estudo numérico da frequência absoluta total da FPA (primeira etapa), assim como de ressacas significativas (segunda etapa) e eventos de impactos costeiros (terceira etapa), além da elaboração estatística do coeficiente de correlação e a frequência relativa percentual entre estes eventos (quarta etapa). Diante disto, obteve-se uma correlação positiva moderada, capaz de comprovar a hipótese desta dissertação de que há de fato uma variação numérica simultânea quanto à ocorrência das FPA s e os impactos costeiros sobre a orla carioca. Finalizando, a quinta etapa metodológica se baseou no processamento dos dados sobre a frequência histórica dos impactos costeiros, elaborando o mapa de frequência dos impactos costeiros (FIC S) no município do Rio de Janeiro (1988 – 2017), a partir do software ArcGis 10.3 e Google Earth Pro. / [en] Based on the context of climate change, this research bases its studies on the relationship between the atmospheric phenomenon of the Atlantic Polar Front (FPA) and the impacts of extreme events, specifically on the coast of Rio de Janeiro, based on the premise that, due to the increase in these frontal events atmospheric conditions, there would be a consequent increase in the number of ocean surfs with potential negative coastal repercussions. The work aims to identify this trend of the impacts of extreme coastal events on the coast of Rio de Janeiro from the analysis of the historical occurrences of the expansion of the Cold Atlantic Polar Front over the last three decades (1988 - 2017). To achieve the proposed objective, the acquisition of secondary meteorological, oceanic data and media records was carried out, based on the following steps: numerical study of the total absolute frequency of the FPA (first stage), as well as significant hangovers (second stage) and events of coastal impacts (third stage), in addition to the statistical elaboration of the correlation coefficient and the percentage relative frequency between these events (fourth stage). In view of this, a moderate positive correlation was obtained, capable of proving the hypothesis of this dissertation that there is in fact a simultaneous numerical variation as to the occurrence of FPA s and the coastal impacts on the Rio shore. Finally, the fifth methodological step was based on the processing of data on the historical frequency of coastal impacts, elaborating the frequency map of coastal impacts (FIC S) in the municipality of Rio de Janeiro (1988 - 2017), using the software ArcGis 10.3 and Google Earth Pro.

1 Ziel und Gegenstand der Untersuchungen Gegenstand der vorliegenden Arbeit war die Synthese und Charakterisierung von polaren Olefin-basierten Makromonomeren mit Hilfe von Metallocen-Katalysatoren. Polyolefine stellen eine Gruppe von Polymeren dar, die durch Additive oder chemische Veränderungen modifiziert, eine große Vielfalt von Einsatzmöglichkeiten auf der Basis einfach aufgebauter Monomere bieten. Sie stellen deshalb heutzutage die wichtigste Kunststoffgruppe dar. Ein Nachteil ist jedoch die unpolare Struktur dieser Polymere. Ziel dieser Arbeit war die Homopolymerisation polarer Olefine, um ein funktionalisiertes Polyolefin zu erzeugen, dass zudem auch als Makromonomer einsetzbar ist. Als Katalysatoren wurden im Wesentlichen die klassischen Metallocene auf Zr-Basis eingesetzt, aktiviert mit MAO. Die Makromonomere wurden im Anschluss an die Synthese umfassend charakterisiert. 2 Ergebnisse Zur Synthese wurde das bekannte 10-Undecen-1-ol (Undecenol) eingesetzt. Für eine erfolgreiche Homopolymerisation dieses Monomers ist eine effektive Abschirmung des Katalysators gegenüber der polaren Gruppe zur Minimierung der Deaktivierung des Katalysators zu gewährleisten. Für die Einführung von Schutzgruppen fand Triisobutylaluminium (TIBA) Verwendung. Auf diese Weise konnte erstmalig erfolgreich die Synthese von Polyundecenol mit Metallocen-Katalysatoren durchgeführt werden. Es zeigte sich, dass Undecenol als polares und zugleich sterisch anspruchsvolles Monomer mit der überwiegenden Anzahl der eingesetzten Metallocene schwierig zu polymerisieren ist, was im Vergleich zur Polymerisation von kurzkettigen 1 Olefinen, wie zum Beispiel Propen, anhand von geringen Molmassen (< 2000 g/mol) aber auch geringen Ausbeuten zum Ausdruck kommt. Die erzielten Molmassen der Polyundecenole sind jedoch für die Verwendung als Makromonomer vorteilhaft. Die höchsten Polymerausbeuten ermöglichte der Einsatz von ansa-Metallocenen. Mit dem Katalysator Et[Ind]2ZrCl2 konnten hierbei relative Ausbeuten im Bereich von 50 % bis 60 % bei gleichzeitig geeigneten Molmassen von < 10^4 g/mol erzielt werden. Bei der Verwendung von unverbrückten Metallocenen (bis-Cyclopentadienylkomplexe) sind die Ausbeuten und Molmassen im Vergleich zu den ansa-Metallocenen deutlich reduziert. Die synthetisierten Polyundecenole wurden hinsichtlich ihres Schmelz- und Kristallisationsverhaltens sowie der kristallinen Struktur untersucht und der Zusammenhang mit der Taktizität und der Molmasse der Polymere hergestellt. Die Ergebnisse der DSC und WAXS Untersuchungen lassen darauf schließen, dass für ataktische und isotaktische Polyundecenole eine Seitenkettenkristallisation als primäre Form der Kristallisation vorliegt. Aufgrund des hohen Gehalts von Hydroxylgruppen, die durch Wasserstoffbrückenbindungen wechselwirken, weist Polyundecenol hohe Schmelztemperaturen auf, im Vergleich mit dem unpolaren Poly(1-Undecen). So besitzt isotaktisches und auch ataktisches Polyundecenol bei vergleichbaren Molmassen eine um rund 80 K höhere Schmelztemperatur als Poly(1-Undecen). Die Wechselwirkung der Hydroxylgruppen wurde mittels FTIR-Spektroskopie nachgewiesen und liegt auch im geschmolzenen Zustand der Polymere vor. Anhand der Ergebnisse von WAXS-Untersuchungen konnte gezeigt werden, dass Polyundecenol in smektischen Schichten kristallisiert. Der Abstand zwischen den Hauptketten entspricht etwa zwei vollständig gestreckten Seitenketten des Polymers, welche orthogonal zur Hauptkette angeordnet sind. Diese Schicht-Anordnung wurde unabhängig von Molmasse und Taktizität der Polymere nachgewiesen und lässt die Schlussfolgerung zu, dass die Kristallisation isotaktischer Rückgrat-Ketten gegenüber der Seitenketten-Kristallisation unterdrückt ist. Es wurde jedoch beobachtet, dass die Taktizität einen Einfluss auf die Kristallisation hat. Polyundecenole mit isotaktischer Hauptkette weisen bei entsprechend langsamer Kristallisation eine Anordnung der Seitenketten in einer monoklinen Packung auf, was als Hinweis auf eine Kristallisation der Hauptkette interpretiert wird, auch wenn diese im Rahmen der Arbeit nicht eindeutig nachgewiesen werden konnte. Bei Polyundecenolen mit ataktischer Hauptkette ordnen sich die Seitenketten hingegen in einer hexagonalen Packung an, da die Hauptkette nicht in der Lage ist zu kristallisieren. Von besonderer Bedeutung für die Synthese der Polyundecenole waren einerseits die erzielbaren Polymerausbeuten, andererseits aber auch die Einführung geeigneter Endgruppen, welche ausschlaggebend sind für eine Nutzung als Makromonomer. Die Untersuchungen zum Polymerisationsverhalten verschiedener Metallocen-Katalysatoren zeigten, dass im Falle von ansa-Metallocenen sowie einem "CGC"-Komplex Polymere erhalten werden, die vor allem Endgruppen mit internen Doppelbindungen, doppelt- und dreifachsubstituiert, aufweisen. Solche Endgruppen sind jedoch für einen späteren Einsatz der Polymere als Makromonomer ungeeignet. Der Einsatz von unverbrückten Metallocen-Katalysatoren auf Basis der Biscyclopentadienyl-Struktur ermöglicht hingegen die Synthese von Polyundecenol mit einem hohen Anteil endständiger Vinyliden-Endgruppen zu synthetisieren. Die so erreichten Vinyliden-Endgruppenanteile bewegten sich nahezu unabhängig vom Katalysator im Bereich von etwa 85 % bis 90 %. Ein wesentliches Ergebnis der Arbeit stellt die Synthese von Polyundecenol mit Allyl-Endgruppen dar. Dieses wurde durch gezielte Kettenabbruchreaktionen mit Hilfe von Vinylchlorid erreicht. Bei Einsatz des Katalysator MBI konnten Anteile der favorisierten Allyl-Endgruppe von rund 90 % erreicht werden. Somit wurden auf diesem Wege erstmalig erfolgreich Polyundecenol-Makromonomere synthetisiert. Ein Einsatz dieser Polymere in der Copolymerisation mit Propen wurde aber durch geringe Ausbeuten verhindert. Jedoch konnte gezeigt werden, dass der Einsatz von Vinylchlorid die Synthese von Polyundecenol-Makromonomeren ermöglicht.

One of the main attractions for tourists visiting Svalbard, Norway, are polar bears. The polar bear is a vulnerable species, dependent on sea ice to survive as this is where they hunt, wander and raise their cubs. Ship-based tourism poses a number of threats mainly due to the disturbances caused by the presence of ships, damage of critical habitats and the increasing interactions and deadly conflicts between humans and polar bears. Appropriate and effective legislation based on scientific knowledge of the impacts of ship-based tourism on polar bears is necessary to ensure sustainable tourism and environmental protection. Species protection and habitat conservation is not an issue isolated to Svalbard or the polar bears but rather just one part of the pressing global issue concerning loss of biodiversity, which is one of the greatest threats to humankind. The Convention on the Conservation of European Wildlife and Natural Habitats (Bern Convention) aims to ensure the conservation of wild flora and fauna species and their habitats. At the time of signing, the Norwegian Government excluded Svalbard from the application of the Bern Convention, ensuring that national conservation policies for Svalbard would be promoted. The Svalbard Environmental Protection Act is the main act regulating environmental protection on Svalbard, including both general principles and specific provisions regarding species and habitat protection. This paper explores the various needs of the polar bear population in Svalbard and the impacts caused by ship-based tourism. The Bern Convention’s provisions relating to the identified threats posed by ship-based tourism are examined and compared with the corresponding provisions in the Svalbard Environmental Protection Act. Moreover, this paper analyses the potential benefits that could arise from the application of the Bern Convention to the Svalbard territory. This paper concludes that the protection of the polar bears could, de jure, be strengthened by the Bern Convention, mainly due to the extensive interpretation of the types of activities that should be prohibited by signatory states. However, the Bern Convention can only be enforced by non-binding mechanisms and it is therefore unlikely that the application of the convention would lead to stronger protection of the polar bears than that which is provided by national legislation. The protection of the polar bear from threats caused by ship-based tourism would therefore, de facto, most likely not be strengthened by the application of the Bern Convention.

[pt] O problema da predição das estruturas de proteínas (Protein Structure Prediction (PSP)) é um dos desafios mais importantes na biologia molecular. Pelo fato deste problema ser muito difícil, têm sido propostos diferentes modelos simplificados para resolvê-lo. Um dos mais estudados é o modelo, Hidrofóbico-Polar (HP), o modelo HP fornece uma estimativa da energia da proteína com base na soma de interações entre pares de aminoácidos hidrofóbicos (contatos H-H). Entretanto, apesar das simplificações feitas no modelo HP, o problema permanece complexo, pertencendo à classe NP-Difícil. Muitas técnicas têm sido propostas para resolver este problema entre elas, técnicas baseadas em algoritmos genéticos. Em muitos casos, as técnicas baseadas em AG foram usadas com sucesso, mas, no entanto, abordagens utilizando AG muitas vezes não tratam adequadamente as soluções geradas, prejudicando o desempenho da busca. Além disso, mesmo que eles, em alguns casos, consigam atingir o mínimo de energia conhecido para uma conformação, estes modelos não levam em conta a forma da proteína um fator muito importante na hora de obter proteínas mais compactas. Foi desenvolvido um algoritmo genético multiobjetivo para PSP no modelo HP, de modo de avaliar de forma mais eficiente, as conformações produzidas. O modelo utiliza como avaliação uma combinação baseada no número de colisões, número de contatos hidrofóbicos, compactação dos aminoácidos hidrofóbicos e hidrofílicos, obtendo, desta forma estruturas mais naturais e de mínima energia. Os resultados obtidos demonstram a eficiência desse algoritmo na obtenção de estruturas proteicas compactas providenciando indicadores da compactação dos aminoácidos hidrofóbicos e hidrofílicos da proteína. / [en] The problem of protein structured prediction (PSP) is one of the most important challenges in molecular biology. Because this problem is very difficult, different simplified models have been proposed to solve it. One of the most studied is the Hydrophobic-Polar model HP this model provides an estimate of the protein energy based on the sum of hydrophobic contacts. However, despite the simplifications made in the HP model, the problem remains complex, belonging to the class of NP-Hard problems. Many techniques have been proposed to solve this problem as genetic algorithms. In many cases the GA techniques have been used successfully, but, however, with GA approaches often do not adequately address the generated solutions, impairing the performance of the search. Furthermore, in some cases would attain the minimum energy for a known conformation, these models do not take care the protein shape, a very important factor to obtain more compact proteins. This work developed a multiobjective genetic algorithm to PSP in HP model evaluating more efficiently, the conformations produced. This model is a combination of assessment based on the collisions numbers, hydrophobic contacts, hydrophobic and hydrophilic core compression, obtaining thus more natural structures with minimum energy. The results demonstrate the efficiency of this algorithm to obtain protein structures indicators providing compact compression of the hydrophobic and hydrophilic core protein.

De nombreuses propriétés étonnantes ont été récemment découvertes à l’interface de deux perovskites isolantes l’une polaire l’autre non polaire. La discontinuité de charge à l’interface LaAlO3/SrTiO3 engendre un gas d’électron quasi-bidimensionnel qui confère un caractère métallique à cette interface. Les mécanismes locaux et la quantification des propriétés ne font pas consensus car l’interdépendance de facteurs structuraux, chimiques et électroniques complexifie la résolution du problème posé. Une catastrophe polaire, des distorsions structurales, des lacunes d’oxygène, une interdiffusion cationique et une non stœchiométrie du film ont été séparément avancées pour expliquer cette conduction. Dans le cadre d’un programme international, nous avons reçu des héterointerfaces conductrices et isolantes élaborées par ablation laser pulsé (PLD). L’origine des porteurs de charge a été recherchée par une approche globale liant procédé, structure et propriétés électriques (mesurées dans le consortium). Nous avons systématiquement analysé les interfaces en combinant imagerie à haute résolution (STEM-HAADF) et spectroscopies électroniques (EELS) et ioniques (MEIS). Une non planéité des couches atomiques, une interdiffusion cationique et un transfert d’électrons permettent de réduire la divergence de potentiel, la catastrophe polaire n’a donc pas lieu. La formation de défauts donneurs à la surface du film devient favorable au-delà d’une épaisseur critique. Les électrons sont transférés à l’interface dans la bande de conduction du STO. Nous avons mis en évidence un mécanisme de compensation concurrentiel de la charge interfaciale par des lacunes de strontium chargées négativement, qui mettent le substrat en compression plane et s’opposent au confinement 2D électrons. La variation des paramètres procédés, tels que la durée du dépôt, la pression partielle en oxygène, la température et la stœchiométrie de la plume déplace l’équilibre des différents mécanismes mis en évidence. Ce travail démontre la relation complexe liant procédé, propriétés électriques et distribution des défauts autour de ces interfaces singulières. / Novel behavior at the interface between two insulating polar/non polar perovskites has been recently discovered. The polarization discontinuity at LaAlO3/SrTiO3 drives the formation of quasi two dimensional electron gas. Both the local mechanism and quantification of such behavior remain unclear due to interplay of structural, chemical and electronic factors. Several mechanisms have been proposed, such as the polar catastrophe, structural distortions, oxygen vacancies, cationic intermixing at the interface and film non-stoichiometry. In the frame of an international project conductive and insulating heterostrucutres have been synthetized by Pulsed-Laser Deposition. In this thesis, we have developed a comprehensive approach to investigate the origin of the charge carriers. The interfaces have been systematically analyzed by combining high resolution imaging (STEM-HAADF) to atomic resolved electron (EELS) and ion (MEIS) spectroscopies. The observed and quantified parameters have been related to the electrical properties of the interfaces measured in the consortium. Buckling of the atomic layers, intermixing and electron transfer reduce the polar divergence. This rules out the polar catastrophe scenario. The formation of donor defects at the film surface is favored above a critical film thickness. Electrons are transferred to interface in the STO conduction band. A competing compensation mechanism of the positive interfacial charge by negatively charged strontium vacancies has been demonstrated that generates an in plane compression of the STO, unfavorable for a strict 2D confinement of the charges. Varying the process parameters such as growth duration, oxygen partial pressure, temperature, and plume stoichiometry shift the equilibrium of the different mechanisms highlighted. This thesis emphasizes the complex relations between the process and the properties through the defects distribution around these singular interfaces.

Nous étudions les propriétés optiques de nanostructures (Al,Ga)N/GaN crûes selon diverses orientations cristallographiques. Les orientations concernées sont : le plan non-polaire (1-100) ou plan m ; le plan semi-polaire (1-101) ou plan s ; et le plan semi-polaire (11-22). Dans un premier temps, nous nous consacrons à l'étude de l'anisotropie de la réponse optique de puits quantiques crûs selon les plans m et s. Dans un deuxième temps, nous évaluons les effets de la température sur les propriétés optiques de ces puits quantiques en utilisant la technique de photoluminescence résolue en temps qui permet d'obtenir des informations concernant les phénomènes radiatifs et non-radiatifs. S'agissant des durées de vie radiatives, nous avons mis en évidence la contribution de deux régimes de recombinaison: celui des excitons localisés, lequel est caractérisé par une durée de vie constante; et celui des excitons libres dont la durée de vie croit linéairement avec la température. Pour tous les échantillons que nous avons étudié, le régime d'excitons localisés domine à basse température alors que le régime d'excitons libres domine à haute température. Nous avons ainsi caractérisé la qualité des interfaces des puits quantiques (Al,Ga)N/GaN à partir de la détermination d'un modèle de la densité d'états de localisation. Nous trouvons qu'elle est, dans nos échantillons, encadrée par des valeurs comprises entre 10^11 - 10^12 cm-2. Notre étude montre que les puits orientés (11 22) présente la plus faible densité, et que les puits orientés selon le plan s sont les moins affectés par les phénomènes non-radiatifs. Dans un troisième temps, nous nous sommes intéressés à la caractérisation de nanostructures crûes selon le plan (11-22) pour diverses conditions de croissance. En faisant varier celles-ci, il est possible d'obtenir des boites quantiques, des fils quantiques, ou des puits quantiques. L'étude de la dynamique de recombinaison des excitons dans ces nanostructures (11-22) montre une dépendance en température de la durées de vie radiative en fonction du degré de confinement : constante pour les boîtes quantiques; proportionnelle à racine de T pour les fils ; linéaire pour les puits. Cette étude démontre la richesse de possibilités de nanostructures crûes sur des orientations non-traditionnelles elle mets en perspective de nouvelles études de croissance cristalline de nano-objets pour des applications inédites en optoélectroniques. / We study the optical properties of (Al,Ga)N/GaN nanostructures grown along several crystallographic orientations. The involved orientations are: the non-polar (1-100) plane or m-plane; the semi-polar (1-101) or s-plane; and the semi-polar (11-22) plane. First, we focus on the study of the anisotropy of the optical response of quantum wells grown in m- and s-planes. Second, we evaluate the effects of the temperature on optical properties of these quantum wells by extensive utilization of the time-resolved photoluminescence technique. It allows to obtain information regarding the evolution of radiative and non-radiative phenomena with temperature. Concerning radiative decay times, we have discriminated the contributions of two recombination regimes: the recombinations of localized excitons characterized by a constant decay time; and the recombinations of free excitons whose decay time increases linearly with the temperature. For all samples studied here, the regime of recombination of localized excitons dominates at low temperature and the regime of recombination of free excitons dominates at high temperature. In addition, we characterized the quality of (Al,Ga)N/GaN interfaces by the determination of the density of localization states. The values are ranging between 10^11 cm-2 and 10^12 cm-2 in our samples. This study demonstrates that (11-22)-oriented quantum wells exhibit the lowest density, and we find that the optical properties of s-plane oriented wells are the less impacted by the non-radiative phenomena. Third, we concentrated on the characterization of nanostructures grown along (11-22) plane direction under very different growth conditions. By modifying them, it is possible to obtain either quantum dots, or quantum wires or quantum wells. The study of the exciton recombination dynamics in these (11-22)-oriented nanostructures reveals a temperature dependence of radiative decay times correlated with the dimensions of the confining potentials: it is constant for the quantum dots; proportional to square root of T for quantum wires; and linear for quantum wells. This study demonstrates the potentialities of the nanostructures grown on non-traditional orientations for optoelectronic applications.