Ce travail est généralement destiné à synthétiser BCPs à base d'POSS par polymérisation RAFT, à étudier leurs comportements d'auto-assemblage, à la recherche sur l'effet de POSS auto-assemblage structure sur les propriétés en vrac et à préparer nanostructuré époxy hybride par auto-assemblage de la copolymère base d’POSS. Dans le Chapitre1, Nous avons étudié la polymérisation RAFT de macromères POSS et capables de synthétiser bien définis BCPs à base d'POSS avec la fraction POSS élevé et une topologie différente tels que AB, BAB et (BA)3. Le groupe de vertex et l'effet sur la morphologie propriétés thermo-mécaniques de BCPs à base d'POSS et la relation structure-propriété ont été investigated Polymérisation RAFT dispersion dans solvant apolaire a été appliquée pour obtenir divers agrégats ayant une morphologie différente dans Chapitre2. Refroidissement de transition induite morphologie réversible a été trouvé et la sélection dans la formation des vésicules voie a été étudiée. Nano-construction de matériaux O/I époxy hybrides à base de copolymères à base d'POSS a été étudiée dans Chapitre 4. L'effet de la teneur en groupe fonctionnel sur la miscibilité de copolymère statistique base d’POSS et de l'époxy a été étudiée. Une nouvelle méthode à la technologie hybride époxy nanostructure impliquant l'auto-assemblage de BCPs à base d'POSS en résine époxy a été présenté. Homogénéité élevée et bien la taille/morphologie de contrôle de coeur-corona structure contenant coeur POSS rigide et soluble dans les réseaux corona PMMA ont été obtenus. / This work is generally aimed to synthesize POSS based BCPs via RAFT polymerization, to study their self-assembly behaviors, to research on the effect of POSS self-assembly structure on the bulk properties and to prepare nanostructured hybrid epoxy via self-assembly of POSS based copolymer. In Chapter1, We studied the RAFT polymerization of POSS macromers and capable to synthesize well defined POSS based BCPs with high POSS fraction and different topology such as AB，BAB and (BA)3. The vertex group and the morphology effect on thermo-mechanical properties of POSS based BCPs as well as the structure-property relationship was investigated. Dispersion RAFT polymerization in apolar solvent was applied and various aggregates with different morphology in Chapter2. Cooling induced reversible micelle formation and transition was found and the pathway selection in vesicle formation was investigated. Nano-construction of O/I hybrid epoxy materials based on POSS based copolymers was investigated in Chapter4. The effect of functional group content on miscibility of POSS based statistic copolymer and epoxy was investigated. A novel method to nanostructure epoxy hybrid involving self-assembly of POSS based BCPs in epoxy was presented. High homogeneity and well size/morphology control of core-corona structure containing rigid POSS core and soluble PMMA corona in networks were obtained.

Ce travail de thèse a porté sur le développement de revêtements organiques/inorganiques photopolymérisables superhydrophobes à partir de procédés d’élaboration simples associés à des produits commerciaux largement diffusés. Pour cela, des revêtements à matrice polyuréthane acrylate (PUA), intrinsèquement hydrophiles, incluant différents composés à base de silicium ont été élaborés par enduction ou pulvérisation. L’objectif a été d’apporter en surface des revêtements une structuration multi-échelle et une chimie à caractère hydrophobe nécessaires pour atteindre la superhydrophobie, c’est-à-dire un angle de contact avec l’eau supérieur à 150° et une hystérésis de mouillage inférieure à 10°. L’introduction de molécules de polysilsesquioxane polyédrique (POSS), présentant un ligand acrylate et sept ligands isobutyle, a apporté une nanostructuration et un comportement hydrophobe aux revêtements PUA à des concentrations très faibles (≤ 1% en masse.). Cependant, la rugosité apportée se révèle trop faible et cette stratégie ne peut aboutir à la superhydrophobie des revêtements. L’introduction de particules de silice pyrogénée, modifiées en surface par des chaînes polydiméthylsiloxane, a permis d’établir une structuration multi-échelle et une chimie à caractère hydrophobe à la surface des revêtements PUA, leur conférant ainsi la superhydrophobie. De plus, le procédé d’élaboration a joué un rôle majeur sur les modifications physico-chimiques de surface des revêtements : la superhydrophobie est obtenue à une concentration relativement élevée de 30 et 60% en masse de silice pyrogénée respectivement par pulvérisation et enduction. Afin de diminuer ces concentrations, la combinaison des deux stratégies précédentes, c’est-à-dire l’introduction simultanée de POSS et de silice pyrogénée, a été considérée. Ceci a permis d’exacerber le caractère hydrophobe des revêtements tout en préservant la rugosité établie par la silice pyrogénée. Cette approche a conduit à la diminution de la concentration de silice nécessaire pour obtenir la superhydrophobie dans le cas des revêtements élaborés par pulvérisation. / This work deals with the development of organic/inorganic superhydrophobic UV-curable coatings manufactured through simple processes and from commercially available products. To achieve this goal, a hydrophilic polyurethane acrylate matrix (PUA) was used, in which several silicon-based compounds were introduced. The coatings were deposited using either bar- or spray-coating. The main objective was to structure the surface thanks to a multiscale roughness, while bringing a hydrophobic character, two properties needed to obtain a superhydrophobic coating (defined by a water contact angle superior to 150° and a water contact angle hysteresis inferior to 10°). The introduction of polyhedral oligomeric silsesquioxane molecules (POSS), presenting one acrylate and seven isobutyl ligands, brought a nanostructuration and a hydrophobic behavior to PUA coatings, even at low concentrations (≤ 1%wt.). However, the roughness obtained was not sufficient to bring the superhydrophobicity to the coatings.The introduction of fumed silica particles, functionalized by PDMS chains, established multiscale roughness and hydrophobic behavior at the surface, leading to superhydrophobic coatings. Moreover, the process had a high influence on physico-chemical modifications at the coatings’surface: superhydrophobicity is obtained for a relatively high concentration of fumed silica, 30%wt. and 60%wt. respectively for spray and bar-coating. In order to decrease these concentrations, we tried the combination of the two previous strategies: introduction of POSS molecules and fumed silica particles. This path raised the hydrophobic behavior of the coatings while keeping intact the roughness brought by fumed silica particles. This approach allowed to decrease the silica concentration needed to obtain superhydrophobicity for spray-coated coatings.

<p> A recently developed surface grafting technique, surface-initiated atom transfer radical polymerization (ATRP), has the ability to directly graft polymer chains with controllable chain lengths, densities and functionalities from various kinds of surfaces. This thesis has two main focuses. First is to study the use of this technique in grafting monomers with special structures and functionalities. The other is to apply this technique to the modification of reactive metal surfaces. </p> <p> Both of fluorinated polymers and polyhedral oligomeric silsesquioxane (POSS)-containing polymers have very interesting properties. In this thesis, for the first time, a highly fluorinated monomer, 2,2,2-trifluoroethyl methacrylate (TFEMA) and a POSS-containing monomer, POSS-MA were successfully polymerized from silicon wafers by surface-initiated ATRP. This is also the first work to use this technique to graft polymers with bulky, rigid side groups. </p> <p> To achieve very high grafting density is a big challenge for surface-initiated ATRP. We designed a novel surface-attachable difunctional initiator, 11-(2,2-bis(2bromo-2-methylpropionyloxy methyl)propionyloxy) undecyltrichlorosilane. With its help, the grafting density of PTFEMA was almost doubled, from 0.48 to 0.86chains/nm2. This is so far the most effective method to increase the grafting density. </p> <p> Unlike other kinds of materials, the surfaces of metals are active in electrochemical and acid/base reactions and this reactivity complicates A TRP reactions. With the help of triethoxysilane-based initiator and mild Fe(II)/Fe(III) catalyst system, various acrylic polymers were successfully grafted from flat nickel and copper surfaces by surface-initiated ATRP. This work provided a convenient method to prepare functional polymer coatings with very stable adhesions to the metal surfaces. The same strategy can be extended to the surface modification of a shape-memory-alloy, nitinol. </p> <p> Metal nanoparticles were also modified by this technique. Polymer shells were grafted from nickel nanoparticles surfaces. After the polymer grafting, both of the dispersibility and dispersion stability of nickel nanoparticles in appropriate solvents were greatly improved. </p> / Thesis / Doctor of Philosophy (PhD)

The aim of this thesis is to investigate the discourse function of connectives in Chinese narratives. It is found that connectives , being a kind of cohesive ties , operate at different levels of discourse as boundary markers. The present study also points out that the occurrences of Chinese connectives are governed by semantic relatedness and discourse structure of the connected discourse units. Chinese connectives are classified on the basis of their meanings into four categories. In describing the positions of the four types of connectives in discourse , the author asserts that Chinese discourse is hierarchically composed of recursive micro-structures and macro-structures , with units occuring at a lower level exhibiting tighter connection. The four categories of connectives occur in discourse to link units at different levels. Additives , with the meaning of “in addition” , generally occur within topic chain to link micro-structures. Causals, which serve to connect expressions bearing causal relations , are mostly used at the connections of micro-structures and less frequently to link macro-structures. Adversatives, which mean "contrast" or "contrariness" , occur at the connections of macrostructures where discourse usually shifts to a different view point. Temporals , indicating temporal sequence , may be used either to link micro-structural expressions of events or actions or to mark shifts of the temporal settings at macro-structural level. The above findings are verified with a quantitive analysis of topic continuity which is proposed to be the indicator of semantic relatedness. The quantative analysis reveals that additives are associated with high topic continuity , and causals , adversatives and temporals are related to low continuity. The thesis also includes an experiment on empirical validity of the findings. The results of the test show that the conclusion proposed in this study adequately describes the native speakers ' competence in using Chinese connectives to organize discourse.

Ce travail de thèse porte sur la synthèse et la caractérisation d'une nouvelle classe de tensioactif hybride organiques/inorganiques POSS (Polyhedral Oligomeric SilSesquioxane) greffé poly(oxyde d'éthylène), désigné POSS-POE. Ces composés ont été utilisés comme agent tensioactif dans l'élaboration de formulations époxy-amine à base aqueuse. Parmi les différentes voies de synthèse des POSS-POE étudiées, la voie qui consiste à greffer la chaîne POE et les groupements hydrophobe par hydrosilylation de l'octa(diméthylsiloxy)-octasilsesquioxane (Q8M8H) a été privilégiée. En effet cette méthode nous a permis d'élaborer des POSS amphiphiles à balance hydrophile/hydrophobe facilement modulable. Les composés R7Q8M8-POE avec R (alkyle) de C5 à C8 et POE de 350 à 5000 g/mol ont été synthétisés et caractérisés par RMN 1H, 13C et 29Si. Des chaînes alkyle ramifiées ont été également testées comme hydrophobe afin d'évaluer l'influence de la ramification des groupements alkyle sur les propriétés des POSS POE. L'analyse des POSS POE par diffraction de rayons X aux grands angles (WAXD) a permis de mettre en évidence que les chaînes POE cristallisent selon la même structure cristalline que dans l'homopolymère POE. Même si les cages POSS sont exclues des lamelles cristallines, un ordre à courte distance entre les cages POSS avec un certain degré d'interdigitation entre les chaînes alkyle a pu être mis en évidence. Le degré d'organisation des cages POSS dépend de la longueur de la chaîne POE. La stabilité thermique des POSS POE sous air et sous azote a été étudiée par analyse thermogravimétrique (ATG). Sous azote, les cubes R7Q8M8 ont tendance à augmenter la stabilité thermique des chaînes POE de faible masse molaire (350 g/mol) mais ont un effet déstabilisant dans le cas des chaînes POE plus longues (> 350 g/mol). Sous air, les POSS POE les plus stables présentent une chaîne alkyle hydrophobe en C6. La ramification des chaînes alkyle a un effet négatif sur la stabilité thermique. Le comportement associatif des POSS POE dans l'eau a été étudié par viscosimétrie et par mesure de solubilisation de molécule sonde hydrophobe. La formation d'agrégats micellaires à partir d'une concentration comprise entre 10-4 et 4x10-4 mol/L, selon la longueur des chaînes POE et des groupements hydrophobes, a été mise en évidence. Les propriétés émulsifiantes de ces POSS POE vis-à-vis d'un prépolymère DGEBA sont comparables à un tensioactif non ionique conventionnel nonylphénoxylpolyéthoxyéthanol. Un système époxy amine à base aqueuse incorporant ces unités POSS POE a été développé. Les films réticulés obtenus présentent de bonnes propriétés thermiques et une hydrophilie de la surface nettement inférieure en comparaison des films préparés à partir de l'émulsifiant conventionnel.

Liées de façon covalente à des chaînes polymères, les nanoparticules POSS (polysilses-quioxanes polyédriques) permettent l'obtention de matériaux nanocomposites hybrides orga-nique/inorganique. Ces nanoparticules présentent deux intérêts majeurs: des dimensions bien définies (cœur inorganique: 0.5 nm), ainsi que leur caractère hybride ( groupements organiques entourant les cages inorganiques). Les nanocomposites polymère/POSS peuvent présenter un renfort important des propriétés mécaniques et de la stabilité thermique de la matrice polymère. Cependant, l'origine moléculaire de ce renfort reste mal comprise. Aussi, afin de mieux comprendre le renfort des propriétés mécaniques de la matrice, nous avons étudié l'effet des particules POSS sur l'organisation à l'état solide et la dynamique des chaînes po-lymères au sein d'une matrice semi-cristalline. Pour cela, nous avons considéré une série de copolymères polyéthylène-POSS, caractérisés par une large gamme de concentration en POSS. Le polyéthylène et le POSS ayant intrinsèquement tendance à cristalliser, les copolymères présentent des organisations à l'état solide complexes que nous avons caractérisés par l'utilisation combinée de la calorimétrie différentielle à balayage (DSC), de la diffraction des rayons X aux grands angles (DRX) et de la résonance magnétique nucléaire en phase solide (RMN). Dans un second volet de cette étude, nous nous sommes intéressés à la dynamique des chaînes de polyéthylène en phase amorphe et à l'évolution de celle-ci avec le taux de charge des nanocomposites. Enfin, nous avons également étudié, de façon sélective, la dynamique des segments de chaînes de polyéthylène situés au voisinage de la charge

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-01-26T20:11:01Z No. of bitstreams: 1 AntonioRafaelDeVasconcelosGalvaoSobrinho_DISSERT.pdf: 3127134 bytes, checksum: ba297c5607a767d19341267251ae2f9d (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-01-29T18:25:40Z (GMT) No. of bitstreams: 1 AntonioRafaelDeVasconcelosGalvaoSobrinho_DISSERT.pdf: 3127134 bytes, checksum: ba297c5607a767d19341267251ae2f9d (MD5) / Made available in DSpace on 2016-01-29T18:25:40Z (GMT). No. of bitstreams: 1 AntonioRafaelDeVasconcelosGalvaoSobrinho_DISSERT.pdf: 3127134 bytes, checksum: ba297c5607a767d19341267251ae2f9d (MD5) Previous issue date: 2014-08-22 / Barragens de rejeitos s?o estruturas que tem a finalidade de reter os res?duos s?lidos e ?gua dos processos de minera??o. Sua an?lise e planejamento iniciam com a procura do local para implanta??o, etapa na qual se deve vincular todo tipo de vari?veis que direta ou indiretamente influenciam a obra, tais como: caracter?sticas geol?gicas, hidrol?gicas, tect?nicas, topogr?ficas, geot?cnicas, ambientais, sociais, avalia??o de riscos de seguran?a, entre outras. Sendo assim, este trabalho tem como objetivo apresentar um estudo sobre o tipo de barramento mais apropriado e seguro para se projetar uma estrutura de disposi??o de rejeito de min?rio de ferro, levando-se em conta todas as vari?veis acima citadas. O estudo de caso consiste na avalia??o de s?tios para localiza??o de barragens de disposi??o de rejeitos de beneficiamento de ferro a ser constru?da na mina Bonito, no munic?pio de Jucurutu, no Serid? Potiguar. Para a sele??o do local entre as alternativas, foram considerados v?rios aspectos do estado da arte atual, aquele que causa o menor impacto ambiental, baixo custo de investimentos, agrega valor ao produto e principalmente ? seguran?a da estrutura implantada mitigando a preocupa??o com sismos induzidos e como consequ?ncia liquefa??o dos rejeitos, somatizados pelas barragens da regi?o, j? que a lavra da Mina Bonito encontra-se praticamente situada na bacia hidr?ulica da barragem Armando Ribeiro na ?rea de prote??o ambiental (APA). A metodologia utilizada compara a sismicidade induzida pelas barragens da regi?o do semi?rido com as caracter?sticas pr?prias da disposi??o de rejeitos e est?ril, levando em conta a potencializa??o da liquefa??o pela a??o da sismicidade na regi?o da Mina Bonito. Com fulcro na metodologia, indicou-se o melhor tipo de barramento para disposi??o do rejeito de min?rio de ferro ou associa??o deles, para ser projetado e constru?do no semi?rido e particularmente para a Mina Bonito. Apresenta-se, tamb?m, uma s?rie de poss?veis usos para o est?ril e rejeito em atividades de engenharia, podendo gerar beneficiamento ao bem comum / Tailings dams are structures that aims to retain the solid waste and water from mining processes. Its analysis and planning begins with searching of location for deployment, step on which to bind all kinds of variables that directly or indirectly influence the work, such as geological, hydrological, tectonic, topographic, geotechnical, environmental, social characteristics, evaluation security risks, among others. Thus, this paper aims to present a study on the most appropriate and secure type of busbar to design a layout structure of iron ore tailings, taking into account all the above mentioned variables. The case study involves the assessment of sites for location of dams of tailings disposal beneficiation of iron mine to be built in Bonito, in the municipality of Jucurutu in Serid? Potiguar. For site selection among alternatives, various aspects of the current state of the art were considered, one that causes the least environmental impact, low cost investment, adding value to the product and especially the safety of the implanted structure mitigates the concern about induced earthquakes as a result of liquefaction wastes somatized by dams in the region, as the tilling of Mina Bonito is located practically in the hydraulic basin dam Armando Ribeiro in environmental protection (APA). The methodology compares induced by dams in the semiarid region with the characteristics of the waste disposal and sterile seismicity, taking into account the enhancement of liquefaction by the action of seismicity in the Mina Bonito region. With the fulcrum in the methodology, we indicated the best busbar type for disposal of tailings from iron ore or combination of them, to be designed and built in semiarid particularly for Mina Bonito. Also presents a number of possible uses for the tailings and in engineering activities, which may cause processing to the common good.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-02-20T22:47:57Z No. of bitstreams: 1 DarioGuedesMirandaDeAssuncao_DISSERT.pdf: 5531425 bytes, checksum: ce1be7a5114d5ab1a80f64312a354e13 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-02-24T21:16:57Z (GMT) No. of bitstreams: 1 DarioGuedesMirandaDeAssuncao_DISSERT.pdf: 5531425 bytes, checksum: ce1be7a5114d5ab1a80f64312a354e13 (MD5) / Made available in DSpace on 2017-02-24T21:16:57Z (GMT). No. of bitstreams: 1 DarioGuedesMirandaDeAssuncao_DISSERT.pdf: 5531425 bytes, checksum: ce1be7a5114d5ab1a80f64312a354e13 (MD5) Previous issue date: 2016-09-23 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A pesquisa e desenvolvimento de t?cnicas cada vez mais eficientes de estimula??o de reservat?rios de hidrocarbonetos, que j? n?o s?o economicamente vi?veis devido ? baixa permeabilidade relativa, atrav?s de faturamento hidr?ulico alavancaram os ?ndices de produ??o mundial nos ?ltimos anos. O monitoramento de eventos micross?smicos, gerados nesse ambiente de produ??o, pode fornecer informa??es importantes a respeito do reservat?rio. A aplica??o do monitoramento micross?smico, relacionado ? inje??o de fluidos (hidrofraturamento), est? sendo cada vez mais recorrente na ind?stria de petr?leo, devido ? capacidade destas informa??es auxiliarem no desenvolvimento do reservat?rio, na decis?o de posicionamento de novas inje??es de fluidos, localiza??o de novas perfura??es, etc. O desenvolvimento e aperfei?oamento de m?todos no monitoramento micross?smico ? uma importante alternativa de pesquisa para auxiliar o desenvolvimento de campos produtores, devido ? aus?ncia de m?todos que apresentem baixo custo e ent?o viabilize a sua utiliza??o em campos de baixa produ??o. Desta forma, propomos neste trabalho uma an?lise de viabilidade computacional e efici?ncia na utiliza??o da t?cnica SSA com poss?vel identificador de onda ?P?, para poss?vel utiliza??o em monitoramento de eventos micross?smicos em ambientes com opera??es de fraturamento hidr?ulico. O processamento computacional foi dividido em tr?s fases, duas com testes em dados sint?ticos e uma com aplica??o em dados reais de tiro de canhoneio. Na primeira fase de testes sint?ticos analisou-se os erros de posicionamento e erros de tempo de origem de um evento (com posi??o real em x=0, y=0 e z=-1km) com 3 e 8 receptores (geometria diferente do dado real), para diferentes dados e par?metros de entrada, por exemplo, dado sem ru?do, dado com ru?do (2, 5 ,10, 20, 30 e 40%), diferentes janelas de RPA/LPA, diferentes quantidades de receptores, etc. Na segunda fase de testes sint?ticos analisou-se os erros de posicionamento de um evento (com posi??o real em x=0, y=0 e z=-0,7km) com 3 e 12 receptores (geometria similar ao dado real), para um ?nico dado com ru?do aleat?rio de 40% e diferentes janelas de RPA/LPA. E na fase de aplica??o em dados reais (13 diferentes eventos posicionados em x=0, y=0 e Z=diferentes profundidades) as analises foram feitas com rela??o aos resultados de posicionamento de cada evento e os tempos de origem encontrados para cada um deles, utilizando uma ?nica janela RPA/LPA. / The research and development of techniques of stimulation of oil reservoirs, that are no longer economically viable due to the low relative permeability, through of hydraulic fracturing, leveraged world production rates in recent years. The monitoring microseismics events, generated in this production environment, can provide important information about the reservoir. The application of microseismic monitoring, related to the injection of fluids, is being increasingly recurrent in the oil industry due to the capacity of this information assist in the development of the reservoir, the placement decision of new injections of fluid, location of new perforations, among others. The development and improvement of methods in microseismic monitoring is an important alternative of search for help in the development of producing oil fields, due to lack of methods that have low cost and so makes possible its use in fields low production. Thus, we propose in this paper an analysis of the computational viability and efficient in the use of the technical SSA with possible P-wave identifier, for possible use in monitoring microseismic events in environments with hydraulic fracturing operations. The computational processing was divided into three phases, two with synthetic data tests and one with real data application of perforating shot (cannonade shot). In the first phase of synthetic tests were analyzed positioning errors and origin time errors of an event (with real position at x = 0, y = 0 and z = -1km) with 3 and 08 receptors (different geometry of the real data) for different data and input parameters, for example, data without noise, data with noise (2, 5, 10, 20, 30 and 40%), different windows RPA/LPA, different amounts receptors, etc. In the second phase synthetic test were analyzed the positioning errors of an event (with real position x = 0, y = 0 and z = -0,7km) with 3 and 12 receptors (geometry similar to the real data), for only a data with random noise of 40% and different windows of RPA/LPA. And in the phase of real data test (13 different events positioned at x = 0, y = 0 and Z = different depths) analyzes were made with respect the results for event each positioning and origin times found for each event, using only one RPA/LPA window.

No description available.

No description available.