Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-01-26T17:36:30Z No. of bitstreams: 1 ThiagoVictorRodriguesDeMedeiros_DISSERT.pdf: 3828773 bytes, checksum: a71182f41a89dc6ac4d09bef70dac843 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-01-27T21:54:39Z (GMT) No. of bitstreams: 1 ThiagoVictorRodriguesDeMedeiros_DISSERT.pdf: 3828773 bytes, checksum: a71182f41a89dc6ac4d09bef70dac843 (MD5) / Made available in DSpace on 2016-01-27T21:54:39Z (GMT). No. of bitstreams: 1 ThiagoVictorRodriguesDeMedeiros_DISSERT.pdf: 3828773 bytes, checksum: a71182f41a89dc6ac4d09bef70dac843 (MD5) Previous issue date: 2014-11-20 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / A nitreta??o por plasma vem sendo utilizada nas aplica??es industriais e tecnol?gicas em larga escala por apresentar uma melhora nas propriedades mec?nicas, tribol?gicas, dentre outras. A fim de solucionar problemas decorrentes na nitreta??o convencional, como por exemplo, os an?is de restri??o (efeito de borda), foram desenvolvidos t?cnicas com catodos diferenciados. No presente trabalho, estudou-se superf?cies de tit?nio comercialmente puro (Grau II), modificadas por tratamento de nitreta??o a plasma atrav?s de diferentes configura??es de c?todos (catodo oco, gaiola cat?dica com uma gaiola e gaiola cat?dica com duas gaiolas) variando a temperatura em 350, 400 e 430oC, com o objetivo de obter uma otimiza??o da superf?cie para aplica??es tecnol?gicas, avaliando de forma geral qual o tratamento mostrou melhores resultados no substrato. As amostras foram caracterizadas atrav?s das t?cnicas de ensaios de Microscopia de For?a At?mica (AFM), Espectroscopia Raman, Microdureza, Difra??o de Raios-X (DRX), al?m de uma an?lise macrosc?pica. Desta forma, puderam-se avaliar propriedades do tratamento como rugosidade, topografia, presen?a de elementos intersticiais, dureza, homogeneidade, uniformidade e espessura da camada nitretada. Observou-se que todas as amostras expostas a nitreta??o foram modificadas em rela??o ? amostra padr?o (sem tratamento), logo, apresentando aumento da dureza superficial, presen?a de TiN constatadas tanto por DRX como por Raman, e uma altera??o significativa na rugosidade das amostras tratadas. Constatou-se que o tratamento em c?todo oco, apesar de apresentar o menor valor de microdureza entre as amostras tratadas, foi o que apresentou a menor rugosidade superficial, apesar de nessa configura??o as amostras sofrerem uma agressividade f?sica maior do tratamento. / The plasma nitriding has been used in industrial and technological applications for large-scale show an improvement in the mechanical, tribological, among others. In order to solve problems arising in the conventional nitriding, for example, rings constraint (edge effect) techniques have been developed with different cathodes. In this work, we studied surfaces of commercially pure titanium (Grade II), modified by plasma nitriding treatment through different settings cathodes (hollow cathode, cathodic cage with a cage and cathodic cage with two cages) varying the temperature 350, 400 and 430oC, with the goal of obtaining a surface optimization for technological applications, evaluating which treatment generally showed better results under the substrate. The samples were characterized by the techniques of testing for Atomic Force Microscopy (AFM), Raman spectroscopy, microhardness, X-ray diffraction (XRD), and a macroscopic analysis. Thus, we were able to evaluate the processing properties, such as roughness, topography, the presence of interstitial elements, hardness, homogeneity, uniformity and thickness of the nitrided layer. It was observed that all samples were exposed to nitriding modified relative to the control sample (no treatment) thus having increased surface hardness, the presence of TiN observed by XRD as per both Raman and a significant change in the roughness of the treated samples . It was found that treatment in hollow cathode, despite having the lowest value of microhardness between treated samples, was presented the lowest surface roughness, although this configuration samples suffer greater physical aggressiveness of treatment

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-01-26T19:01:21Z No. of bitstreams: 1 JussierDeOliveiraVitoriano_DISSERT.pdf: 29322891 bytes, checksum: 0c0254774bc22cc8cdd1189f3829e271 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-01-28T21:34:07Z (GMT) No. of bitstreams: 1 JussierDeOliveiraVitoriano_DISSERT.pdf: 29322891 bytes, checksum: 0c0254774bc22cc8cdd1189f3829e271 (MD5) / Made available in DSpace on 2016-01-28T21:34:07Z (GMT). No. of bitstreams: 1 JussierDeOliveiraVitoriano_DISSERT.pdf: 29322891 bytes, checksum: 0c0254774bc22cc8cdd1189f3829e271 (MD5) Previous issue date: 2015-01-09 / O presente trabalho teve como objetivo analisar a resposta biol?gica em superf?cies de tit?nio modificadas por plasma de Ar+N2+H2. Discos de tit?nio grau II receberam diferentes tratamentos de superf?cie com plasma de Ar+N2+H2, constituindo sete grupos experimentais incluindo amostras apenas polidas utilizadas como padr?o. Antes e ap?s o tratamento as amostras foram caracterizadas quanto ? topografia, estrutura cristalina e molhabilidade, usando microscopia de for?a at?mica, difra??o de raios-X, espectroscopia Raman e ensaio da gota s?ssil, respectivamente. Plasma sangu?neo rico em plaquetas (PRP) foi aplicado sobre as superf?cies modificadas em placas de cultivo. Imagens obtidas por microscopia eletr?nica das plaquetas aderidas foram analisadas a fim de verificar o comportamento das plaquetas nas diferentes condi??es experimentais. Verificou-se que a adi??o de H2 na atmosfera do plasma resultou em superf?cies mais rugosas, com picos arredondados. Essas superf?cies, ao contr?rio daquelas tratadas com atmosfera de alta concentra??o de N2, s?o menos propensas ? agrega??o plaquet?ria e, consequentemente, ? forma??o de trombos quando aplicadas em dispositivos biom?dicos. / This study aimed to analyze the biological response of titanium surfaces modified by plasma Ar + N2 + H2. Titanium disks grade II received different surface treatments Ar + N2 + H2 plasma, constituting seven groups including only polished samples used as standard. Before and after treatment the samples were evaluated in terms of topography, crystal structure and wettability, using atomic force microscopy, X-ray diffraction, Raman spectroscopy and testing of the sessile drop, respectively. Rich plasma (PRP) was applied to the surfaces modified in culture plates. Images obtained by scanning electron microscopy of the adhered platelets were analyzed to verify the behavior of platelets in the different experimental conditions. We verified that the adition of H2 on plasma atmosphere resulted in more rough surfaces, with round tops. These surfaces, in contrast to that surfaces treated with high concentration of N2, are less propense to platelet aggregation and, consequently, to the formation of thrombus when applied in biomedical devices.

Made available in DSpace on 2014-12-17T15:18:07Z (GMT). No. of bitstreams: 1 JoanaCMT.pdf: 30865 bytes, checksum: 27f51c3cbcadb5a4ec7e07d9182ea1aa (MD5) Previous issue date: 2008-03-26 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / O Tit?nio (Ti) ? atualmente o material mais utilizado para fabrica??o de implantes ortop?dicos e dentais. Altera??es na superf?cie de tit?nio comercial puro (TiCP) podem determinar a reposta funcional das c?lulas, sendo um fator cr?tico para o sucesso do implante. Entretanto, a genotoxicidade de superf?cies de tit?nio tem sido pouco estudada. Deste modo, o objetivo deste trabalho foi avaliar o potencial genot?xico de uma nova superf?cie de tit?nio porosa desenvolvida por plasma comparada com uma superf?cie somente polida. Para tanto, foram realizados os ensaios cometa, aberra??es cromoss?micas (CAs) e micron?cleo (MN), utilizando c?lulas CHO-K1 (c?lulas do ov?rio de hamster Chin?s). Nossos resultados revelaram que a superf?cie de tit?nio polida foi capaz de induzir um aumento significativo dos danos no DNA, no n?mero das CAs, na tetraploidia e na freq??ncia de micron?cleos comparada ao controle. A superf?cie tratada por plasma, n?o promoveu efeito genot?xico significativo para todos os ensaios realizados. Estes resultados sugerem que a nova superf?cie de tit?nio tratada por plasma pode ser um material biologicamente seguro para sua utiliza??o em implantes ou futura aplica??o na terapia de regenera??o ?ssea-guiada, ao menos no que se refere ? sua genotoxicidade

In Axelrod's tournaments of the Prisoner's Dilemma, carried out in the 1980s, a strategy called Tit for Tat was declared the winner, and it has since then been thought of as the strategy to use to do as well as possible in different situations. In this thesis, we investigate whether Tit for Tat will still do as well if we change the game to the Hawk-Dove Game. This is done by comparing Tit for Tat to other strategies -- All C, All D, Joss and Random -- one at a time. First we analyse under which conditions each strategy will be an Evolutionary Stable Strategy, then if it is possible for a population of these two strategies to end up in a stable polymorphism, and finally, if we have a finite population instead of an infinite one, under which conditions selection will favour the fixation of each of the strategies. This leads to the conclusion that how well Tit for Tat will do depends a lot on the different conditions on the game, but in general, the more times that a pair of individuals will meet, and the higher the value of the resource is compared to the cost of fighting, the better Tit for Tat will do.

La formation des noms qui dèrivent d'un verbe n'est pas une chose simple. Ce qui rend la complexité de ce type de dérivation apparente, la mise en œuvre de plusieurs stratégies morphologiques. Notre travail sera consacré à l'étude de la structure des noms verbaux du berbère de ksar Tit n'Ali au sein du cadre théorique de la phonologie autosegmentale, et plus particulièrement du modèle CVCV (Lowenstam 1996). / This thesis contributes to the study about nouns related to verbs of the berber language spoken in Ksar Tit n’Ali (a region located on the Valley of High Guir in southern Morocco). This work aims to show, firstly, the nouns derived from verbs considered “common”or “normal” which refer to an action, in this case: action nouns, agent nouns and instrument nouns. Secondly, the verbs derived from stative verbs, especially: quality nouns and nouns we called unofficially stative nouns. As we analysed the collected informations, we found out that the existence of plenty of verbal roots and the implementation of several strategies makes this derivational operation very far from being clear. Our goal is to demonstrate the various mechanisms operated to reconcile between a - concatenative- external morphology and internal morphology -non concatenative- in order to achieve a pattern. We aim to clear the final templatic scheme that is subject to major constraints on the lexicon or the result of a morphological process. In addition, given the importance of the left site in the derivation of nominal units, we devoted a chapter to the question of the initial vowel equipment and its relationship with the passage from free status of an item to its status of annexation. Starting from the findings of predecessors and analyzing the elements of the spoken language, which is the object of our research, we realize fertility of linguistic literature in this case has not resolved our problematic completely.

La formation des noms qui dèrivent d'un verbe n'est pas une chose simple. Ce qui rend la complexité de ce type de dérivation apparente, la mise en œuvre de plusieurs stratégies morphologiques. Notre travail sera consacré à l'étude de la structure des noms verbaux du berbère de ksar Tit n'Ali au sein du cadre théorique de la phonologie autosegmentale, et plus particulièrement du modèle CVCV (Lowenstam 1996). / This thesis contributes to the study about nouns related to verbs of the berber language spoken in Ksar Tit n’Ali (a region located on the Valley of High Guir in southern Morocco). This work aims to show, firstly, the nouns derived from verbs considered “common”or “normal” which refer to an action, in this case: action nouns, agent nouns and instrument nouns. Secondly, the verbs derived from stative verbs, especially: quality nouns and nouns we called unofficially stative nouns. As we analysed the collected informations, we found out that the existence of plenty of verbal roots and the implementation of several strategies makes this derivational operation very far from being clear. Our goal is to demonstrate the various mechanisms operated to reconcile between a - concatenative- external morphology and internal morphology -non concatenative- in order to achieve a pattern. We aim to clear the final templatic scheme that is subject to major constraints on the lexicon or the result of a morphological process. In addition, given the importance of the left site in the derivation of nominal units, we devoted a chapter to the question of the initial vowel equipment and its relationship with the passage from free status of an item to its status of annexation. Starting from the findings of predecessors and analyzing the elements of the spoken language, which is the object of our research, we realize fertility of linguistic literature in this case has not resolved our problematic completely.

La formation des noms qui dèrivent d'un verbe n'est pas une chose simple. Ce qui rend la complexité de ce type de dérivation apparente, la mise en œuvre de plusieurs stratégies morphologiques. Notre travail sera consacré à l'étude de la structure des noms verbaux du berbère de ksar Tit n'Ali au sein du cadre théorique de la phonologie autosegmentale, et plus particulièrement du modèle CVCV (Lowenstam 1996). / This thesis contributes to the study about nouns related to verbs of the berber language spoken in Ksar Tit n’Ali (a region located on the Valley of High Guir in southern Morocco). This work aims to show, firstly, the nouns derived from verbs considered “common”or “normal” which refer to an action, in this case: action nouns, agent nouns and instrument nouns. Secondly, the verbs derived from stative verbs, especially: quality nouns and nouns we called unofficially stative nouns. As we analysed the collected informations, we found out that the existence of plenty of verbal roots and the implementation of several strategies makes this derivational operation very far from being clear. Our goal is to demonstrate the various mechanisms operated to reconcile between a - concatenative- external morphology and internal morphology -non concatenative- in order to achieve a pattern. We aim to clear the final templatic scheme that is subject to major constraints on the lexicon or the result of a morphological process. In addition, given the importance of the left site in the derivation of nominal units, we devoted a chapter to the question of the initial vowel equipment and its relationship with the passage from free status of an item to its status of annexation. Starting from the findings of predecessors and analyzing the elements of the spoken language, which is the object of our research, we realize fertility of linguistic literature in this case has not resolved our problematic completely.

Made available in DSpace on 2015-04-14T13:58:25Z (GMT). No. of bitstreams: 1 400633.pdf: 244771 bytes, checksum: 929e01919e85f7195f849c8c0c09bddc (MD5) Previous issue date: 2008-04-22 / Tit?nio e suas ligas s?o amplamente aplicados como materiais de implantes ortop?dicos e odontol?gicos devido a sua excelente biocompatibilidade, baixo m?dulo de elasticidade e alta resist?ncia ao desgaste e ? corros?o. Os fatores que influenciam decisivamente a adequada funcionalidade de um biomaterial s?o o crescimento do tecido ?sseo e a sua ades?o ? superf?cie do implante. Pesquisas recentes indicam que o processo de ades?o entre o implante e o tecido vivo depende da rugosidade superficial, devido ? modifica??o da sua superf?cie, e do crescimento ?sseo nesta regi?o. Essas modifica??es s?o alcan?adas principalmente com a deposi??o de revestimentos porosos por aspers?o t?rmica, a aplica??o de jateamentos com particulados cer?micos, ataques ?cidos e eletroqu?micos, entre outros. O objetivo espec?fico desta pesquisa ? estimar a osseointegra??o de filmes porosos de tit?nio em contato com a cortical ?ssea de ovinos, bem como avaliar o comportamento do processo de osseocondu??o desses filmes. O segundo objetivo ? avaliar a ades?o destes filmes porosos de tit?nio depositados sobre superf?cies modificadas de discos de tit?nio. As t?cnicas de fluoresc?ncia de raios X e espectroscopia por energia dispersiva de raios X foram aplicadas para verificar a composi??o qu?mica dos implantes, filme de tit?nio e implantes osseointegrados. A Microscopia Eletr?nica de Varredura foi usada para caracterizar a morfologia dos discos de Ti, filme de tit?nio e a interface tecido ?sseo/filme de tit?nio/metal-base. Testes de tra??o foram aplicados para avaliar a osseointegra??o dos filmes de tit?nio e a ades?o destes aos discos. Os valores de tens?o de ruptura estimados para os filmes de tit?nio s?o superiores aos verificados em discos sem revestimento poroso de tit?nio (RENZ, 2007), principalmente no per?odo de 30 dias p?s-operat?rio. Os filmes de tit?nio atacados com ?cido fluor?drico apresentaram os maiores valores de tens?o de ruptura da interface osso-filme quando comparados aos filmes somente depositados, indicando aumento da osseointegra??o. Os valores de ades?o dos filmes de tit?nio para as superf?cies modificadas s?o maiores que os valores de ades?o na superf?cie somente usinada.

Made available in DSpace on 2015-04-14T13:58:27Z (GMT). No. of bitstreams: 1 402797.pdf: 6535759 bytes, checksum: d71c96f436ffa7b29f0ee38a5038a7f7 (MD5) Previous issue date: 2008-12-14 / O processo de osseointegra??o est? fortemente ligado com as propriedades f?sicoqu?micas superficiais dos materiais utilizados em implantes. Pesquisas recentes indicam que o desenvolvimento de superf?cies texturizadas aumenta a efici?ncia deste processo, influenciando diretamente na resposta inicial das c?lulas na interface osso/implante, na taxa e na qualidade da forma??o do tecido ?sseo formado. Por?m, n?o foi verificada a melhor rela??o entre os diversos tipos de tratamentos de superf?cies e a ades?o ?ssea ao implante. O objetivo deste trabalho foi avaliar a osseointegra??o in vivo de implantes de tit?nio cil?ndricos, submetidos a diferentes tratamentos de superf?cie, atrav?s de ensaio mec?nico do tipo pull out, de acordo com a norma ASTM C 633. A morfologia superficial dos implantes foi caracterizada pelas t?cnicas de MEV e rugosimetria. A composi??o qu?mica foi avaliada pelas t?cnicas de EDS e XRF, de acordo com a norma NBR ISO 5832-2, enquanto que, para avaliar a resist?ncia ? corros?o, foi utilizada a t?cnica de Polariza??o Linear, segundo as recomenda??es da ASTM F 746. Os resultados indicaram que a composi??o qu?mica dos grupos de amostras, com exce??o do escovado, atende aos limites estipulados quanto ao teor de contaminantes presentes. Os valores de densidade de corrente indicam comportamento de passiva??o, significativamente abaixo do valor m?ximo permitido pela norma. Os testes de pull out mostraram que 30 dias de cicatriza??o foram insuficientes para se obter crescimento ?sseo satisfat?rio. De modo geral, pode-se dizer que os resultados obtidos para o grupo de 60 dias indicaram que os valores de rugosidade superficial influenciaram os valores de tens?o m?xima.

Made available in DSpace on 2015-04-14T13:58:55Z (GMT). No. of bitstreams: 1 443419.pdf: 4259691 bytes, checksum: 3fbe554be4dac8a49f70f55d940079dd (MD5) Previous issue date: 2012-08-30 / The aim of this study was to assess, in vivo, the effect of two different surface treatments of titanium implants - plasma-spray (PSA) and nano-textured plasma-spray (PSA-nano) - at the bone-to-implant interface (osseointegration), associated or not to the recombinant human growth hormone (rhGH). Twenty-four prototypes of pure titanium implants, 6-mm long and 2-mm wide, were especially fabricated in a cylindrical shape and placed in 12 New Zealand rabbit s tibiae. The implants were divided into four groups: 1) PSA implants without rhGH, 2) PSA implants with rhGH, 3) PSA-nano implants without rhGH and, lastly, 4) PSA-nano implants with rhGH. The animals were sacrificed 14 and 42 after the surgeries. Samples were collected and analysed by optical microscopy (OM), scanning electronic microscopy (SEM) and infrared microscopy (μ-FTIR), besides the pull-out mechanical test. The results showed that in the early stage of osseointegration, the recombinant human growth hormone has favored new bone formation, regardless the surface treatment. Howev-er, in the later stage, the nano-textured surface, even without the hormone, has made a positive influence on the new bone formation, when compared to its use with hormone. In this stage, only the plasma-spray surface (PSA) has been favored by the growth hormone / O objetivo deste trabalho foi avaliar, in vivo, o efeito de dois diferentes trata-mentos de superf?cie de implantes de tit?nio - plasma-spray (PSA) e plasma-spray nanotexturizado (PSA-nano) - na interface osso-implante (osseointegra??o), associ-ados ou n?o ao horm?nio do crescimento humano recombinante (rhGH). Vinte e quatro prot?tipos de implantes de tit?nio puro, medindo 6 mm de comprimento por 2 mm de di?metro, foram especialmente confeccionados em uma forma cil?ndrica e colocados na t?bia de 12 coelhos da ra?a New Zealand. Os implantes foram dividi-dos em quatro grupos: 1) implantes PSA sem rhGH, 2) implantes PSA com rhGH, 3) implantes PSA-nano sem rhGH e, por ?ltimo, 4) implantes PSA-nano com rhGH. Os animais foram sacrificados 14 e 42 dias ap?s as cirurgias. As amostras foram cole-tadas e analisadas por microscopia ?ptica (MO), microscopia eletr?nica de varredura (MEV) e microscopia de infravermelho (μ-FTIR), al?m do teste mec?nico de pull-out. Os resultados mostraram que no est?gio inicial da cicatriza??o, o horm?nio do cres-cimento recombinante humano favoreceu a neoforma??o ?ssea, independente do tipo de superf?cie. Por?m, no est?gio tardio, a nanotexturiza??o, sem a presen?a do horm?nio, exerceu uma influ?ncia positiva na neoforma??o ?ssea, quando compa-rada ao seu emprego com o horm?nio. Neste est?gio, apenas a superf?cie de plas-ma-spray (PSA) foi favorecida pelo horm?nio do crescimento