In this master s thesis, we have studied the possibility of Lorentz invariance violation by considering some terms of the standard-model extesion (SME), specifically, those terms which refer to the quantum electrodynamics extension. We have performed quantum corrections in the fermionic sector of the usual quantum electrodynamics with added terms which violate the Lorentz and CPT symmetries in two different configurations. Firstly, adding operators governed by the coefficient gκλμ and, in a later time, adding operators governed by the coefficient bμ. In the theory with the coefficient gκλμ, we have performed quantum corrections in order to induce, in the bosonic sector of the theory, the conventional Chern-Simons and the higher-derivative terms, and analyze the behavior of both terms in the finite temperature regime, by using the method of derivative expansion and the Matsubara formalism. On the other hand, in the model with the coefficient bμ, we have performed quantum corrections in order to induce, in the bosonic sector, the higher-derivative Chern-Simons term, by using the method of derivative expansion and, subsequently, analyze the behavior of this term in the finite temperatura regime, where we have used the Matsubara formalism again. Thus, for the first case, we have observed that the conventional Chern-Simons term is nonzero only at finite temperature, whereas the higher-derivative term is finite at zero temperature, however, this term goes to zero when the temperature increases infinitely. In the second part of our study, we have shown that the higher-derivative Chern-Simons term is induced at zero temperature, nevertheless, this term goes to zero when the temperature increases too much. / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Nesta dissertação, estudamos a possibilidade de violação da invariância de Lorentz levando em conta alguns termos do modelo padrão estendido, mais especificamente, da parte deste modelo que trata da eletrodinâmica quântica estendida. Realizamos correções quânticas no setor fermiônico da eletrodinâmica quântica usual adicionada de termos que violam as simetrias de Lorentz e CPT em duas configurações diferentes. Primeiramente, adicionando operadores governados pelo coeficiente gκλμ e, em um momento posterior, adicionando operadores governados pelo coeficiente bμ. Para a teoria com o coeficiente gκλμ, realizamos correções quânticas com a intenção de induzir, no setor bosônico da teoria, os termos de Chern-Simons convencional e o de derivada superior, e analisar o comportamento de ambos os termos no regime de temperatura finita, fazendo o uso do método da expansão derivativa e do formalismo de Matsubara. Já para o modelo com o coeficiente bμ, realizamos correções quânticas a fim de induzir, no setor bosônico, o termo de Chern-Simons de derivada superior, usando o método da expansão derivativa e, posteriormente, analisar o comportamento deste termo no regime de temperatura finita, ao utilizarmos novamente o formalismo de Matsubara. Assim, para o primeiro caso, notamos que o termo de Chern-Simons convencional é diferente de zero apenas à temperatura finita, enquanto que, o termo de derivada superior é finito em temperatura zero, porém, tal termo vai a zero quando a temperatura cresce infinitamente. Na segunda parte do nosso estudo, mostramos que o termo de Chern-Simons de derivada superior é induzido no regime de temperatura zero, contudo, tal termo vai a zero quando a temperatura cresce muito.

Submitted by Salome Lema (salome.lema@hec.edu) on 2016-11-24T07:36:33Z No. of bitstreams: 1 20161102_Salome_Lema_Thesis - vf.pdf: 1739716 bytes, checksum: 9e2585c7ecc0b8105afd91779c254775 (MD5) / Approved for entry into archive by Josineide da Silva Santos Locatelli (josineide.locatelli@fgv.br) on 2016-11-24T10:16:30Z (GMT) No. of bitstreams: 1 20161102_Salome_Lema_Thesis - vf.pdf: 1739716 bytes, checksum: 9e2585c7ecc0b8105afd91779c254775 (MD5) / Made available in DSpace on 2016-11-24T11:16:37Z (GMT). No. of bitstreams: 1 20161102_Salome_Lema_Thesis - vf.pdf: 1739716 bytes, checksum: 9e2585c7ecc0b8105afd91779c254775 (MD5) Previous issue date: 2016-11-24 / In August 2011, the Brazilian government taxed short positions in the foreign exchange (FX) derivative market in order to weaken the surge of post-crisis capital inflow, discourage carry trade strategies on the Real and avoid further local currency appreciation. Nevertheless, nonfinancial firms are also end-users of derivatives and might have suffered in case financial institutions transfer the regulatory cost to their clients in the real economy. To the extent that this tax increases the cost of hedging, firms may decide to hedge less, causing an increase in their exposure to currency risk. This paper aims at analysing if this regulatory change had an impact on Brazilian non-financial firms FX exposure, measured by the sensitivity of stock prices to currency fluctuation (FX-Beta). Therefore, it seeks to compare the FX beta of Brazilian non-financial listed firms before and after the implementation of the measure, to assess their degree of exposure to currency risk. In accordance with an increasing cost of hedging for those companies, results show that the beta difference also reached a riskier level. / Em agosto de 2011, o governo brasileiro passou a tributar posições vendidas no mercado de derivativos cambiais para diminuir o influxo de capital estrangeiro no pós-crise, desencorajar operações de carry trade e evitar que o real continuasse a se valorizar frente ao dólar. No entanto, empresas não financeiras também são usuárias de derivativos, e podem ter tido seus custos de proteção cambial aumentados, caso as instituições financeiras tenham transferido esse custo adicional para seus clientes na economia real. Na medida em que o tributo aumenta o custo de fazer proteção cambial com derivativos, as empresas podem ter decidido proteger uma parcela menor de sua exposição, causando um aumento em sua exposição cambial. Essa dissertação analisa se essa mudança regulatória teve um impacto na exposição cambial das empresas não financeiras, medida pela sensibilidade do preço das ações às variações cambiais (FX-Beta). Assim, o estudo compara os FX-Betas das empresas brasileiras antes e depois da implementação do tributo, para medir o grau de mudança em suas exposições cambiais. Em linha com o aumento no custo do hedge para essas empresas, os resultados mostram alguma evidência de que algumas empresas se tornaram mais expostas ao câmbio.

Objetivos: os objetivos gerais deste trabalho foram desenvolver, validar e comparar métodos analíticos para caracterização e determinação quantitativa de vildagliptina (VLG) na forma farmacêutica comprimidos, assim como determinar a cinética de degradação do fármaco em condição de estresse. Métodos: método indicativo de estabilidade por cromatografia líquida de alta eficiência com detecção ultravioleta (CLAE-UV) foi desenvolvido e validado, conforme as normas da International Conference on Harmonisation (ICH). A cinética de degradação do fármaco foi determinada frente à hidrólise alcalina. A possível estrutura do produto de degradação majoritário, formado sob condições básicas, oxidativas e térmicas foi proposta de acordo com análises realizadas por espectrometria de massas (EM). Foi desenvolvido e validado, também, método por espectrofotometria ultravioleta derivada para quantificação do fármaco na forma farmacêutica. Resultados e Conclusões: o método de CLAE indicativo de estabilidade desenvolvido e validado demonstrou ser adequado para a quantificação da substância ativa na forma farmacêutica sem sofrer a interferência dos excipientes presentes na formulação e também na presença dos produtos de degradação. Os principais fatores extrínsecos que promoveram a degradação do fármaco foram: oxidação, hidrólise alcalina e temperatura. Determinou-se a cinética de degradação, sob condições alcalinas, como sendo de primeira ordem indicando, assim, que o processo de degradação é dependente da concentração de fármaco. O método por espectrofotometria UV derivada também se mostrou adequado para a quantificação de vildagliptina nos comprimidos. A comparação entre os métodos desenvolvidos não mostrou diferença estatística significativa demonstrando que ambos os métodos podem ser utilizados para determinação de vildagliptina no controle de qualidade dos comprimidos. / Objectives: the aim of the present work was to develop, validate and compare analytical methods to characterization and quantitative determination of vildagliptin (VLG) in tablet dosage form, as well as to determinate the degradation kinetics of the drug in a stress condition. Methods: stability-indicating method for the analysis of VLG by high performance liquid chromatography (HPLC) with ultraviolet detection was developed and validated according to the International Conference on Harmonisation (ICH) guidelines. The degradation kinetics of the drug under the alkaline hydrolysis was determined. The possible molecular structure of the major degradation product obtained under the stress studies by alkaline hydrolysis, oxidation and thermal degradation was predicted by mass spectrometry (MS) Results and Conclusions: The developed stability-indicating method was adequate to determine the active substance in the formulation even in the presence of the excipient ingredients in the formulation and, also, in the presence of the degradation products. The main extrinsic factors which promoted the drug degradation were: oxidation, alkaline hydrolysis and thermal degradation. The degradation kinetics was determined, under alkaline conditions, as first order showing that the process is dependent on the drug concentration. The derivative spectrophotometric method also was adequate to the quantification of vildagliptin in tablets. There was no statistical significant difference between the methods demonstrating that both methods can be used for the determination of vildagliptin in quality control of pharmaceutical tablets.

A associação entre os fármacos delapril (DEL) e manidipino (MAN) apresenta um efeito anti-hipertensivo sinérgico de longa duração, sendo considerada uma importante alternativa no tratamento e controle da hipertensão arterial. O presente trabalho faz referência à utilização de diversas técnicas instrumentais para avaliar a qualidade de DEL e MAN na forma farmacêutica e matérias-primas. Neste sentido, amostras de matérias-primas dos fármacos provenientes de diferentes fornecedores foram analisadas utilizando a calorimetria diferencial exploratória, termogravimetria, difração de raios X, espectrofotometria no infravermelho, espectroscopia Raman e microscopia eletrônica de varredura. Os resultados permitiram observar inconsistências entre as amostras de DEL, provavelmente devido à presença de uma impureza em uma das substâncias, demonstrando a importância da pesquisa e controle dos insumos farmacêuticos, bem como de programas de qualificação de fornecedores. Além disso, metodologias analíticas por espectrofotometria derivada, cromatografia líquida com detecção no ultravioleta (CL-UV) e CL acoplada à espectrometria de massas (EM) foram desenvolvidas objetivando a determinação de DEL e MAN nos comprimidos. Os procedimentos foram validados, cumprindo com os requisitos internacionalmente aceitos para especificidade, linearidade, precisão, exatidão, robustez e limites de detecção e quantificação, além de demonstrarem diferença não significativa (p > 0,05) entre si na quantificação simultânea dos fármacos. A estabilidade dos fármacos nas condições alcalina e fotolítica (para o DEL e MAN, respecivamente) também foi investigada. Através dos métodos por CL-UV e CL-EM pode-se propor a identidade dos principais produtos de degradação formados, os quais não apresentaram evidências de citotoxicidade em estudo utilizando células mononucleares humanas. Além disso, os estudos de cinéticas de degradação indicaram que o DEL segue uma cinética de primeira ordem (R2 = 0,9991) enquanto o MAN segue uma reação de ordem zero (R2 = 0,9867). De forma adicional, foi desenvolvido e validado um método de dissolução para avaliação de comprimidos contendo DEL e MAN. O uso de tampão citrato pH 3,2 como meio de dissolução e dispositivo pá a 75 rpm demonstrou resultados satisfatórios para a avaliação da liberação simultânea dos fármacos do produto farmacêutico, bem como capacidade de simular o comportamento in vivo do MAN a partir de dados da literatura. Desse modo, estabeleceram-se procedimentos analíticos que podem ser aplicados para aprimorar o controle da qualidade dos medicamentos a serem comercializados, bem como contribuir para garantir a segurança e eficácia no uso terapêutico. / The association of delapril (DEL) and manidipine (MAN) has a synergic antihypertensive effect and may be regarded as an important alternative to arterial hypertension treatment. The present study refers to use of some instrumental techniques to assess the quality of DEL and MAN in pharmaceutical formulation and raw materials. In this context, samples of the drugs raw materials, obtained from different suppliers, were evaluated using differential scanning calorimetry, thermogravimety, X-ray powder diffraction, infrared spectroscopy, Raman spectroscopy and scanning electron microscopy. Inconsistent results were observed between DEL samples, probably due to an impurity presence in some substance, demonstrating the importance of research and control of pharmaceutical ingredients, as well as the quality programs of pharmaceuticals suppliers. In addition, a derivative spectrophotometric, liquid chromatography (LC) and LC coupled to mass spectrometry (MS) methods were developed for simultaneous analysis of DEL and MAN in commercial tablets. The procedures were validated and the results were in accordance with internationally accepted requirements by specificity, linearity, precision, accuracy, robustness and detection and quantitation limits. Therefore, the methods were successfully applied for the simultaneous quantitative analysis of DEL and MAN in the tablet dosage form, showing non-significant difference (p > 0.05). The drugs stability in alkaline and photolytic conditions (for DEL and MAN, respectively) was also investigated. The main degradation products formed were analyzed by LC-UV and LC-ESI-MS methods and its identity could be suggested, without isolation or purification processes. Additionally, the degradation kinetic of both drugs and the cytotoxicity of the degraded samples were also studied. No evidence of cytotoxicity in human mononuclear cells was observed for drugs degraded samples. Furthermore, the present study also conducted the development and validation of a dissolution method for DEL and MAN combination tablets. The use of citrate buffer pH 3.2 as dissolution medium in combination with paddle at rotation of 75 rpm, resulted in an appropriate dissolution profile of both drugs, allowing the simultaneous quality control of DEL and MAN in combination tablets, as well as the ability to simulate the in vivo behavior of MAN from literature data. Then, the established procedures can be applied to improve the quality control of the products that will be marketed, as well as to contribute for assure the safety and therapeutic efficacy of the drugs.

Plantas do gênero Hypericum são bem conhecidas por sua utilização na medicina tradicional, sendo Hypericum perforatum a espécie mais estudada. No Sul do Brasil, esse gênero é representado por cerca de 20 espécies, entre elas, destaca-se H. polyanthemum, o qual apresenta em extrato lipofílico a presença de uliginosina B, um derivado de floroglucinol, e três benzopiranos: HP1, HP2 e HP3. Partes aéreas de H. polyanthemum foram submetidas à extração com fluido supercrítico (SFE), sendo realizadas extrações sucessivas com dióxido de carbono nas pressões de 90, 120, 150 e 200 bar, em diferentes temperaturas (40, 50 e 60 °C). Posteriormente, as frações obtidas foram comparadas com extrato n-hexano obtido por técnica convencional (ultra-som). SFE apresentou maior seletividade que a extração com nhexano, sendo a 50 °C a melhor condição para extrair os metabólitos bioativos. Para extração do composto com maior peso molecular, uliginosina B, pressões mais elevadas foram necessárias. Além disso, avaliou-se a atividade anti- Trichomonas vaginalis do extrato obtido por SFE a 50 °C/150 bar e dos compostos isolados. Os resultados indicam que todas as amostras testadas possuem atividade anti-T. vaginalis, porém, HP1 demonstrou melhor seletividade frente ao protozoário (isolado metronidazol-resistente e -suscetível), sem apresentar citotoxicidade contra células de mamíferos. Ainda, o HP1 apresentou satisfatória atividade contra isolado metronidazol-resistente (52% de trofozoítos viáveis), apresentando efeito sinérgico quando testado com baixa concentração de metronidazol (23% de trofozoítos viáveis). Todos os compostos isolados provocaram danos na membrana do parasito (liberação de LDH > 90%) e nenhuma das amostras apresentou efeito hemolítico importante, sendo que HP2 e uliginosina B apresentaram citotoxicidade frente a células de mamíferos. Portanto, benzopiranos e derivados de floroglucinol são moléculas promissoras como protótipos para novos fármacos tricomonicida, principalmente HP1, visto que corrobora com a ação do metronidazol em isolados de T. vaginalis resistentes. No entanto, mais estudos são necessários a fim de melhorar a atividade antiprotozoária das moléculas testadas, sem que as mesmas apresentem toxicidade para células de mamíferos. / Plants of the genus Hypericum are well known for their use in traditional medicine, being H. perforatum the most important species. In South Brazil, this genus is represented by approximately 20 species and among them, H. polyanthemum showed in the lipophilic extract the presence of uliginosin B, a phloroglucinol derivative, and three benzopyrans: HP1, HP2 and HP3. Aerial parts of H. polyanthemum were submitted a supercritical fluid extraction (SFE), being successively extracted with supercritical carbon dioxide under pressures of 90, 120, 150 and 200 bar at different temperatures (40, 50 and 60 ºC), and compared with the n-hexane extract obtained by ultrasound-assisted extraction. SFE presented higher selectivity than the n-hexane extration. The best condition to extract the target metabolites has been determined to be at 50 °C, being that for the high molecularweight compound, uliginosin B, higher pressures was required. Moreover, the anti- Trichomonas vaginalis activity of the extract obtained by SFE at 50 °C/150 bar and the isolated compounds was evaluated. The results showed that all samples have anti-T. vaginalis activity; however, HP1 demonstrated the best selectivity against this protozoa (metronidazole-resistant and -susceptible isolates), with no cytotoxicity against mammalian cells. In addition, HP1 has good activity against metronidazoleresistant isolate (52% of viable trophozoites), presenting synergic effect when tested with low concentration of metronidazole (23% of viable trophozoites). All isolated compounds caused damage in the parasites membrane, revealed by more than 90% of LDH release. None of the samples presented important hemolytic effect, and HP2 and uliginosin B presented cytotoxicity against mammalian cells. Therefore, benzopyrans and phloroglucinol derivative are promising molecules as prototypes for new antiprotozoal drugs, especially HP1, which improve metronidazole action against a resistant T. vaginalis isolate. Nevertheless, more studies are necessary in order to enhance their in vitro antiprotozoal activity without toxicity for mammalian cells.

It was the purpose of this design study to explore the Geometer’s Sketchpad dynamic mathematics software as a tool to model the derivative in introductory calculus in a manner that would foster a deeper conceptual understanding of the concept – developing domain specific understanding. Sketchpad’s transformation capabilities have been proved useful in the exploration of mathematical concepts by younger learners, college students and professors. The prospect of an open-ended exploration of mathematical concepts motivated the author to pursue the possibility of representing the concept of derivative in dynamic forms. Contemporary CAS studies have predominantly dwelt on static algebraic, graphical and numeric representations and the connections that students are expected to make between them. The dynamic features of Sketchpad and such like software, have not been elaborately examined in so far as they have the potential to bridge the gap between actions, processes and concepts on the one hand and between representations on the other. In this study Sketchpad model-eliciting activities were designed, piloted and revised before a final implementation phase with undergraduate non-math major science students enrolled for an introductory calculus course. Although most of these students had some pre-calculus and calculus background, their performance in the introductory course remained dismal and their grasp of the derivative slippery. The dual meaning of the derivative as the instantaneous rate of change and as the rate of change function was modeled in Sketchpad’s multiple representational capabilities. Six forms of representation were identified: static symbolic, static graphic, static numeric, dynamic graphic, dynamic numeric and occasionally dynamic symbolic. The activities enabled students to establish conceptual links between these representations. Students were able to switch systematically from one form of (foreground or background) representation to another leading to a unique qualitative understanding of the derivative as the invariant concept across the representations. Experimental students scored significantly higher in the posttest than in the pretest. However, in comparison with control group students the experimental students performed significantly better than control students in non-routine problems. A cyclical model of developing a deeper concept image of the derivative is therefore proposed in this study. / Educational Studies / D. Ed. (Education)

La modélisation de phénomènes complexes rencontrés dans les problématiques industrielles peut conduire à l'étude de codes de simulation numérique. Ces simulateurs peuvent être très coûteux en temps d'exécution (de quelques heures à plusieurs jours), mettre en jeu des paramètres incertains et même être intrinsèquement stochastiques. Fait d'importance en optimisation basée sur de tels simulateurs, les dérivées des sorties en fonction des entrées peuvent être inexistantes, inaccessibles ou trop coûteuses à approximer correctement. Ce mémoire est organisé en quatre chapitres. Le premier chapitre traite de l'état de l'art en optimisation sans dérivées et en modélisation d'incertitudes. Les trois chapitres suivants présentent trois contributions indépendantes --- bien que liées --- au champ de l'optimisation sans dérivées en présence d'incertitudes. Le deuxième chapitre est consacré à l'émulation de codes de simulation stochastiques coûteux --- stochastiques au sens où l'exécution de simulations avec les mêmes paramètres en entrée peut donner lieu à des sorties distinctes. Tel était le sujet du projet CODESTOCH mené au Centre d'été de mathématiques et de recherche avancée en calcul scientifique (CEMRACS) au cours de l'été 2013 avec deux doctorants de Électricité de France (EDF) et du Commissariat à l'énergie atomique et aux énergies alternatives (CEA). Nous avons conçu quatre méthodes de construction d'émulateurs pour des fonctions dont les valeurs sont des densités de probabilité. Ces méthodes ont été testées sur deux exemples-jouets et appliquées à des codes de simulation industriels concernés par trois phénomènes complexes: la distribution spatiale de molécules dans un système d'hydrocarbures (IFPEN), le cycle de vie de grands transformateurs électriques (EDF) et les répercussions d'un hypothétique accident dans une centrale nucléaire (CEA). Dans les deux premiers cas l'émulation est une étape préalable à la résolution d'un problème d'optimisation. Le troisième chapitre traite de l'influence de l'inexactitude des évaluations de la fonction objectif sur la recherche directe directionnelle --- un algorithme classique d'optimisation sans dérivées. Dans les problèmes réels, l'imprécision est sans doute toujours présente. Pourtant les utilisateurs appliquent généralement les algorithmes de recherche directe sans prendre cette imprécision en compte. Nous posons trois questions. Quelle précision peut-on espérer obtenir, étant donnée l'inexactitude ? À quel prix cette précision peut-elle être atteinte ? Quels critères d'arrêt permettent de garantir cette précision ? Nous répondons à ces trois questions pour l'algorithme de recherche directe directionnelle appliqué à des fonctions dont l'imprécision sur les valeurs --- stochastique ou non --- est uniformément bornée. Nous déduisons de nos résultats un algorithme adaptatif pour utiliser efficacement des oracles de niveaux de précision distincts. Les résultats théoriques et l'algorithme sont validés avec des tests numériques et deux applications réelles: la minimisation de surface en conception mécanique et le placement de puits pétroliers en ingénierie de réservoir. Le quatrième chapitre est dédié aux problèmes d'optimisation affectés par des paramètres imprécis, dont l'imprécision est modélisée grâce à la théorie des ensembles flous. Plusieurs méthodes ont déjà été publiées pour résoudre les programmes linéaires où apparaissent des coefficients flous, mais très peu pour traiter les problèmes non linéaires. Nous proposons un algorithme pour répondre à une large classe de problèmes par tri non-dominé itératif. / The modeling of complex phenomena encountered in industrial issues can lead to the study of numerical simulation codes. These simulators may require extensive execution time (from hours to days), involve uncertain parameters and even be intrinsically stochastic. Importantly within the context of simulation-based optimization, the derivatives of the outputs with respect to the inputs may be inexistent, inaccessible or too costly to approximate reasonably. This thesis is organized in four chapters. The first chapter discusses the state of the art in derivative-free optimization and uncertainty modeling. The next three chapters introduce three independent---although connected---contributions to the field of derivative-free optimization in the presence of uncertainty. The second chapter addresses the emulation of costly stochastic simulation codes---stochastic in the sense simulations run with the same input parameters may lead to distinct outputs. Such was the matter of the CODESTOCH project carried out at the Summer mathematical research center on scientific computing and its applications (CEMRACS) during the summer of 2013, together with two Ph.D. students from Electricity of France (EDF) and the Atomic Energy and Alternative Energies Commission (CEA). We designed four methods to build emulators for functions whose values are probability density functions. These methods were tested on two toy functions and applied to industrial simulation codes concerned with three complex phenomena: the spatial distribution of molecules in a hydrocarbon system (IFPEN), the life cycle of large electric transformers (EDF) and the repercussions of a hypothetical accidental in a nuclear plant (CEA). Emulation was a preliminary process towards optimization in the first two cases. In the third chapter we consider the influence of inaccurate objective function evaluations on direct search---a classical derivative-free optimization method. In real settings inaccuracy may never vanish, however users usually apply direct search algorithms disregarding inaccuracy. We raise three questions. What precision can we hope to achieve, given the inaccuracy? How fast can this precision be attained? What stopping criteria can guarantee this precision? We answer these three questions for directional direct search applied to objective functions whose evaluation inaccuracy stochastic or not is uniformly bounded. We also derive from our results an adaptive algorithm for dealing efficiently with several oracles having different levels of accuracy. The theory and algorithm are validated with numerical tests and two industrial applications: surface minimization in mechanical design and oil well placement in reservoir engineering. The fourth chapter considers optimization problems with imprecise parameters, whose imprecision is modeled with fuzzy sets theory. A number of methods have been published to solve linear programs involving fuzzy parameters, but only a few as for nonlinear programs. We propose an algorithm to address a large class of fuzzy optimization problems by iterative non-dominated sorting. The distributions of the fuzzy parameters are assumed only partially known. We also provide a criterion to assess the precision of the solutions and make comparisons with other methods found in the literature. We show that our algorithm guarantees solutions whose level of precision at least equals the precision on the available data.

Made available in DSpace on 2014-06-11T19:26:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-07-29Bitstream added on 2014-06-13T20:14:37Z : No. of bitstreams: 1 pereira_llv_me_sjrp.pdf: 1182871 bytes, checksum: 6053df49fe569dc60c6513fafdffaa9d (MD5) / No presente trabalho verificamos que os testículos possuem morfologias diferentes podendo ser arredondados, arredondados/espiralados ou alongados/espiralados. Com relação à morfometria das células em prófase I, B. micantulum e R. zela foram as que apresentaram as menores células, G. f. flavus foi a que apresentou maior tamanho e R. c. crassifemur e M. brasiliensis apresentaram tamanho intermediário. A avaliação da espermatogênese nos permitiu concluir que as características observadas são semelhantes às das outras espécies de Heteroptera, descritas na literatura, diferindo apenas com relação à morfologia dos testículos, o número de cromossomos e o sistema cromossômico do sexo. A análise das ultraestruturas observadas durante a espermatogênese de Gelastocoris flavus flavus e Martarega uruguayensis mostraram a presença de várias mitocôndrias pequenas e uniformemente distribuidas pelo citoplasma em células em profase I, de ambas espécies, que foram se unindo formando o complexo mitocondrial, que possui no seu interior as mitocôndrias enoveladas, posteriormente este complexo mitocondrial se divide em duas estruturas denominadas derivados mitocondriais, que se dispõem bilateralmente ao axonema. O axonema dessas espécies possui o padrão de 9+9+2. A formação do acrossomo inicia-se nos primeiros estágios da espermiogênese sendo composto de muitas vesículas acrossomais que se unem formando uma única estrutura, sendo observada regiões e algumas estruturas mais coradas em seu interior. Basicamente o processo de espermiogênese não diferiu entre as duas espécies analisadas / In this study, we found different morphologies for testes of the Heteroptera species Belostoma anurum, B. micantulum, Gelastocoris angulatus, G. flavus flavus, Rheumatobates crassifemur crassifemur, Buenoa amnigenus, B. unguis, Martarega brasiliensis, M. membranacea, M. uruguayensis, Rhagovelia tenuipes and R. zela. They can by round, round/spiral and elongated/spiral. The size of prophase I cells also varied, being the smallest ones detected in B. micantulum and R. zela, the largest in G. f. flavus, and the intermediate in R. c. crassifemur and M. brasiliensis. The analyses of spermatogenesis allowed us to conclude that, in the studied species, the features are similar to those of other previously described Heteroptera species, differing only as to the testicular morphology, the chromosome number, and the sex chromosome system. Ultrastructural analysis of the spermatogenesis showed several small mitochondrias evenly distributed throughout the cytoplasm, in cells at prophase I of G. f. flavus and M. uruguayensis. The small mitochondrias joined to form the mitochondrial complex. Later, this mitochondrial complex divided into two structures called mitochondrial derivatives, located bilaterally to the axoneme. The axoneme of these species showed the flagellar pattern 9+9+2. The acrosome started to be formed in the early stages of spermiogenesis, being composed of many acrosome vesicles that join to form a single structure. Some regions within this structure were more strongly stained. Basically the process of spermiogenesis did not differ between the species G. f. flavus and M. uruguayensis

Morphological architecturing is one of the smart and efficient ways to maximize the number of excitons harvested from the known photoactive materials and existing fabrication technologies. Surfaces and interfaces play a vital role in absorbing light and therefore when patterned regularly, aid in the improvement of light absorption. This thesis deals with the study of light management by morphologically architecturing the organic electroactive materials. Here, morphological architecturing is carried out using electrospinning technique by optimizing various parameters. In the first part, organic photovoltaic system is tailored by morphologically modifying the conjugated polymer active layer and analyzing the enhancement in light collection and hence performance of photovoltaic devices. In the second part, the prospects of using free standing buffer layer instead of thin film buffer layer in a solar cell is evaluated. Furthermore, the study on morphological engineering of conjugated small molecule is carried out, by varying the solvents and derivatives, in order to control morphologies by understanding the underlying mechanism. Overall this thesis attempts to understand the fundamentals in morphological architecturing, by physical architecturing of the small molecules in a device for light management applications as well as demonstrating improvement in light absorption in existing organic photovoltaic systems. In the introduction chapter, a brief description of organic photovoltaics is given followed by highlighting the importance of processing methods in light management and in organic photovoltaics. The significance of structured architecture in improving the device characteristics is presented. The issues and challenges in existing architecturing techniques available in literature are discussed. Electrospinning as a tool for morphological modification for organic photovoltaics is demonstrated. This is followed by an outline of the thesis. In Chapter 2, brief description of procedures carried out for fabrication, characterization and optimization of electrospinning process parameters are discussed. The description of fabrication procedures including electrospinning, spincoating and thermal evaporation are given. Characterization techniques used in this thesis for surface and feature analysis, structural, compositional, optical and opto-electrical analyses are described. Optimization of electrospinning process parameters in obtaining various morphologies are evaluated. In Chapter 3, enhancement of device characteristics of poly (3-hexylthiophene): phenyl C61-butyric acid methyl ester (P3HT: PCBM) by changing active layer film morphology into network structure is elucidated. Network structure is provided by electrospraying assisted hierarchical assembly of short fibrils. Effect of electrospraying parameters such as solvent, polymer blend concentration, applied voltage, tip to collector distance, flow rate and deposition time are analyzed. Solvent and applied voltage are observed to be the major parameters governing the formation of network structure. The optimized conditions are used to investigate the optical and structural properties. Percent reflectance studies showed improvement in light absorption due to increase in surface area. Structural characterization studies indicate an increase in orientation of crystallites and crystallinity as compared to spincoated samples. The optimized conditions along with additional spincoated layer of P3HT:PCBM are used to fabricate bulk heterojunction device. Device characteristics exhibited an increase in short circuit current and thus increase in efficiency from 2.18% to 3.66%. There is a enhancement of 37.5% going from maximum external quantum efficiency of 40%-55% for electrosprayed and spincoated devices. It is anticipated that network morphology could be the next possible structure to be explored in organic photovoltaic materials. In Chapter 4, photonic structure is analyzed and compared. A photonics device requires uniform periodic structural arrangement. Various techniques are used to fabricate these types of structures, employing several steps of fabrication. This work proposes single step hierarchical array of equal submicron size porous structure fabricated by tuning electrospinning processing parameters. The dictating process parameters on evolving structure are high voltage, tip to collector distance and solvent. Morphological and optical investigations suggest that uniform periodic topography helps in light scattering leading to multi reflection and thus enhancement in light absorption. This structure is evaluated as active layer in organic photovoltaic devices using poly (3 hexyl thiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) blend and its device characteristics are analyzed. Consistent and reliable device characteristics obtained through photonic structure is demonstrated. Finally, comparison is drawn to network structure to assess the advantages and limitations of both morphologies as active layer in organic photovoltaics. In Chapter 5, instead of architecturing active layer the next polymer film layer in the organic solar cells, that is the hole transport layer is transformed into free standing nanofiber mats. Morphological, structural and surface wetting properties are assessed for these nanofiber mats followed by fabrication of inverted organic solar cell. The free standing nanofibers mats are obtained by electrospinning the blend of Poly(3,4-ethylenedioxythiophene) Polystyrene sulfonate (PEDOT:PSS) a conducting water soluble polymer with other water soluble polymers such as poly vinyl alcohol (PVA) and poly ethylene oxide (PEO). The study is further extended by employing two batches of PEDOT:PSS of varying conductivity that are analyzed side by side for six ternary and two binary blends each. Electrospinning parameters such as applied voltage and flow rate are optimized and fibers of diameter 150-200 nm are obtained. Maximum content of PEDOT:PSS with which free standing fiber mats could be achieved are 98 and 99%. Subsequent increase in PEDOT:PSS results in formation of beads. Surface wetting behavior showed that hydrophillicity increases with increase in PEDOT:PSS content. Devices are fabricated and the variation in characteristics and charge collection with respect to addition of PEO and PVA are discussed. In Chapter 6, a conjugated small molecule is taken as case study unlike the use of the conjugated polymer studies in previous chapters. A mechanism is proposed for tuning the sphere-spike morphology and also to control the crystallite size through solvent management using a conjugated small molecule. Electrospraying of an organic molecule is carried out using various solvents, obtaining fibril structures along with a range of distinct morphologies. Solvent characteristics play a major role in achieving the morphology of the organic material. A thiophene derivative (7, 9-di (thiophen-2-yl)-8H-cyclopenta [a]acenaphthylen-8-one) (DTCPA) of donor-acceptor-donor (DAD) architecture is used to study this solvent effect. Seven solvents with decreasing vapor pressure are selected for experiments. Electrospraying is conducted at a solution concentration of 1.5 wt % and a constant applied voltage of 15 kV. Gradual transformation in morphology of the electrospun product from spikes-sphere to only spikes is observed. A mechanism describing this transformation is proposed based on the electron micrograph analysis and XRD analysis. These data indicate that the morphological change is due to the synergistic effect of both vapor pressure and dielectric constant of the solvents. Through a reasonable control over the crystallites size and morphology along with supporting transformation mechanism theory, the work in this chapter elucidates electrospraying as a prospective method for designing the architectures in organic electronics. In Chapter 7, light management studies are carried out by morphologically architecturing the carbazole derivatives through electrospraying. The effect of derivatives on morphology is analyzed. The two carbazole derivatives; carbazole-benzothiadiazole (Cz-Bz) resulted in 2D structures and carbazole-benzothiadiazole-bithiophene (Cz-Bz-Bt) resulted in 3D structures after electrospraying. These structures are further analyzed to study the effect of vapor pressure of solvents and solution concentration. Structural characteristics indicate that electrospraying imparts change in molecular structure orientation. Optical studies showed 19 – 31% enhancement in light absorption. Further, three types of organic photovoltaic devices are fabricated and the opto-electrical properties are evaluated. Also, the effect of substrate on morphological formation is assessed. In Chapter 8, the major contributions and conclusions drawn from the morphological architecturing of both conjugated polymers and small molecules are summarized, along with few recommendations for future research.

O ritonavir (RTV) é um anti-retroviral, inibidor da protease do VIH, produzido nas formas farmacêuticas cápsula e solução oral sob o nome comercial Norvir® (Abbott). Levando-se em consideração que o RTV está sendo sintetizado no Brasil e que não existem métodos oficiais para o seu doseamento na forma farmacêutica cápsula, faz-se necessário o desenvolvimento e validação de métodos para assegurar a qualidade do produto acabado. Deste modo, o objetivo deste trabalho foi a validação de métodos analíticos para o controle qualitativo e quantitativo do RTV matéria-prima e cápsulas, assim como a realização de estudo preliminar para avaliar a estabilidade da matéria-prima. A identificação e caracterização do fármaco e seus polimorfos (forma I e II) foi realizada através da análise do ponto de fusão, calorimetria exploratória diferencial (DSC), rotação específica, métodos espectrofotométricos na região do infravermelho (IV) e do ultravioleta (UV), cromatografia em camada delgada (CCD) e cromatografia líquida de alta eficiência (CLAE), microscopia óptica (MO) e eletrônica de varredura (MEV), além da difração de raios-X. Para a determinação quantitativa foram validados, segundo normas da International Conference on Harmonization (ICH), os métodos de espectrofotometria na região do UV, ordem-zero e segunda derivada (UV-D2), e CLAE. A análise estatística demonstrou equivalência entre os métodos CLAE / UV para a determinação do teor da matéria-prima e entre os métodos CLAE / UV-D2 para a determinação do RTV nas cápsulas. No estudo preliminar de estabilidade térmica e fotoestabilidade, a matéria-prima foi submetida à temperatura de 60 °C por 30 dias e permaneceu sob luz branca por até 15 dias respectivamente. A CLAE foi o método empregado na análise do teor e pureza das amostras submetidas às degradações, sendo que os resultados demonstraram a estabilidade da matéria-prima nas condições testadas, não havendo redução significativa do teor do fármaco nem aparecimento de potenciais produtos de degradação. / Ritonavir (RTV) is a HIV-protease inhibitor, available as capsule and oral solution (Norvir®). Considering that the drug has been produced in Brazil and there are no official methods to quantify RTV capsules, it became necessary the development and validation of methods for ensuring the quality of pharmaceutical formulations. The objective of this work was the validation of these analytical methods for the qualitative and quantitative analysis of RTV bulk substance and capsules. A preliminary studie of stability was also performed. RTV identification and polymorphs I and II characterization were performed by using several techniques such as: melting point, differential scanning calorimetry (DSC), optical rotation, infrared (IR) and ultraviolet (UV) spectrophotometry, thin-layer chromatography, high performance liquid chromatography (HPLC), optical and scanning electron microscopy, and powder X-ray diffraction. The HPLC, zero-order UV spectrophotometric and second-derivative UV spectrophotometric (UV-D2) methods were validated according to the International Conference on Harmonization (ICH) guidelines for the quantitative determination of RTV bulk substance and capsules. The statistics analysis showed that HPLC / UV methods were equivalent to assay bulk substance and HPLC / UV-D2 methods were equivalent to assay capsules. The preliminary studies of thermal and photostability were conducted by exposing RTV samples at 60 °C during 30 days and under fluorescent lamp during 15 days. The developed HPLC method was used to assay the drug and detect its potential degradation products. The results showed that the RTV bulk substance was stable and there was no evidence of its degradation, under the established conditions.