Made available in DSpace on 2015-04-20T12:31:49Z (GMT). No. of bitstreams: 1 Carlos Gustavo Nunes da Silva.pdf: 7132119 bytes, checksum: 87b96758db3807b14b707d1380997db6 (MD5) Previous issue date: 2008-03-24 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The presence of castes among females and a sytem of seasonal production of males in order to fund new daughter colonies or replace the Queen, is essencial to life in society for the high eusocial bees. The haplodiploidy has unique consequences to the populational ecology and social oveolutinos for the social bees. Studies have shown, in depleted popultions, that consecutive mating between indviduals with equal allele composition for the sex determination gene can cause its extinction. The sex determination genes csd (complementary sex determiner) and fem (feminizer) seems to be at the top of a regulatory cascade in which will originate the different phenotypes, which is indeed a essential way to mainten the eusociability in bees. The sex determination system as well as the several distincts caste determination systems existing among the high eusocial bess are yet poorly undertood in their genetic basis and seems to be fairly complex as diverse. The goal of this thesis was to sequence genes envolved in the sex or caste determination in the Melipona bees. Using the RACE (Rapid Amplification of cDNA Ends) technique, the gene fem (feminizer) was cloned and sequenced in M. compressipes and analysed with help of bioinformatcis tools. The analysis show in Melipona compressipes that the predict gene product have 64% of identity and 75% of similarity with its equivalent (Fem) in Apis mellifera, posesing the same protein domains: Arginime-Serine domain (RS-domain) and proline domain (proline rich dormain). The gene fem in M. compressipes as in Apis, do not have hyper variable region which characterizes its paralog gene csd Thus, as this work proposes would indicate that the fem product would have function in the activation of genes in Melipona switching on other secondary feminizer genes in contrast with the masculining genes, which are constitutive.We propose a model that that put together literature information with the new gene fem findings in Melipona, aiming a discussion about the relulatory cascade which surpass from the sex determination / A presença de castas entre as fêmeas e um sistema de produção sazonal de machos para renovação da rainha ou fundação de colônias filhas é fundamental para a vida em sociedade nas abelhas eusociais. Um sistema peculiar de determinação sexual é encontrado nesses insetos considerados organismos haplodiplóides, no quais, machos viáveis reprodutivamete são haplóides nascidos por partenogêne arrenótica (ovos não fecundados dando origem a machos), enquanto fêmeas são originadas de ovos fecundados. A haplodiploidia tem conseqüências fundamentais para a ecologia populacional e evolução social. A determinação das castas, por sua vez, em abelhas do gênero Melipona é sustentada pela hipótese do sistema genético-alimentar proposta por (KERR,1974), sendo dependente da dupla heterozigose, dos genes xa e xb (cada um com dois alelos). O objetivo desse trabalho foi o de seqüenciar genes envolvidos na determinação de sexo e ou castas em abelhas do gênero Melipona. Por meio de técnicas de isolamento gênico, utilizando o método de amplificação de extremidades para a obtenção de cDNAs completos (Rapid Amplification of Cdna Ends RACE). O gene fem (feminizer) foi clonado e seqüenciado em M. compressipes e analizado com o auxílio de ferramentas de bioinformática. Os resultados da análise mostram, que em Melipona compressipes, o produto predito do gene tem 64% de identidade e 75% de similaridade com o equivalente (fem) em Apis mellifera. Possuindo os mesmos domínios ricos em prolina (proline rich domain). Além disso, o gene fem é expresso em todos os instares imaturos e inclusive em adultos e igualmente encontrado em cDNAs de machos, operárias e rainhas, mostrando, da mesma forma que em A. mellifera, que esse é um gene expresso em todas as fases do desenvolvimento e em ambos sexos e castas, além de ser muito conservado interespecificamente. O gene fem, não possui a região hipervariada. Isso, segundo proposta desse trabalho, indicaria outros genes além de fem teria funções na ativação dos genes de castas em Melipona e dispararia outros genes feminizantes em contraposição aos genes masculinizantes, esses, por sua vez, constitutivos. É proposto um modelo, que reúne as informações da literatura com a descoberta do gene fem em Melipona

Las cintas superconductoras de alta temperatura (HTS) han emergido como materiales prometedores para sus uso en el campo de l'energía puesto que permiten reducir a mitad el tamaño de los equipos de energía eléctrica respecto a los convencionales, reducir las pérdidas de energía, aumentar la eficacia en la generación, la transmisión y la distribución de la misma, y así la reducir el impacto ambiental.Sin embargo, diversamente de los conductores típicos, los materiales superconductores basados en óxido son frágiles, se dañado fácilmente y son así difíciles de procesar. Hasta ahora ha sido posible producir longitudes de un kilómetro de cables HTS de primera generación, para el uso en el trasporte de corriente eléctrica. Las cintas superconductoras de YBCO, por ejemplo, pueden soportar altas densidades de corrientes críticas y por esto representan un candidato prometedor en el trasporte de electricidad.Uno del los substratos disponible para suportar el superconductor es un acero policristalino con una película epitaxial de YSZ en cima, YSZ(IBAD)/Stainless. El segundo que hemos utilizado es el NiO(SOE)/Ni(Rabit), una cinta de nickel previamente texturada por laminación y sucesivamente oxidata de manera controlada. Numerosas técnicas están disponible para la deposición de YBCO epitaxiale, nosotros elegimos el proceso más barato y industrialmente interesante: la técnica sol-gel. Para evitar la interacción entre el YBCO superconductor y el substrato epitaxial, evitando así la reducción de la corriente que el superconductor puede trasportar, es importante interponer un material inerte que transfiera su epitaxia al YBCO; este clase de películas se llaman capas tampón. El objetivo principal de esta tesis ha sido optimizar el crecimiento de las capas tampón por técnica química y finalmente estudiar la deposición del YBCO por TFA sobres esas muestras optimizadas. Las capas de cerámica que hemos estudiados han sido: CeO2, BaZrO3, CaZrO3, SrZrO3, SrTiO3, BaCeO3 , y depositadas por el método químico: metal 2-4-&#61538;-diketone disuelto en ácido acético, o los metales isopropoxidos disuelto en metanol. Por depositar las soluciones precursoras hemos utilizado la técnica de spin coating. Controlando los diversos parámetros, velocidad, aceleración y la concentración de la solución obtuvimos películas homogéneas con diverso grosor. La fase de la cristalización se alcanza en un horno donde se controla l'atmósfera, la temperatura y la velocidad de calefacción. Durante esta investigación hemos adquirido un conocimiento total del acrecimiento de las películas delgada de MOD-CeO2. De una combinación de las análisis de TEM, de XRD y de RHEED observamos que el mecanismo de crecimiento tiene un comportamiento anómalo comparado con el otro materiales crecidos con la misma técnica.En este proceso de síntesis de la ceria, la nucleation homogénea de hecho esta favorita debido al bajo valor de Tnuc./Tmel ceria (Tnuc./Tmel=0.21). Solamente los granos nucleados sobre el substrato resultan texturados. La dependencia del tamaño de grano con temperatura sigue una relación de tipo Arrhenius, características de un crecimiento 3D del grano. Los análisis de EELS revelaron una fracción significativa de C residual que adorna los límites de grano, es probable que el crecimiento del límite de grano se quede bloqueando debido estas impurezas.Un proceso del recocido en aire a posteriores, ha demostrado la posibilidad de crecer las películas de CeO2 totalmente epitaxiales. Los análisis de EELS de tales muestras tratadas en oxígeno demuestran claramente que los límites de grano quedan limpios de las impurezas de C, desbloqueando así el crecimiento del grano. Después de un proceso largo de optimización de los parámetros de síntesis, podemos ahora controlar exactamente el crecimiento epitaxiale de la ceria. Se ha verificado que el óxido del cerio se puede crecer en YSZ(IBAD)/SS con solamente la orientación (00l). Para preservar la cinta del metal contra la oxidación, el proceso optimizado se ha adaptado a la deposición sobre substrato de acero inoxidable reduciendo la temperatura de síntesis a 900ºC. Hemos optimizado también la preparación de SrTiO3(STO) y BaZrO3(BZO) sobre MgO y YSZ mono-cristales y en seguida también sobre YSZ(IBAD)/SS y NiO(SOE)/Ni.La arquitectura más prometedora resultó ser STO/BZO/NiO(SOE)/Ni. Por ultimo depositamos YBCO por método TFA (Trifluoracéticetatos) sobre las capas tampones optimizadas. Una muestra de TFA-YBCO sobre CeO2/YSZ(IBAD)/SS preparada en aire a 900ºC en 8 h ha dato como resultado una densidad corriente crítica, Jc de 7 MA/cm2 a 5K, y 6·105A/cm2 a 77K. Estos valores están cerca de objectivo de un millón A/cm2 a 77K. Los experimentos sobre las capas tampón de BZO y de STO han demostrado la posibilidad de usar este sistema doble sobre NiO(SOE)/Ni como plantilla alternativa para el crecimiento de YBCO. Alcanzado una densidad de corriente crítica de Jc(5K) = 5·105A/cm2 con la mejor muestra de YBCO/STO/BZO/NiO(SOE)/Ni. / High-temperature superconducting (HTS) tapes have emerged as promising materials for superconducting power applications since they make possible electric power equipment that is half the size of conventional alternatives, with half energy losses, increasing the efficiency in the generation, transmission and distribution of the electric energy, and thus reducing the impact of power delivery on the environment. However, unlike typical conductors, oxide based superconductor materials are brittle and easily damaged and thus they are difficult to process and handle, specially forming large and flexible wires.Up to now it has been possible to produce kilometre lengths of the first generation of HTS wires for use in electrical transmission cables. YBCO coated conductors can support high critical current densities and is a promising candidate. One of the substrate available is a polycrystalline metal substrate with an epitaxial YSZ film on it, the ion-beam assisted deposition YSZ(IBAD)/Stainless Steel. The second is the textured NiO(SOE)/Ni(Rabit).Numerous methods are available for epitaxial deposition of YBCO, including vacuum techniques but we choose the cheaper non vacuum sol-gel processes.To avoid the interaction between the superconductor it is important to interpose a inert material that can transfer the epitaxy from the substrate to the YBCO, these kind of films are called buffer layers, avoiding than the reduction of the current that the superconductor can support. The main aim of this thesis was optimising the buffer layer growth by chemical technique and finally studying the deposition of TFA-YBCO on those optimised templates.The ceramic buffer layers studied:CeO2 , BaZrO3 , CaZrO3, SrZrO3, SrTiO3,BaCeO3The Sol-Gel system used was the Metal &#61538;-diketone dissolved in Acid Acetic, or Metal isopropoxide dissolved in methanol.The deposition step was performed by spin coating. Controlling the different parameters of rate and acceleration of the spinner and the precursor solution concentration we obtained homogenous films with different thickness. The crystallisation step is achieved in a furnace in a controlled atmosphere, temperature and heating rate.Important knowledge on the MOD-CeO2 thin film growth has been acquired during this research. From a combination of TEM, XRD and RHEED analyses it was observed that its growth mechanism exhibits an anomalous behaviour compared with other CSD derived films. The homogeneous nucleation in fact is favoured in this MOD process due to the low Tnuc./Tmel value for ceria film (Tnuc./Tmel=0.21). Only grains nucleated on the substrate are textured as observed in XTEM images. The grain size dependence with temperature follows an Arrhenius relation: <r>2=&#61537;otexp(-Q/kT), characteristics of 3D undergoing thermally activated grain growth . EELS analyses revealed a significant fraction of residual C decorating the grain boundaries, that very likely acts as a growth by blocking grain boundary motion. A process of post annealing or direct growth in static air, have demonstrated the possibility of growing completely epitaxial CeO2 films. EELS analyses of such samples clearly demonstrates that the oxygen clean up grain boundaries from C impurities thus unblocking grain growth. After a long process of synthesis parameter optimisation, we are now able to control exactly the epitaxial growth of ceria growth. It has been verified that Cerium oxide can be grown on YSZ(IBAD)/SS with only the (00l) orientation. The optimised process has been adapted to stainless steel substrate reducing the synthesis temperature at 900ºC in order to preserve the metal tape against oxidation. We observed an interesting phenomenon of in plane texture improvement of the ceria film with respect to the underlying YSZ(IBAD)/SS substrate, from &#61508;&#61542;YSZ = 8.3º and to &#61508;&#61542;CeO2 = 7.5º.The solution preparation and the deposition conditions for STO and BZO on MgO and YSZ have been also optimised. After several experiments of buffer deposition on YSZ(IBAD)/SS and NiO(SOE)/Ni technical metal substrates the most promising architecture resulted to be the STO/BZO/NiO(SOE)/Ni. We have grown YBCO by the TFA(Trifluor Acetic Acid) method on the optimized buffer layers. A sample of TFA-YBCO on a CeO2/YSZ(IBAD)/SS template prepared in air at 900ºC for 8 h has shown a critical current density, Jc has a value of 7 MA/cm2 at 5K, and 6·105A/cm2 at 77K. These values are near the target of one million A/cm2 at 77K. The experiments on BZO and STO buffer layers have demonstrated the possibility of using the double buffer on NiO(SOE)/Ni as an alternative template for YBCO deposition. A critical current density of Jc(5K)= 5·105A/cm2 has been achieved for the best sample of YBCO/STO/BZO/NiO(SOE)/Ni.

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With advanced subsonic transports and military aircraft operating in the transonic regime, it is becoming important to determine the effects of the coupling between aerodynamic loads and elastic forces. Since aeroelastic effects can contribute significantly to the design of these aircraft, there is a strong need in the aerospace industry to predict these aero-structure interactions computationally. To perform static aeroelastic analysis in the transonic regime, high fidelity computational fluid dynamics (CFD) analysis tools must be used in conjunction with high fidelity computational structural dynamics (CSD)analysis tools due to the nonlinear behavior of the aerodynamics in the transonic regime. There is also a need to be able to use a wide variety of CFD and CSD tools to predict these aeroelastic effects in the transonic regime. Because source codes are not always available, it is necessary to couple the CFD and CSD codes without alteration of the source codes. In this study, an aeroelastic coupling procedure is developed which will perform static aeroelastic analysis using any CFD and CSD code with little code integration. The aeroelastic coupling procedure is demonstrated on an F/A-18 Stabilator using NASTD (an in-house McDonnell Douglas CFD code)and NASTRAN. In addition, the Aeroelastic Research Wing (ARW-2) is used for demonstration of the aeroelastic coupling procedure by using ENSAERO (NASA Ames Research Center CFD code) and a finite element wing-box code (developed as a part of this research). The results obtained from the present study are compared with those available from an experimental study conducted at NASA Langley Research Center and a study conducted at NASA Ames Research Center using ENSAERO and modal superposition. The results compare well with experimental data. In addition, parallel computing power is used to investigate parallel static aeroelastic analysis because obtaining an aeroelastic solution using CFD/CSD methods is computationally intensive. A parallel finite element wing-box code is developed and coupled with an existing parallel Euler code to perform static aeroelastic analysis. A typical wing-body configuration is used to investigate the applicability of parallel computing to this analysis. Performance of the parallel aeroelastic analysis is shown to be poor; however with advances being made in the arena of parallel computing, there is definitely a need to continue research in this area. / Ph. D.

To understand the complex structure of magmatic plumbing systems beneath volcanoes, one needs to study the different textures shown in the igneous rocks produced by the volcano in question. By doing this, one can get a clue of the processes that resulted in the final rock. One of the most important methods to use for studying rock samples is the Crystal Size Distribution (CSD), which can reveal a great amount of information about the history of the rock and give an insight in the journey of the crystals during their time in the magma. An extinct volcano named Chachahuén, located in Argentina, South America, was chosen for this study. Samples of rock were collected from one of its laccoliths named Cerro Bayo and was identified as hornblende-bearing dacite. The difference in crystal size was very significant in these samples, with both larger and smaller crystals embedded in the same matrix. This is interesting considering the fact that large crystals form by slow cooling of the magma while smaller crystals form as the magma cools rapidly. By studying the CSD and interpreting other textures found in samples of igneous rock, one may interpret different processes which affected the crystals, indicating what the structure of the magma chamber once looked like. / För att kunna förstå den komplexa strukturen hos magmatiska system under vulkaner måste man studera olika texturer som påträffas i de magmatiska bergarter producerade av vulkanen i fråga. Genom att göra detta kan man få en inblick i de processer som resulterade i den slutgiltiga bergarten. En av de viktigaste metoderna att använda sig av för att studera stenprov är kristallstorleksfördelningen (CSD), som kan avslöja en mängd viktig information om bergarten och kristallernas historia under sin färd i magman. En slocknad vulkan vid namn Chachahuén belägen i Argentina, Sydamerika, valdes ut för denna studie. Stenprover samlades från en av dess lakkoliter med namnet Cerro Bayo, och identifierades som hornblände-bärande dacit. Skillnaden i kristallstorleken var mycket markant, med både större och mindre kristaller inbäddade i samma matrix. Detta är intressant med tanke på att stora kristaller bildas under en långsam nedkylning av magma medan mindre kristaller bildas när magma kyls ner snabbt. Genom att studera CSD och tolka andra texturer som finns hos magmatiska stenprover kan man tolka olika processer som har påverkat kristallerna, vilket i sin tur indikerar hur strukturen av magmakammaren en gång såg ut.

Sustainability is about ensuring that current and future generations have equal access to resources and a quality of life that provides long-term economic security at the same time as safeguarding the natural and cultural environment. Using a process of sustainable development (SD) it is possible to formulate management tools and planning strategies to change and direct industrial or human activities that are contrary to sustainability. SD requires unified responses to guide this process through a new set of customs and practice, and achieve acceptance and changes in the behavior and actions of individuals and organisations. The outcomes of SD will be determined by the human response to sustainability, which is in part a cultural response. Culture has a duality of meaning in every day use. It is either the value system that shapes the aspirations, identity and attitudes of individuals and groups; or the ‘way of life’ for a particular group of people who are drawn together through customs, religion, language, arts, science or technology. Culture has principles in common with sustainability by bestowing upon current generations cultural heritage and identity, as well as responsibility for safeguarding future cultural diversity and ecological balance. This thesis suggests that cultural values are a key to sustainability and that deliberate strategies and criteria are needed for the arts and creative industries to assist SD. The idea that culture is central to SD is based on the fact that sustainability is a concept whereas culture is a human value system and a way of life. Using the concept of ‘cultural capital’, this thesis identifies a framework that can guide and report both the tangible economic and physical outcomes and the intangible benefits that occur through artistic and cultural activity. Tangible outcomes include artists, buildings and creative products while intangible benefits lead to cultural identity, diversity and a sense of place. It is then suggested that if a framework based on cultural capital were applied to SD, such a process would be called ‘culturally’ sustainable development. The idea of culturally sustainable development (CSD) is explored in academic and business literature, and in the practical examples of existing action found in the Western Australian arts and cultural community. Based on this intelligence, strategies are identified to provide the next steps for developing the concept and practice of CSD. Strategies call for government, business and the arts to have equal responsibility for mainstreaming the concepts of CSD and cultural capital, and encourage CSD activities and projects. At the implementation level, strategies focus on developing a universal framework for CSD, incorporating Creative Action Plans or creative business plans, along with a CSD Index, and a creative cluster approach to project management or industry development. CSD is about investing creatively in sustainability through cultural capital, the new growth stock of SD.

No / This paper presents a novel and hardware-efficient architecture for power-of-two FFT processors. The proposed design is based on the phase-amplitude splitting technique which converts a DFT to cyclic convolutions and additions. The cyclic convolutions are implemented with a filter-like structure and the additions are computed with several stages of butterfly processing units. The proposed architecture requires no multiplier, and comparisons with other designs show it can save up to 39% total equivalent gates for an 8-bit 16-point FPGA-based FFT processor.

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Made available in DSpace on 2015-05-14T13:21:10Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 3029622 bytes, checksum: 0bf749150147c0f69a86aa470304e203 (MD5) Previous issue date: 2011-05-06 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / SrSnO3 and CaSnO3 present orthorhombic perovskite structure, due the distortions and inclination among octahedra. The distortions favor the obtainment of materials with dielectric and semiconductive properties, leading to many applications in the technological area. In this work SrSnO3 powders were obtained by the polymeric precursor method and thin films based on Ca1-xSrxSnO3were obtained by the PLD (pulsed laser deposition) and CSD (chemical solution deposition) methods. Epitaxial films with high crystalline quality were obtained on SrTiO3 (100) substrates while textured and polycrystalline films were obtained on sapphire and silica. The PLD physical method led to films with higher epitaxy degree comparing to CSD, but with a higher short range disorder. An important point was the possibility of variation of short and long range order of powders and thin films as well as of film morphology, from variation of synthesis conditions as temperature, substrate and composition. / SrSnO3 e CaSnO3 apresentam estrutura perovskita ortorrômbica, proveniente das distorção e inclinações de seus octaedros. Estas distorções favorecem a obtenção de materiais com propriedades dielétricas e semicondutoras, levando a inúmeras aplicações no setor tecnológico. Neste trabalho, pós de SrSnO3 foram obtidos pelo método dos precursores poliméricos e filmes finos no sistema Ca1-xSrxSnO3 pelos métodos PLD (do inglês, pulsed laser deposition) e CSD (do inglês, chemical solution deposition). Filmes epitaxiais com elevada qualidade cristalina foram obtidos em substrato de SrTiO3 (100) e filmes com crescimento texturizados e policristalinos foram obtidos em substrato de safira e sílica. Foi possível observar que o método físico PLD produziu filmes com maior grau de epitaxia em comparação ao CSD, no entanto, apresentaram maior desordem a curto alcance. Um ponto importante é que, a partir da variação das condições como temperatura, substrato e composição é possível variar a ordem a curto alcance e longo alcance em pós e filmes finos, bem como nas características morfológicas dos filmes.