Esquemas de diagnóstico auxiliado por computador (CAD, do inglês \"computer aided diagnosis\") têm sido desenvolvidos com o objetivo de fornecer subsídios para a detecção precoce do câncer de mama. Nesses esquemas, técnicas de processamento de imagens são utilizadas para indicar a existência de estruturas suspeitas em imagens mamográficas. Entre essas estruturas estão os agrupamentos de microcalcificações (clusters), cuja existência é indicativo da necessidade de uma inspeção mais minuciosa no local. As imagens de mamas densas, características principalmente de mulheres jovens, constituem, no entanto, um desafio para esses esquemas devido ao baixo contraste entre as estruturas de interesse e os demais tecidos representados na imagem mamográfica. Nesta pesquisa, portanto, foram feitas investigações sobre as características das imagens radiográficas de mamas densas, a partir das quais foram desenvolvidas técnicas de realce de contraste que, somadas a outras técnicas de processamento digital, proporcionaram um desempenho mais apropriado de um esquema de processamento para detecção de c1usters. Foram ainda elaboradas técnicas que permitam o trabalho com uma resolução de contraste mais adequada, além de outras que consideram alguns dos parâmetros físicos envolvidos na obtenção das imagens e procedimentos para reduzir diagnósticos falsos-positivos. Os resultados registrados nos testes com diferentes conjuntos de imagens de uma base de dados montada para esse projeto indicam que a combinação das técnicas desenvolvidas permite incrementar o desempenho de um esquema de processamento para detectar agrupamentos de microcalcificações, possibilitando a identificação de estruturas em imagens de baixo contraste, não detectadas em processamento convencional antes do realce de contrate. Como efeito, essa investigação mostra a possibilidade de esquemas CAD em mamografia atingir agora desempenho satisfatório na detecção de microcalcificações em imagens de mamas densas. / Computer-aided diagnosis (CAD) schemes have been developed intended to provide information for early detection of breast cancer. Image processing techniques are used in these schemes in order to indicate suspicious structures in mammographic images. Among these structures there are clustered microcalcifications, which usually drive to a more detailed examination in the location where they are. Images corresponding to dense breasts, which are characteristic mainly of young women, are however a challenge to CAD schemes due to the low contrast between the structures of c1inical interest and the other tissues registered on the film. Therefore, investigations were performed in this work on the characteristics of dense breasts radiographic images, from which contrast enhancement techniques were developed. These procedures were joined to other digital processing techniques to provide a better performance for a processing scheme intended to clusters detection. In addition, techniques which allow to work with a more suitable contrast resolution and others which take into account some of the physical parameters involved in the image acquisition process were developed together with a procedure designed to reduce false positive diagnoses. The results obtained during tests with different images sets from a data base developed for this research indicate that combining all the techniques developed here allow to improve the performance of a processing scheme designed to detect microcalcifications clusters, and it also allows to distinguish some of these structures in low contrast images, which were not detected in conventional processing before the contrast enhancement. As consequence, this investigation shows the possibility now for CAD schemes in mammography reaches a better performance in microcalcifications detection in dense breasts images.

A reparação de danos provocados pelo homem aos ecossistemas não é recente no Brasil. Plantações florestais têm sido estabelecidas desde o século XIX sem, no entanto, até recentemente, terem vínculos estreitos com concepções teóricas, sendo executadas normalmente como uma prática de plantio de mudas, com objetivos muito específicos, como controle de erosão, estabilização de taludes, melhoria visual, entre outros. Com o desenvolvimento dos conceitos e teorias ecológicos, sobretudo nos últimos cinqüenta anos, os programas de manejo e restauração florestal têm deixado de ser meras aplicações de práticas agronômicas e silviculturais, para buscar a reconstrução de interações ecológicas da comunidade, ou seja, os projetos de restauração estão deixando de ser o plantio de um amontoado de indivíduos e passando a considerar o potencial de auto-regeneração do ambiente. Este trabalho foi desenvolvido em um sítio degradado da Reserva Legal do aeroporto municipal de Registro (SP), cidade situada no Vale do Ribeira, com o objetivo de avaliar o potencial da transferência de banco de propágulos alóctone em recuperar áreas degradadas. O uso de banco de propágulos como método de recuperação de áreas degradadas é uma prática já bastante utilizada para a recuperação de áreas mineradas em todo o mundo. Nesses casos, o banco é comumente espalhado na área total, normalmente com grande espessura (20 - 50 cm). Neste trabalho foi testada a deposição do banco de propágulos em sulcos, partindo-se da premissa que esta técnica pode permitir que um mesmo volume de banco seja capaz de recuperar uma área degradada maior, aumentando seu rendimento. Assim, na área experimental foi testado o potencial regenerativo do banco de propágulos através de quatro tratamentos: testemunha (Controle), Calcário (Ca), Calcário + Nitrogênio inicial (Ca+Ni) e Calcário + Nitrogênio em cobertura (Ca+Nc). Cada tratamento foi alocado em um sulco de dimensões 0,3m X 0,3m X 20,0m (1,8 m³), e repetido quatro vezes, totalizando 16 sulcos (28,8 m³). A coleta da serapilheira e do solo até uma profundidade de 20 cm, que corresponde ao banco de propágulos aqui estudado, foi feita em 12 parcelas amostrais de dimensão 3,0mX3,0mX0,2m (1,8m³), distribuídas a esmo nas manchas da floresta classificadas em estágios médio e avançado de regeneração, na faixa de floresta condenada à supressão. O solo e a serapilheira da parcela foram revolvidos com enxada. Este material foi acondicionado em sacos de ráfia de 100L. Entretanto, cada saco continha apenas 60L (~70Kg). Para obedecer este padrão, utilizou-se uma lata de tinta de 18L, estabelecendo-se 3,3 latas por saco. Este volume estabeleceu uma média de 21,33 sacos por parcela. Foi coletado um total de 256 sacos. Estes sacos foram distribuídos em 16 sulcos, com 16 sacos por sulco. Em um ano, iniciado em Setembro de 2006, foram coletados dados de emergência, crescimento, recrutamento e mortalidade dos indivíduos arbustivo-arbóreos. Durante os 12 meses de monitoramento, surgiram 538 indivíduos de 40 espécies, apenas desses hábitos, em uma área de 96m². Aos 12 meses, 409 indivíduos estavam vivos. O tratamento Controle foi aquele que apresentou as maiores quantidades de indivíduos e espécies, apresentou menor número de 7 indivíduos mortos e menores taxas de crescimento. Os demais tratamentos indicaram que os insumos favoreceram apenas o crescimento, tendo havido efeito neutro ou negativo sobre os outros parâmetros avaliados. / The relief of the human damage caused on natural ecosystems is not recent in Brazil. Forest plantations have been established since XIX century, although only recently it have been based on a conceptual framework; before that plantations were planned to attend specific purposes, such as eroding control, embankment slopes, visual improvement, among others. The development of ecological concepts and theories, mostly in the last 50 years, promoted relevant changes on restoration projects, which evolved to consider the environment\'s self-regeneration potential. This study was developed at a degraded site within the Legal Reserve of the airport of Registro, SP, located at Ribeira Valley. The main purpose was to evaluate the alochtonous seed bank transference potential as a restoration technique. Transference of alochtonous propagules is an usual technique for mining areas restoration around the world. In these cases the propagules bank (topsoil) is usually spread as a thick layer (20 - 50cm) over the target area. Here the topsoil was spread over sulcos (arroyos, wales), accepting the idea that with this technique a certain amount of topsoil may recover a larger area, enhancing its income/output. Thus, the regenerative potential of the topsoil was tested over four experimental treatments: attester (Control), Calcareous/Limestone (Ca), initial Calcareous + Nitrogen (Ca+Ni) and on surface Calcareous + Nitrogen (Ca+Nc). Each treatment was allocated into 0.3m x 0.3m x 20m (1.8m3) furrows and repeated four times, in a total of 16 furrows (28.8m3). Topsoil was collected at a 20cm depth, sampled by twelve 3.0m x 3.0m x 0.2m (1.8m2) plots, distributed without direction within secondary forest remnants in late sucessional stages, in the logged area. Topsoil was removed with hoe and bagged into 100L raffia bags. Therefore, each bag was fulfilled with 60L (~70Kg) only. To follow the pattern, 18L paint tin box were used to keep an average number of 3,3 paint tin box per bag. This volume correspond to an average of 21.33 sacos per plot. From September 2006 to September 2007, emergence, growth, recruitment and mortality were monitored. A total of 538 individuals (shrubs and trees) of 40 species were recorded, in a total area of 96m2. After 12 twelve months 409 individuals survived. Control treatment presented the highest individuals and species quantities, the lowest growth rates and mortality. The other treatments revealed that fertilizers indulge growth, with neutral or negative effects over demais evaluated parameters.

Orientadores: Fernando Roberto Martins, Roque Cielo-Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-11T07:12:22Z (GMT). No. of bitstreams: 1 Rochelle_AndreLuisCasarin_M.pdf: 1478945 bytes, checksum: a4104c9f3c9454316c0218d7e704cc74 (MD5) Previous issue date: 2008 / Resumo: A Floresta Atlântica é um ecossistema complexo, exibindo áreas com mais de 200 espécies de árvores coexistindo em um único hectare. Variações topográficas, principalmente em pequenas escalas, parecem ter forte influência sobre a diversidade, porque estão relacionadas com o processo de formação do substrato e com a disponibilidade de água e nutrientes do solo. Este trabalho investigou a relação entre variáveis microtopográficas e a estrutura da comunidade arbórea em 1 hectare de Floresta Atlântica, no Parque Estadual Serra do Mar, Ubatuba, SP. No capítulo 1, testamos as hipóteses que microvariações topográficas aumentam a diversidade de espécies arbóreas e que microhábitats côncavos possuem maior diversidade que microhábitats convexos, e no capitulo 2, que microhábitats côncavos detêm mais biomassa que microhábitats convexos devido ao predomínio de processos de sedimentação neste tipo de microrrelevo. No capítulo 3, apresentamos uma descrição fitossociológica, discutindo sua diversidade em contextos regionais e continentais. Alocamos 100 parcelas contíguas de 10 x 10 metros (S23º21¿59.8¿¿W45º05¿02.8¿) e etiquetamos, medimos (PAP e altura) e identificamos todas as árvores (PAP>15 cm). Para cada parcela, medimos a inclinação do terreno e calculamos a biomassa acima do solo (BAS) e o índice de convexidade (IC), que é considerado indicador da disponibilidade de água e nutrientes no solo, pois processos erosivos predominam em áreas convexas, tornando-as ambientes mais secos, enquanto nas áreas côncavas predominam processos de sedimentação e acúmulo de água e nutrientes. 51 parcelas são convexas e 49 côncavas. O solo das parcelas côncavas foi significativamente mais úmido que das convexas. Encontramos 1881 indivíduos de 206 espécies, 102 gêneros e 48 famílias (H¿= 4,48 nats.ind-1), sendo 1578 árvores (83,89%), 237 palmeiras (12,59%), 8 samambaias arborescentes (0,42 %) e 58 mortos (3,08 %). Euterpe edulis obteve o maior IVI. Myrtaceae (42), Rubiaceae (18) e Fabaceae (15) foram as famílias mais ricas. Ocorreram duas espécies novas. A diversidade (H¿= 4,48 nats.indivíduo-1) está entre as maiores do Brasil. A BAS estimada foi de 255,553 Mg.ha-1. 804 árvores (104,703 Mg.ha-1) nas côncavas e 1077 árvores (150,850 Mg.ha-1) nas convexas. A BAS não mostrou correlação com o IC ou inclinação e apresentou distribuição aleatória, assim como as grandes arvores, que representam sua maior proporção. A diversidade não mostrou correlação com a inclinação e com heterogeneidade microtopográfica. As parcelas convexas apresentaram mais indivíduos e diversidade, contrariando nossas hipóteses e os resultados de outros autores que diversidade é negativamente correlacionada com posições mais altas da encosta. Argumentamos que em florestas com alta pluviosidade, a umidade do solo poderia atuar como fator restritivo ao estabelecimento dos indivíduos, atuando concomitantemente a várias contrastantes condições microclimáticas imposta pela microtopografia, tais como período de exposição à luz, temperatura e evaporação do solo e do ar e taxas de acúmulo e decomposição de serrapilheira e matéria orgânica, que poderiam atuar como filtros ambientais afetando a germinação e o estabelecimento. Nossos resultados mostraram que heterogeneidade ambiental nem sempre aumenta a diversidade de espécies arbóreas e que as espécies exibem diferentes tolerâncias por hábitat, evidenciando os processos de montagem por nichos em comunidades arbóreas tropicais. Palavras-chave: filtros ambientais, heterogeneidade microtopográfica, modelo de montagem por nichos, microrrelevo, fitossociologia, micro-hábitat / Abstract: Atlantic rainforests are complex ecosystems with areas harboring more than 200 species in a single hectare. Micro-topographic variations appear to be associated with tree species diversity because they are related with the process of soil origin and soil water and nutrient availability. We investigated the relationships between fine-scale micro-topographic variables and tree community structure in 1-ha of Atlantic rainforest at SE Brazil. In chapter 1 we tested the hypotheses that concave sites exhibit higher tree species diversity than convex sites and tree species diversity increase with small-scale microtopographic heterogeneity and in chapter 2, that concave micro-habitats harbor more biomass than convex micro-habitats due to the accumulation processes predominating in the concave microtopography. In chapter 3, we described the tree community structure and compared with other surveys. The sampling area (S23º21¿59.8¿¿O45º05¿02.8¿) was a grid of one hundred 10 x 10 m contiguous plots where all trees with DBH > 4.8 cm were tagged, measured (DBH and height) and identified. In each plot, we measured slope inclination, estimated the above-ground biomass (AGB), and calculated the index of convexity (IC), which is considered to reflect the soil water and nutrient availability because erosive processes predominate in convex areas, implying in drier and less fertile micro-sites, whereas accumulation processes prevail in concave areas, producing moister and more fertile micro-sites. 51 plots are convex and 49 are concave. Soil in concave sites was significantly (p=0.04) moister than in convex. We sampled 1881 trees of 206 species, 102 genera and 48 families (H¿= 4.48 nats.inds-1). 1578 stems were trees (83,89%), 237 palms (12,59%), 8 ferns (0,42 %) and 58 standing dead trees (3,08 %). Euterpe edulis had the highest IVI. Myrtaceae (42), Rubiaceae (18) e Fabaceae (15) were the richest families. We found two new species. The diversity (H¿= 4.48 nats.indivíduo-1) is among the highest recorded in Brazil. The estimated AGB was 255.553 Mg C.ha-1. 804 trees (104.703 Mg C.ha-1) in concave plots and 1077 trees (150.850 Mg C.ha-1) in convex. AGB was not correlated with IC or inclination and had a random distribution because the greatest proportion of AGB was yielded by large trees, which also had a random pattern. Diversity had no correlation with inclination and micro-topographic heterogeneity. Convex plots harbored significantly more individuals and species than concave plots, which contradicted our hypotheses that expected a negative correlation between diversity (and AGB) and convexity and other author¿s findings that diversity is negatively correlated with higher positions on slope. We argue that in forests with abundant rainfall and without a dry season, the high soil water content could restrain the establishment of some individuals, together with several microclimatic conditions imposed by the microtopography, such as sunlight exposure, ground and air temperature and evaporation, and litter and organic matter accumulation and decomposition rates, that could act as environmental filters and affects species germination and performance. Our results show that environmental heterogeneity does not always increase tree species diversity and that species do have habitat preferences and tolerances evidencing niche assembly processes in tropical tree communities. Keywords: environmental filters, microtopographic heterogeneity, niche-assembly model, micro-relief, phytosociology, micro-habitats, concave, convex / Mestrado / Mestre em Biologia Vegetal

Orientador: Carlos Alfredo Joly / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-20T21:03:27Z (GMT). No. of bitstreams: 1 Tavares_AndreadaCostaMarques_M.pdf: 1534689 bytes, checksum: 145f2e42ac5f923e0cd3fe2b46bbc9b9 (MD5) Previous issue date: 2011 / Resumo: Estudos de comunidades em biologia floral e polinização são muito importantes para o entendimento da estrutura e do funcionamento dos ecossistemas. A Floresta Atlântica da Serra do Mar possui diferentes fisionomias que refletem as diferentes comunidades ocorrentes ao longo do gradiente de altitude. Esse estudo foi realizado em Floresta Ombrófila Densa Submontana, em Ubatuba - SP e é parte integrante do Projeto Temático Biota Gradiente Funcional - FAPESP. O objetivo geral desse trabalho foi investigar a Floresta Ombrófila Densa Submontana da Mata Atlântica quanto aos atributos florais e polinização. Foram estudadas as especies angiospermas encontradas em floração durante um ano, registrando seus atributos e visitantes florais, a forma de vida e estrato, então as síndromes de polinização foram inferidas. Foram registradas 95 espécies ao todo, de 39 famílias. Fabaceae e Rubiaceae apresentaram maior numero de espécies em flor (oito espécies cada), mas a maioria das famílias apresentou poucas espécies. Os atributos florais predominantes foram: tubo e inconspícuo como tipos morfológicos; tamanho pequeno; as cores mais frequentes foram branco e amarelo; como recurso, néctar seguido de pólen. Em 26 espécies observou-se visitação de animais de vários tipos, principalmente abelhas, beija-flores e borboletas e em alguns casos a polinização pode ser confirmada. A síndrome de polinização mais frequente na comunidade foi melitofilia, seguido de ornitofilia e sistemas mistos foram observados em 21,1% das espécies. A forma de vida mais frequente foi arbórea, seguido de liana e epífita; o estrato onde se observou maior número de espécies florindo foi o dossel. As distribuições dos recursos florais e das síndromes de polinização por formas de vida, estrato e temporal foram analisadas. A maior frequencia de plantas florindo foi observada durante a estação mais quente e chuvosa, de out/2009 a jan/2010. As principais diferenças espaciais e temporais ocorreram entre as síndromes de melitofilia e ornitofilia. Essa fitofisionomia apresentou algumas peculiaridades em relação a outras fisionomias e a outros ecossistemas, sendo, portanto, de grande importância a conservação das interações ecológicas dessa formação vegetal para a manutenção da grande biodiversidade da Floresta Atlântica / Abstract: Studies on floral biology and pollination at community level are very important to understand the ecosystems structure and functioning. Atlantic Forest at Serra do Mar has different physiognomies that reflect different communities along altitudinal gradient. This study was done in Submontane Ombrophilous Dense Forest, at Ubatuba - SP and integrates the Thematic Project Biota Gradiente Funcional - FAPESP. The general purpose of this study was to investigate the Submontane Ombrophilous Dense Forest of Atlantic Forest about floral traits and pollination. The angiosperms species found flowering during one year was studied, registering its floral traits, floral visitors, life forms and strata, so the pollination syndromes were deduced. 95 species was registered of 39 families. Fabaceae e Rubiaceae had the highest number of species in bloom (eight species each), but most families had few species. Predominant floral traits were: tube and inconspicuous as morphological types; small size; most common colors were white and yellow; as resource, nectar followed by pollen. In 26 species, several types of animals were observed visiting flowers, mainly bees, hummingbirds and butterflies, and in some cases the pollination was confirmed. The most frequent pollination syndrome in the community was melittophily, followed by ornithophily and mixed systems were observed in 21.1% of the species. The most frequent life form was tree, after liana and epiphyte; the strata where was observed major number of species was canopy. Distributions of floral resources and pollination syndromes in life forms, strata and temporal was analyzed. The higher frequency of plants flowering was observed during the hot and wet season, from oct/2009 to jan/2010. The main special and temporal differences occurred between melittophily and ornithophily syndromes. This fitophysiognomy showed some particularities in relation to other physiognomies and other ecosystems, and therefore are very important the conservation of ecological interactions of this vegetation type to maintain the great biodiversity of the Atlantic Forest / Mestrado / Biologia Vegetal / Mestre em Biologia Vegetal

Les conditions thermodynamiques régnant au sein des planètes géantes telles que Jupiter, Saturne et bon nombre des exoplanètes découvertes quotidiennement, impliquent que les interactions entre particules – atomes, ions, électrons – sont prépondérantes dans les enveloppes planétaires, principalement composées d'hydrogène et d'hélium, et déterminent les propriétés mécaniques et thermiques de ces objets. La caractérisation de ces plasmas denses est donc cruciale pour comprendre la structure et l'évolution de ces planètes géantes. Les simulations ab initio, utilisant la théorie de la fonctionnelle de la densité, ont montré leurs performances pour la caractérisation des espèces pures dans leur phase plasma dense, en reproduisant correctement les résultats des expériences de chocs par laser haute-puissance. Néanmoins, des écarts importants perdurent entre modèles planétaires et observations. Ils sont attribués à la non-idéalité du mélange H-He et de possibles transitions de phase. Dans ce travail de thèse, ces méthodes numériques ab initio ont été appliquées au cas des mélanges H-He. L'étude thermodynamique a révélé des déviations sensibles par rapport aux prédictions obtenues pour des mélanges idéaux. Par ailleurs, les calculs des propriétés de transport (conductivité électrique, thermique, propriétés optiques...) ont montré une transition isolant-conducteur du mélange, notamment par l'ionisation de l'hydrogène. Celle-ci s'accompagne, dans un certain domaine de paramètres, d'une séparation de phase entre l'hydrogène conducteur et l'hélium neutre. Ces calculs ont également permis d'établir des diagnostics pour les expériences laser, afin de pouvoir corroborer cet ensemble de résultats et obtenir, à terme, une équation d'état fiable du mélange H-He, applicable aux planètes géantes. / The thermodynamical conditions inside the giant planets - like Jupiter, Saturn or many of the daily discovered exoplanets – are such that the interactions between particles – atoms, ions, electrons – are highly dominant in the physics of giant planets envelope s, mostly made of hydrogen and helium in a plasma phase. The heat and mechanical properties of these planets are mainly determined by these interactions. Thus, it is of crucial interest to study these dense plasmas to understand the structure and the evolution of the giant planets. The dense plasma phase of the pure compounds has been successfully characterized by ab initio simulations using density functional theory. For instance, they correctly reproduced the results obtained in high-power laser chock experiments. Nevertheless, large discrepancies remain between planetary models and observations. A proposed hypothesis is a strong influence of the H-He mixture non-ideality and possible phase separations. In this work, these ab initio numerical methods have been applied to the H-He mixtures. The thermodynamical study has shown sensitive deviations from ideal mixtures. The estimates of the transport properties (electrical and heat conductivities, optical properties...) indicate an insulator-conductor transition in the mixture, associated with hydrogen ionization. In some conditions, demixing of conducting hydrogen and neutral helium has also been observed. These computations have allowed us to determine pathways to verify our results through laser experiments. This is the first step in the establishment of a reliable equation of state of H-He mixtures, usable in giant planets modeling.

Dense flows of grains are commonplace throughout natural and industrial environments, from snow-avalanches down the sides of mountains to flows of cereal down chutes as it is transported from one part of a factory to another. A ubiquitous feature in all of these flows is their ability to separate the different grain types when shaken, stirred, sheared or vibrated. Many flows are sheared through gravity and these flows are particularly efficient at segregating particles based on their size, with small particles percolating to the bottom of the flow and large particles collecting at the top. Within this mechanism, an asymmetry between the large and small particles has been observed, with small particles percolating downwards through many large particles at a faster rate than large particles rise upwards through many small particles. This alternative format thesis presents a revised continuum model for segregation of a bidisperse mixture that can account for this asymmetry. A general class of asymmetric segregation flux functions is introduced that gives rise to asymmetric velocities between the large and small grains. Exact solutions for segregation down an inclined chute, with homogenous and normally graded inflow conditions, show that the asymmetry can significantly enhance the distance for complete segregation. Experiments performed using a classical shear-box with refractive index matched scanning are able to quantify the asymmetry between large and small particles on both bulk and particle scales. The dynamics of a single small particle indicate that it not only falls down faster than a single large particle rises, but that it also exhibits a step-like motion compared to the smooth ascent of the large grain. This points towards an underlying asymmetry between the different sized constituents. The relationship between the segregation-time and the volume fraction of small grains is analysed, and solutions presented for the steady-state balance between segregation and diffusive remixing. These help to show the good agreement between the asymmetric model and experimental data. Segregation at the front of natural avalanches produces a recirculation zone, known as a `breaking size-segregation wave', in which large particles are initially segregated upwards, sheared towards the front of the flow, and overrun before being resegregated again. Solutions for the structure of this recirculation zone are derived using the asymmetric flux model, revealing a novel `lens-tail' structure. Critically, it is seen that a few large particles starting close to the bottom of the flow are swept a long way upstream and take a very long time to recirculate. The breaking size-segregation waves highlight the important interplay between segregation and the bulk velocity field. The properties of flowing monodisperse grains are explored through experiments on a cone that produce a beautiful radial fingering pattern. Equations developed in a conical coordinate system reproduce the measured linear relationship between fingering radius and initial flux, whilst also predicting the slowing and thinning dynamics of the flow. Overall, these results illustrate the complex nature of the granular rheology and provide perspectives for future modelling of segregation in dense granular flows.

Scientific Computation provides a critical role in the scientific process because it allows us ask complex queries and test predictions that would otherwise be unfeasible to perform experimentally. Because of its power, Scientific Computing has helped drive advances in many fields ranging from Engineering and Physics to Biology and Sociology to Economics and Drug Development and even to Machine Learning and Artificial Intelligence. Common among these domains is the desire for timely computational results, thus a considerable amount of human expert effort is spent towards obtaining performance for these scientific codes. However, this is no easy task because each of these domains present their own unique set of challenges to software developers, such as domain specific operations, structurally complex data and ever-growing datasets. Compounding these problems are the myriads of constantly changing, complex and unique hardware platforms that an expert must target. Unfortunately, an expert is typically forced to reproduce their effort across multiple problem domains and hardware platforms. In this thesis, we demonstrate the automatic generation of expert level high-performance scientific codes for Dense Linear Algebra (DLA), Structured Mesh (Stencil), Sparse Linear Algebra and Graph Analytic. In particular, this thesis seeks to address the issue of obtaining performance on many complex platforms for a certain class of matrix-like operations that span across many scientific, engineering and social fields. We do this by automating a method used for obtaining high performance in DLA and extending it to structured, sparse and scale-free domains. We argue that it is through the use of the underlying structure found in the data from these domains that enables this process. Thus, obtaining performance for most operations does not occur in isolation of the data being operated on, but instead depends significantly on the structure of the data.

During the last three decades, the significant increase in electricity demand, and its consequences, has appeared as a serious concern for the utility companies, but no major changes have been applied to the conventional power grid infrastructure. Recently, researchers have identified efficient control and power distribution mechanisms as the immediate challenges for conventional power grids. The next step for conventional power grid towards the Smart Grid is to provide energy efficiency management along with higher reliability via smart services, in which the application of Information and Communication Technology (ICT) is inevitable. ICT introduces powerful tools to comply with the smart grid requirements. Among various ICT properties, the telecommunication network plays a key role for providing a secure infrastructure. The two-way digital communication system provides an interaction between energy suppliers and consumers for managing, controlling and optimizing energy distribution. We can also define the smart grid as a two-way flow of energy and control information, where the electricity consumers can generate energy using green energy resources. The main objective of this thesis is to select an effective data communication infrastructure to support the smart grid services by considering a hybrid wireless and optical communication technologies. Radio-over-Fibre (RoF) networks are considered as a potential solution to provide a fast, reliable and efficient network backbone with the optical access network integration and the flexibility and mobility of the wireless network. Therefore, we adopt the integration of RoF to Passive Optical Network (PON) as a broadband access network to transmit smart grid data along with the Fiber to the Home/Building/Curb (FTTx) traffic through the shared fibre, and utilizing Wavelength Division Multiplexing (WDM). Finally, we present and analyze the simulation results for the aforementioned infrastructure based on our enhanced ROF-PON integration model.

Dense medium separation (DMS) plants are typically used to beneficiate run-of-mine (ROM) coal in coal metallurgy. These plants normally make use of a dense medium cyclone as the primary processing unit. Because of the deviations in the ROM quality, the production yield and quality become difficult to maintain. A control system could benefit such operations to maintain and increase product throughput and quality. There are many different methods for developing a control system in a metallurgical operation; however, what is most fundamental is the use of a mathematical model to design a controller. For this reason, a first principle dynamic mathematical model has been developed for a DMS circuit. Each unit operation is modelled individually, then integrated together to form the complete system. The developed DMS circuit dynamic model is then used to simulate the process. It is also found that most models developed for DMS operations typically make use of steady-sate analysis and that very little literature is available on dynamic models of this kind. Difficulties that arise when validating a model in metallurgical processes are insufficient measurement points or the challenges in measuring certain variables, such as physical properties (e.g. particle size) or chemical components (e.g. ash percentage). This paper also explains how the Runge-Kutta approximation can be used in simulating DMS unit processes with intermediate online measurements that may be available. This can ultimately assist in verifying the accuracy of the simulation. One of the other problems that can occur when developing models from first principles is the estimation of model parameters. Specifically when non-linear state-space relationships are developed, one must ensure that there is a unique solution for the parameters in question. A method employing parameter identifiability is also presented in this dissertation to illustrate its use. In addition the process of estimating parameters is explained and illustrated. Copyright / Dissertation (MEng)--University of Pretoria, 2010. / Electrical, Electronic and Computer Engineering / unrestricted

Orientador: Marcos Pereira Marinho Aidar / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-22T05:38:38Z (GMT). No. of bitstreams: 1 Manarin_EwertonCaltran_M.pdf: 9106258 bytes, checksum: d63841eee1497eafd2cd46024a281569 (MD5) Previous issue date: 2013 / Resumo: Este trabalho avaliou a fixação biológica de nitrogênio (FBN) por leguminosas e cianobactérias de vida livre na Floresta Ombrófila Densa Atlântica. Nódulos radiculares de leguminosas presentes em parcelas de 1 hectare foram amostrados para as fisionomias de Floresta Ombrófila Densa de Terras Baixas (FTB) e na Floresta Ombrófila Densa Montana (FM), localizadas em diferentes altitudes. A atividade da enzima nitrogenase dos nódulos foi avaliada através da atividade de redução de acetileno. FTB apresentaram a maior quantidade de nódulos e maior atividade da enzima nitrogenase em relação à FM. A taxa anual de FBN pelas leguminosas foi estimada em 2,06 kg N ha-1 e 0,230 kg N ha-1 para FTB e FM, respectivamente. A FBN apresentou os maiores valores no outono e os menores no inverno para a FTB. E maiores valores no outono e primavera para a FM. Seis estirpes de rizóbios isolados da floresta estudada tiveram sua capacidade de nodulação testada em experimento de casa de vegetação com a leguminosa Inga sessilis, que apresentou capacidade de se associar formando nódulos com cincos isolados da floresta, e com mais quatro isolados usados como controle, se mostrando uma leguminosa com baixa especificidade com seu simbionte. Cianobactérias de vida livre tiveram a FBN medidas em trechos intactos e trechos antropizados na FM. Estes organismos foram encontrados na superfície de solos e rochas em áreas expostas ao sol e sob a forma de colônias de Nostoc sp e de crostas, associadas com outros organismos. As medidas de FBN foram feitas através do ensaio de redução de acetileno em consórcio com técnicas isotópicas. As formas coloniais apresentaram maior atividade de FBN que as formas crostosas, e em ambas, a atividade foi maior no inverno que no verão. A FBN foi maior para trechos antropizados, 127 e 48 g N m-2 ano-1 para coloniais e crostosas, respectivamente e de 46 e 30 g N m-2 ano-1 para coloniais e crostosas de locais intactos, respectivamente. As FBN por leguminosas e cianobactérias para as áreas intactas de floresta se mostraram baixas, mas estão de acordo com o esperado para florestas maduras. Estes organismos provavelmente aumentam suas as taxas de FBN quando a floresta sofre distúrbio, assim como foi detectado para as cianobactérias em trechos antropizados / Abstract: This study evaluated rates of biological nitrogen fixation (BNF) by legumes and free-living cyanobacteria in Atlantic Rainforest. Legume root nodules found in 1 hectare plots were sampled for the Lowland physiognomy (LP) and Mountain physiognomy (MP), located at different altitudes. The nitrogenase enzyme activity of nodules was assessed by acetylene reduction assay. LP had the highest number of nodules and greater activity of the nitrogenase regarding MP. The annual rate of BNF by legumes was estimated at 2.06 kg N ha-1 and 0.230 kg N ha-1 for LP and MP, respectively. The BNF had the highest values in autumn and lowest in winter for LP. And higher values in autumn and spring for MP. Six strains of rhizobia isolated from the studied forest had their nodulation capacity tested in a greenhouse experiment with the legume Inga sessilis, which showed ability to form nodules with five strains, and with over four isolates used as controls, showing that this legume specie has a low specificity with its symbiote. Free-living cyanobacteria had BNF measured in intact and anthropized sites of the MP. These organisms were found in surface soils and rocks in areas exposed to the sun and in the form of colonies of Nostoc sp and crusts associated with other organisms. The measurements were made using acetylene reduction assay in consortium with isotopic techniques. Colonial forms showed higher activity than crust forms, and for both, the activity was higher in winter in comparison to summer. The BNF was higher for anthropized sites of the forest, 127 and 48 g N m-2 year-1 for colonial and crusted, respectively, and for intact sites, 46 and 30 g N m-2 year-1 for colonial and crusted, respectively. BNF by legumes and cyanobacteria in intact forest were low, but are consistent with expected for mature forests. These organisms probably increase their rates of BNF in disturbed conditions of the forest as well as detected for cyanobacteria in anthropized sites / Mestrado / Biologia Vegetal / Mestre em Biologia Vegetal