Rising global energy demands have led to an increase in demand for clean, sustainable energy. A leading technology for reducing greenhouse gas (GHG) emission for existing coal-power infrastructure is gasification, which has sparked an interest in reactor modelling for design and performance analysis. Reduced order models (ROMs) have seen an increase in popularity for entrained flow gasifiers, as they offer a low-computational alternative to conventional computational fluid dynamic (CFD) modelling while maintaining the integrity of important operational parameters, such as carbon conversion and syngas yield. However, ROMs require more physical parameter inputs than are normally required for CFD modelling, such as the geometry of the gas-solid jet (specifically the jet half-angle). Experiments were conducted to understand the relation between the required input parameters for ROMs, such as fuel flow rate, transport gas flow rate, and jet half-angle, and develop useful correlations for ROM systems. A new configuration for pneumatic conveying was developed and tested at the pilot-scale system at NRCan CanmetENERGY. It was used to study the pneumatic conveying of pulverized fuels, specifically the influence of operating parameters such as pressure drop and gas flow rates on the fuel flow rate, and the geometry of the gas-solid fuel jet (notably the jet half-angle) injected into the gasifier. The mean fuel flow rate of pulverized fuels was shown to increase with increasing pressure drop and with decreasing gas flow rates in the fuel transfer line. The jet half-angle was shown to increase as the solid loading ratio in the jet core was decreased. Finally, the relative fuel flow variability was observed to be significantly influenced by the design of the pneumatic conveying system, with the fluctuations increasing with increasing pressure drop and with decreasing gas flow rate, similar to the mean flow rate.

A software program was written that implements a finite element analysis (FEA) solution as the basis of an optimization function used for guiding the inverse design problem of aligning fibres, minimizing displacements in a fibre-reinforced polymer composite part in response to a given loading condition, for various part geometries. The FEA solution makes use of the superlinear RGNTet4 element, which includes 3 displacement and 3 rotational degrees of freedom at 4 nodes. Convergence testing verified the accuracy of the solver versus symbolic results for simple cases. Multivariate optimization over fibre orientations and volume fractions was carried out for a simple test case using the NLOpt nonlinear optimization library. Both derivative-free and gradient-based algorithms were tested. Low-Storage Broyden-Fletcher-Goldfarb-Shannon was the most effective algorithm. Four more complex cases were examined, and by varying fibre orientations, reductions of 48%, 66%, 58% and 32% were achieved in displacements at the loaded nodes.

The thesis covers a wide range of topics from the credit risk modeling with the emphasis put on pricing of the claims subject to the default risk. Starting with a separate general contingent claim pricing framework the key topics are classified into three fundamental parts: firm-value models, reduced-form models, portfolio problems, with a possible finer sub-classification. Every part provides a theoretical discussion, proposal of self-developed methodologies and related applications that are designed so as to be close to the real-world problems. The text also reveals several new findings from various fields of credit risk modeling. In particular, it is shown (i) that the stock option market is a good source of credit information, (ii) how the reduced-form modeling framework can be extended to capture more complicated problems, (iii) that the double t copula together with a self-developed portfolio modeling framework outperforms the classical Gaussian copula approaches. Many other, partial findings are presented in the relevant chapters and some other results are also discussed in the Appendix.

Currently there is no test to accurately predict stillbirth. It is proposed that better identification of placental disease in utero may aid stillbirth prediction and prevention. Pregnancies complicated by reduced fetal movement (RFM) have increased risk of stillbirth. We hypothesised that RFM is a symptom of placental dysfunction associated with adverse pregnancy outcome (APO) and that this placental abnormality can be detected antenatally and used to identify fetuses at highest-risk of APO. We tested this hypothesis by: 1) comparison of ex vivo placental structure and function between APO RFM pregnancies and their normal outcome RFM counterparts, 2) comparison of in utero estimates of placental size, vascularity, vascular and endocrine functions obtained from placental ultrasound, Doppler waveform analysis and maternal circulating placentally-derived hormone concentrations, to their ex vivo correlates and 3) examination of the predictive potential of placental biomarkers at the time of RFM.Ex vivo placentas from APO RFM pregnancies, compared to normal outcome RFM counterparts, were smaller (diameter, area, weight and volume, p<0.0001), less vascular (vessel number and density, p≤0.002), with arteries that were less responsive to sodium nitroprusside (p<0.05), and with aberrant endocrine function (reduced tissue content and/or release of human chorionic gonadotrophin (hCG), human placental lactogen (hPL) and soluble fms-like Tyrosine Kinase-1 (sFlt-1), p<0.03). Placental volume (PV) ex vivo correlated with sonographic estimated PV (p<0.004), hPL, hCG and placental growth factor (PlGF) concentrations in the maternal circulation (p<0.03). Ex vivo villous vessel number and density correlated with Doppler impedance at the umbilical artery free-loop (UAD-F, p=0.02) and intraplacental arteries (p<0.0001) respectively, whilst UAD-F impedance correlated with arterial thromboxane sensitivity (p<0.04). Examination of placental structure and function at the time of presentation with RFM identified 15 independently-predictive biomarkers. Three potential predictive models, incorporating measures of placental size (PlGF), endocrine function (sFlt-1), arterial thromboxane sensitivity and villous vascularity (UAD-F), were proposed. Using these models, sensitivity for APO was improved from 8.9% with baseline care (assessment of fetal size and gestation) to up to 37.5% at a fixed specificity of 99% (p<0.05). This series of studies shows that antenatal placental examination is possible and improves identification of pregnancies at highest risk of stillbirth in a high-risk population by up to 29%. Therefore such tests merit further development to prospectively assess their ability to predict and prevent stillbirth itself.

Cette thèse comprend trois sujets différents, tous en rapport à des problèmes de structures électroniques. Ces trois sujets sont présentés dans trois parties indépendantes.Cette thèse commence par une introduction générale présentant les problématiques et les principaux résultats.La première partie traite de la théorie de la fonctionnelle de la densité lorsqu'elle est appliquée aux modèles d'électrons avec spins polarisés. Cette partie est divisée en deux chapitres. Dans le premier de ces chapitres, nous introduisons la notion de N-représentabilité, et nous caractérisons les ensembles de matrices de densité de spin représentables. Dans le second chapitre, nous montrons comment traiter mathématiquement le terme de Zeeman qui apparaît dans les modèles comprenant une polarisation de spin. Le résultat d'existence qui est démontré dans (Anantharaman, Cancès 2009) pour des systèmes de Kohn-Sham sans polarisation de spin est étendu au cas des systèmes avec polarisation de spin.Dans la seconde partie, nous étudions l'approximation GW. Dans un premier temps, nous donnons une définition mathématique de la fonction de Green à un corps, et nous expliquons comment les énergies d'excitation des molécules peuvent être obtenues à partir de cette fonction de Green. La fonction de Green peut être numériquement approchée par la résolution des équations GW. Nous discutons du caractère bien posé de ces équations, et nous démontrons que les équations GW0 sont bien posées dans un régime perturbatif. Ce travail a été effectué en collaboration avec Eric Cancès et Gabriel Stoltz.Dans le troisième et dernière partie, nous analysons des méthodes numériques pour calculer les diagrammes de bandes de structures cristallines. Cette partie est divisée en deux chapitres. Dans le premier, nous nous intéressons à l'approximation de Hartree-Fock réduite (voir (Cances, Deleurence, Lewin 2008)). Nous prouvons que si le cristal est un insolant ou un semi-conducteur, alors les calculs réalisés dans des supercellules convergent exponentiellement vite vers la solution exacte lorsque la taille de la supercellule tend vers l'infini. Ce travail a été réalisé en collaboration avec Salma Lahbabi. Dans le dernier chapitre, nous présentons une nouvelle méthode numérique pour le calcul des diagrammes de bandes de cristaux (qui peuvent être aussi bien isolants que conducteurs). Cette méthode utilise la technique des bases réduites, et accélère les méthodes traditionnelles. Ce travail a été fait en collaboration avec Eric Cancès, Virginie Ehrlacher et Damiano Lombardi / This thesis contains three different topics, all related to electronic structure problems. These three topics are presented in three independent parts.This thesis begins with a general introduction presenting the problematics and main results.The first part is concerned with Density Functional Theory (DFT), for spin-polarized models. This part is divided in two chapters. In the first of these chapters, the notion of N-representability is introduced and the characterizations of the N-representable sets of spin-density 2X2 matrices are given. In the second chapter, we show how to mathematically treat the Zeeman term in spin-polarized DFT models. The existence of minimizers that was proved in (Anantharaman, Cancès 2009) for spin-unpolarized Kohn-Sham models within the local density approximation is extended to spin-polarized models.The second part of this thesis focuses on the GW approximation. We first give a mathematical definition of the one-body Green's function, and explain why methods based on Green's functions can be used to calculate electronic-excited energies of molecules. One way to compute an approximation of the Green's function is through the self-consistent GW equations. The well-posedness of these equations is discussed, and proved in the GW0 case in a perturbative regime. This is joint work with Eric Cancès and Gabriel Stoltz.In the third and final part, numerical methods to compute band-diagrams of crystalline structure are analyzed. This part is divided in two chapters.In the first one, we consider a perfect crystal in the reduced Hartree-Fock approximation (see (Cances, Deleurence, Lewin 2008)). We prove that, if the crystal is an insulator or a semi-conductor, then supercell calculations converge to the exact solution with an exponential rate of convergence with respect to the size of the supercell. This is joint work with Salma Lahbabi. In the last chapter, we provide a new numerical method to calculate the band diagram of a crystal (which can be either an insulator or a conductor). This method, based on reduced basis techniques, speeds up traditional calculations. This is joint work with Eric Cancès, Virginie Ehrlacher, and Damiano Lombardi

Submitted by Rafael Santana (rafael.silvasantana@ufpe.br) on 2017-07-17T18:07:37Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Dissert_GabrielaNakayama-BC.pdf: 1142106 bytes, checksum: 05e14be3f2549f59152b14cf743178b1 (MD5) / Made available in DSpace on 2017-07-17T18:07:37Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Dissert_GabrielaNakayama-BC.pdf: 1142106 bytes, checksum: 05e14be3f2549f59152b14cf743178b1 (MD5) Previous issue date: 2016-07-22 / CAPES / O design de moda explicita grande lacuna no que tange o acesso para pessoas com deficiência e/ou mobilidade reduzida. Além das questões de inclusão social, tem-se um cenário mercadológico carente no que diz respeito ao entendimento e atendimento de necessidades específicas desse público. Partindo do ideal do vestuário como uma extensão do próprio corpo é imprescindível a compreensão das demandas de seu usuário consumidor como elemento norteador no desenvolvimento de produtos. Levantam-se então questionamentos sobre o aporte projetual e metodológico, bem como seus entraves, presentes na formação do designer de moda. Em prol da compreensão desses contextos, a revisão literária pautou-se nas perspectivas relevantes sobre a deficiência e a mobilidade reduzida, a ergonomia, a representação do corpo no contemporâneo e o design de moda em suas características práticas e comunicacionais, bem como seu ensino no Brasil. A investigação buscou traçar um panorama que sustente a viabilidade do objetivo da pesquisa, a elaboração de ferramentas metodológicas que contribuam no processo de desenvolvimento de produtos de moda para pessoas com algum tipo de mobilidade reduzida. Amparando o embasamento teórico, um estudo analítico foi o aporte metodológico, abordando métodos das áreas de projeto, de design e da moda, além de referenciais da ergonomia, visando um entendimento macro dos processos projetuais. A compreensão das especificações projetuais necessárias para um desenvolvimento que englobe usuários com mobilidades reduzidas, focando na usabilidade e no conforto, resultou no delineamento de diretrizes projetuais que potencializam a otimização do processo de desenvolvimento de produtos de vestuário, visando a inclusão e a acessibilidade de consumidores com mobilidade reduzida, primordialmente no âmbito didático da moda. A ferramenta, além de proporcionar uma moda mais inclusiva, traz como resultados finais uma abordagem ergonômica e voltado ao conforto e, ainda que direcionada à mobilidade reduzida, denota uma flexibilidade projetual, permitindo sua aplicação para diferentes públicos findando em um produto coerente com questões de conforto e usabilidade. / The fashion design shows inssufiency regarding access for people with disabilities and / or reduced mobility. In addition to the issues of social inclusion, there is a gap in market scenario regarding understanding and meeting the needs of this audience. From the idea that clothing is as an extension of the own body, it is essential to understand the demands of their consumers as a guiding element in product development. Considering that, issues arise about project and methodological support, as well as their obstacles, present in fashion design bachelor’s degree graduations. In order to understand these contexts, the literature review was based on the relevant perspectives on disability and reduced mobility, ergonomics, the body representation in contemporary and fashion design, in their practices and communication features, as well as its teaching in Brazil. The study aimed to provide an overview to sustain the viability of the objective of the research, the development of methodological tools to contribute in the process of desinging fashion products for people with some kind of reduced mobility. Supporting the theoretical basis, an analytical study was the methodological approach, addressing methods of project, design and fashion fields, and ergonomics references, aiming at a macro understanding of the processes of the project. Understanding the project specifications required for a development that encompasses users with reduced mobility, focusing on usability and comfort, it resulted in the design of projectual guidelines that enhance and optimize the development of apparel products process, increasing inclusion and accessibility of consumers with reduced mobility, specially in the context of fashion design teaching. The tool, in addition to provide an inclusive fashion scenario, brings as a final result an ergonomic approach aiming confort and, although directed to reduced mobility, denotes a projetual flexibility, allowing its application to different audiences resulting in a coherent product in the matters of comfort and usability.

Orientadores: Ana Flávia Nogueira, Flávio Leandro de Souza / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-27T13:00:11Z (GMT). No. of bitstreams: 1 Carminati_SaulodoAmaral_M.pdf: 3434559 bytes, checksum: 5dc1e86f14ccc0bccd7264ae9b28c11e (MD5) Previous issue date: 2015 / Resumo: O Resumo poderá ser visualizado no texto completo da tese digital / Abstract: The Abstract is available with the full electronic digital document / Mestrado / Quimica Organica / Mestre em Química

Orientador: Juliano Alves Bonacin / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-27T15:22:06Z (GMT). No. of bitstreams: 1 Santos_PamylaLayenedos_M.pdf: 4212017 bytes, checksum: 32d8be4cbad15f721c18e5490e98cb35 (MD5) Previous issue date: 2015 / Resumo: O azul da Prússia (AP) é um dos mais antigos compostos de coordenação e pode ser utilizado na modificação de sensores eletroquímicos para a detecção de H2O2, o AP pode catalisar a redução do peróxido e por isso é conhecido como "artificial peroxidase". Entretanto, filmes de AP não apresentam boa estabilidade eletroquímica e alternativas como a obtenção de nanocompósito baseados em AP e grafeno podem ser utilizadas para contornar o problema. O grafeno é um material com alta condutividade, flexibilidade e resistência à tração, pode ser obtido pelo método de Hummers que consiste na redução do óxido de grafeno e neste caso é chamado de óxido de grafeno reduzido. Assim, o objetivo deste trabalho é a obtenção fotoquímica de um nanocompósito baseado em azul da Prússia (AP) e óxido de grafeno reduzido (rGO) que permite uma combinação das propriedades eletrocatalíticas do AP e condutoras do rGO para a aplicação em sensores eletroquímicos. Além disso, espera-se uma maior estabilidade eletroquímica deste material. Os materiais óxido de grafeno reduzido e azul da Prússia foram obtidos separadamente pelos métodos químicos e fotoquímicos com a utilização de LEDs. Os resultados mostraram vantagens do método fotoquímico como o controle da morfologia e do tamanho dos cristais de azul da Prússia. O grau de redução dos materiais baseados em grafeno foi controlado com o tempo de irradiação no LED e isso foi refletido em suas propriedades eletroquímicas, com uma resposta linear da corrente de pico em função do grau de redução. O nanocompósito foi obtido pelo método fotoquímico in situ, e isso foi comprovado pelas técnicas DRX, espectroscopias Raman e UV-Vis. As micrografias obtidas por FEG-SEM mostraram a presença de cubos de AP sobre toda a superfície do óxido de grafeno reduzido. Espera-se que a interação entre o AP e rGO permita uma maior estabilidade eletroquímica do material que será testado no sensoriamento de H2O2 / Abstract: Prussian blue is one of the oldest coordination compounds and can be used on the modification of electrochemical sensors for the detection of H2O2, PB can catalyze the reduction of hydrogen peroxide and, for that, it is known as "artificial peroxidase". However, PB films do not show good electrochemical stability and alternatives such as the obtention of nanocomposites based on PB and graphene can be used to work around this problem. Graphene is a material with high conductivity, flexibility and tensile strength. Graphene can be obtained by Hummers method, which consists of reducing graphene oxide, in which case it is called a reduced graphene oxide. The goal of this work is photochemically obtaining a nanocomposite based on Prussian blue (PB) and reduced graphene oxide (rGO) that allows a combination of the electrocatalytical properties of PB and high conductivity of rGO for use in electrochemical sensors. In addition, we expect a higher electrochemical stability of this material. Reduced graphene oxide and Prussian blue were obtained separately by chemical and photochemical methods using LED. The results show the advantages of photochemical method to control the morphology and size of Prussian blue crystals. The reduction extent of graphene-based material was controlled by the irradiation time of the LED and this was reflected in its electrochemical properties, with a linear response of the peak current depending on the reduction extent. The nanocomposite was obtained by in situ photochemical method, and this was confirmed by XRD techniques, Raman and UV-Vis. The micrographs obtained by FEG-SEM showed the presence of PB cubes on the entire surface of the reduced graphene oxide. It is expected that the interaction between the PB and rGO allowing greater electrochemical stability of the material to be tested in H2O2 sensing / Mestrado / Quimica Inorganica / Mestra em Química

In many high dimensional problems, the dependence structure among the variables can be quite complex. An appropriate use of the regularization techniques coupled with other classical statistical methods can often improve estimation and prediction accuracy and facilitate model interpretation, by seeking a parsimonious model representation that involves only the subset of revelent variables. We propose two regularized stochastic regression approaches, for efficiently estimating certain sparse dependence structure in the data. We first consider a multivariate regression setting, in which the large number of responses and predictors may be associated through only a few channels/pathways and each of these associations may only involve a few responses and predictors. We propose a regularized reduced-rank regression approach, in which the model estimation and rank determination are conducted simultaneously and the resulting regularized estimator of the coefficient matrix admits a sparse singular value decomposition (SVD). Secondly, we consider model selection of subset autoregressive moving-average (ARMA) modelling, for which automatic selection methods do not directly apply because the innovation process is latent. We propose to identify the optimal subset ARMA model by fitting a penalized regression, e.g. adaptive Lasso, of the time series on its lags and the lags of the residuals from a long autoregression fitted to the time-series data, where the residuals serve as proxies for the innovations. Computation algorithms and regularization parameter selection methods for both proposed approaches are developed, and their properties are explored both theoretically and by simulation. Under mild regularity conditions, the proposed methods are shown to be selection consistent, asymptotically normal and enjoy the oracle properties. We apply the proposed approaches to several applications across disciplines including cancer genetics, ecology and macroeconomics.

In this era of big data, multivariate time-series (MTS) data are prevalent in diverse domains and often high dimensional. However, there have been limited studies of building a capable classifier with MTS via classical machine learning methods that can deal with the double curse of dimensionality due to high variable dimension and long time series (large sample size). In this thesis, we propose two approaches to address this problem for multiclass classification with high dimensional MTS. Both approaches leverage the dynamics of an MTS captured by non-parametric modeling of its spectral density function. In the first approach, we introduce the reduced-rank spectral classifier (RRSC), which utilizes low-rank estimation and some new discrimination functions. We illustrate the efficacy of the RRSC with both simulations and real applications. For binary classification, we establish the consistency of the RRSC and provide an asymptotic formula for the misclassification error rates, under some regularity conditions. The second approach concerns the development of the random projection ensemble classifier for time series (RPECTS). This method first applies dimension reduction in the time domain via projecting the time-series variables into some low dimensional space, followed by measuring the disparity via some novel base classifier between the data and the candidate generating processes in the projected space. We assess the classification performance of our new approaches by simulations and compare them with some existing methods using real applications. Finally, we elaborate two R packages that implement the aforementioned methods.