The following EngD thesis presents research on the potential for short term deployment of carbon dioxide utilisation technologies within the context of the European steel industry, in collaboration with Tata Steel Europe. The aim of the project was to identify options for short term utilisation of CO2 directly from steelmaking process exhausts and then evaluate them in terms of their technical feasibility, CO2 reduction potential and economic sustainability. An initial review of steel production processes and CDU routes resulted in the selection of two potentially promising processes for further investigation; production of precipitated calcium carbonate (PCC) from steelmaking wastes, and combined biomass production and steelmaking wastewater remediation using microalgae. Each technology was investigated experimentally to determine its technical feasibility, and then via a techno-economic evaluation in order to estimate the scale of potential CO2 mitigation and economic viability. Although both technologies were deemed to be technically feasible, when techno-economic evaluations were performed it became clear that neither technology is likely to be able to achieve significant CO2 emissions reductions (reduction is limited to less than 1% of typical integrated site emissions). Despite this, economic estimates for a scaled up PCC production process were promising; a moderate payback on capital expenditure of around 5.51 years was estimated under baseline conditions, with a significant additional revenue potential if the process were credited under the European Union Emissions Trading Scheme. In contrast, the microalgae based process was found to be highly uneconomical when using technology which is currently available at a commercial scale, and the CO2 mitigation potential was determined to be limited by the indirect CO2 emissions from very high electricity demands as the process is scaled up.

Amine functionalised silica adsorbents are promising materials for post combustion carbon capture. They exhibit high CO2 equilibrium adsorption capacities and selectively adsorb CO2 in the presence of water. A practical method of regenerating these materials in fossil fuel power stations is to utilise steam regeneration. There is a lack of understanding of the long term stability of amine functionalised silica in the presence of steam. This thesis explored the deactivation mechanism of impregnated and covalently tethered amine adsorbents under steam regeneration and humid adsorption conditions. The adsorbents were characterised using organic analysis and nitrogen sorption before and after aging. The effect of steam regeneration aging led to a significant decrease in the CO2 adsorption uptakes of the adsorbents. Impregnated amine adsorbents were deactivated by leaching of the impregnated amine component from the largest pores of the support. Steam aging also led to diminished amine accessibility caused by amine polymer agglomerating within pores below 8 nm. To address this issue of instability in the presence of steam amine impregnated silica adsorbents were post functionalised with organosilanes. Under certain conditions this silane functionalisation was shown to selectivity occur at the exterior and pore mouths of the adsorbent. The presence of silane coatings preserved the CO2 adsorption capacities of the adsorbents after aging. A compromise exists between adsorbent stability and CO2 uptake behaviour as silane functionalisation led to a reduction in the CO2 uptake capacity. Post functionalisation of amine impregnated silica with hydrophobic silanes limits the intrusion of water within the pores of the adsorbent. This reduction in water intrusion limits the rate of solubilisation of the amine polymer, thus preventing leaching. The impregnation of amine polymers onto porous silica supports typically leads to agglomerations and significant pore blocking. This limits the rate of adsorption and uptake capacity of the adsorbents. The introduction of aminesurfactant mixtures into the adsorbent was found to increase accessibility of the adsorption sites leading to enhanced rates of adsorption and CO2 equilibrium uptakes. The addition of surfactants also yielded a reduction in the regeneration requirements of the adsorbents, by the formation of favourable thin films of amine within the pores of the adsorbent.

The ability of proteins to engage in nuclear-cytoplasmic shuttling is required for their proper function. The nuclear export of the von Hippel Lindau (VHL) tumour suppressor protein is necessary for the proteasomal degradation of the hypoxia inducible factor alpha (HIFα). Studies have identified that the nuclear export of VHL and other proteins encoding a Transcription-Dependent Nuclear Export Motif (TD-NEM) is independent of the classical CRM1 nuclear export pathway but requires ongoing transcription. Furthermore, the eukaryotic elongation factor 1 alpha (eEF1A) was identified as a mandatory component of the TD-NEM-mediated nuclear export machinery. In this study, we have uncovered the ability of eEF1A to mediate the nuclear export of proteins by accessing the nuclear compartment in its inactive, GDP-bound form. Although previously thought of as a strictly cytoplasmic protein, work conducted in this thesis has shown that eEF1A is a nuclear-cytoplasmic shuttling protein and this ability is required for the effective export of proteins encoding a TD-NEM.

No description available.

Nesta dissertação, apresentamos uma aplicação simples de RMN de 1H no domínio do tempo (TD-NMR) de baixo campo para caracterização de dinâmica molecular variando do regime intermediário ao rápido. O método se baseia no filtro dipolar seguido da aplicação do Mixed Magic Sandwich Echo(MSE), o qual denominamos DF-MSE. O filtro dipolar suprime os sinais oriundo de segmentos com mobilidade abaixo de kHz, de modo que somente segmentos móveis sejam detectados. Assim, a dependência com a temperatura da intensidade do sinal mostra diretamente a temperatura em que movimentos moleculares ocorrem ao atingirem taxas maiores que kHz. Para que não ocorra variação da intensidade com a temperatura, mas somente pelos movimentos moleculares, os sinais são normalizados por uma intensidade de referência obtida pela aquisição de DF-MSE sem aplicação do filtro dipolar. A intensidade normalizada DF-MSE pode ser descrita adequadamente por uma expressão analítica baseada na aproximação de Anderson-Weiss, de forma a permitir que parâmetros de ativação de movimentos sejam avaliados. Ademais, também propomos um método baseado na diferença entre sinais DF-MSE normalizados adquiridos com tempos de filtro distintos, permitindo assim quantificar a largura da ditribuição de tempos de correlação de uma forma independente. A aplicação geral foi testada de forma bem sucedida em polímeros monofásicos e multifásicos. De fato, o método apresentado é um prosseguimento da análise feita pelo MSE já presente na literatura, porém sondando movimentos mais rápidos e com uma forma aprimorada para avaliação de heterogeneidades de movimento. / In this dissertation, we present a simple NMR approach for characterizing intermediate to fast regime molecular dynamics using 1H time-domain NMR (TD-NMR) at low magnetic field. The method is based on a dipolar filter followed by a Mixed Magic Sandwich Echo and FID acquisition, which is symbolized DF-MSE. The dipolar filter suppresses the signals of segments presenting sub kHz mobility, so only signals from mobile segments are detected. Thus, the temperature dependence of the signal intensities directly evidences the onset of molecular motions with rates higher than kHz. In order to avoid temperature variation of the signal intensities other than that due to motions, the signals are normalized by a reference intensity obtained in a DF-MSE acquisition without the dipolar filter. The normalized DF-MSE intensity can be well described by an analytical function based on the Anderson-Weiss approach, so the activation parameters of the motion can be evaluated. Furthermore, we also propose a method based on the difference between normalized DF-MSE signals acquired with different dipolar filter times, which provide evaluation of the width of the distribution of correlation times in an independent fashion. The general approach was successfully tested in single and multiphase polymer systems. Indeed, the presented method is a follow up of the MSE analysis previously reported, but probing faster motions and with an improved way of evaluating the motion heterogeneities.

Le VRP permet de modéliser la problématique du TMV. Pour autant dans sa version la plus simpliste il ne peut convenir aux nouvelles contraintes qui renforcent la complexité de l’environnement urbain tel que la congestion. Raison pour laquelle ce travail se positionne en premier sur un TDVRP (Time-Dependent-Vehicle-Routing-Problem) dans le but de représenter au mieux le contexte urbain actuel. La résolution de ces deux problèmes est efficace, entraînant une réduction du nombre de véhicules supplémentaires nécessaires en raison des retards de congestion peuvent être éliminés. Mais cette solution n’est pas sans conséquence pour les clients finaux puisque son but est d’éviter le passage aux heures de pointes et cela peut engendrer des retards de livraison. Pour cette raison nous voulons proposer une nouvelle solution qui permet de résoudre le problème du chemin le plus court et en intégrant la dépendance au temps (TDVRP). Cette solution se repose sur une meilleure exploitation des véhicules, en premier lieu, pour réduire le nombre de véhicule sur la route. Ce problème s’appelle MT-VRP (Multi-Trip VRP) qui a été évoqué en 2007 par (Azi, et al. 2007). Dans un deuxième temps nous voulons proposer un MT VRP qui utilise différents types de véhicule en termes de capacité de chargement. Dans cette optique vient notre travail qui propose une nouvelle solution de MTTDVRP (TW avec fenêtres de temps) en testant une nouvelle solution en utilisant un véhicule léger de faible capacité de chargement (type tricycle) dans un but de réduire les nuisances liés au TMV. / The VRP makes it possible to model the problem of TMV. However, in its most simplistic version it cannot be adapted to the new constraints which reinforce the complexity of the urban environment such as congestion. This is why this work is placed first on a TDVRP (Time-dependent-Vehicle-Routing-Problem) in order to best represent the current urban context. The resolution of these two problems is effective; resulting in a reduction in the number of additional vehicles needed due to congestion delays can be eliminated. But this solution is not without consequences for end customers since its goal is to avoid the switch to peak hours and this can lead to delivery delays. For this reason we want to propose a new solution that solves the problem of the shortest path and integrating time dependency (TDVRP). This solution relies on better operation of vehicles, in the first place, to reduce the number of vehicles on the road. This problem is called MT-VRP (Multi-Trip VRP) which was raised in 2007 by (Azi, et al. 2007). In a second step we want to propose a MT VRP that uses different types of vehicle in terms of loading capacity. In this perspective comes our work that proposes a new solution of MTTDVRP (TW with time windows) by testing a new solution using a light vehicle of low load capacity (tricycle type) in order to reduce the nuisance associated with TMV.

Nesta dissertação, apresentamos uma aplicação simples de RMN de 1H no domínio do tempo (TD-NMR) de baixo campo para caracterização de dinâmica molecular variando do regime intermediário ao rápido. O método se baseia no filtro dipolar seguido da aplicação do Mixed Magic Sandwich Echo(MSE), o qual denominamos DF-MSE. O filtro dipolar suprime os sinais oriundo de segmentos com mobilidade abaixo de kHz, de modo que somente segmentos móveis sejam detectados. Assim, a dependência com a temperatura da intensidade do sinal mostra diretamente a temperatura em que movimentos moleculares ocorrem ao atingirem taxas maiores que kHz. Para que não ocorra variação da intensidade com a temperatura, mas somente pelos movimentos moleculares, os sinais são normalizados por uma intensidade de referência obtida pela aquisição de DF-MSE sem aplicação do filtro dipolar. A intensidade normalizada DF-MSE pode ser descrita adequadamente por uma expressão analítica baseada na aproximação de Anderson-Weiss, de forma a permitir que parâmetros de ativação de movimentos sejam avaliados. Ademais, também propomos um método baseado na diferença entre sinais DF-MSE normalizados adquiridos com tempos de filtro distintos, permitindo assim quantificar a largura da ditribuição de tempos de correlação de uma forma independente. A aplicação geral foi testada de forma bem sucedida em polímeros monofásicos e multifásicos. De fato, o método apresentado é um prosseguimento da análise feita pelo MSE já presente na literatura, porém sondando movimentos mais rápidos e com uma forma aprimorada para avaliação de heterogeneidades de movimento. / In this dissertation, we present a simple NMR approach for characterizing intermediate to fast regime molecular dynamics using 1H time-domain NMR (TD-NMR) at low magnetic field. The method is based on a dipolar filter followed by a Mixed Magic Sandwich Echo and FID acquisition, which is symbolized DF-MSE. The dipolar filter suppresses the signals of segments presenting sub kHz mobility, so only signals from mobile segments are detected. Thus, the temperature dependence of the signal intensities directly evidences the onset of molecular motions with rates higher than kHz. In order to avoid temperature variation of the signal intensities other than that due to motions, the signals are normalized by a reference intensity obtained in a DF-MSE acquisition without the dipolar filter. The normalized DF-MSE intensity can be well described by an analytical function based on the Anderson-Weiss approach, so the activation parameters of the motion can be evaluated. Furthermore, we also propose a method based on the difference between normalized DF-MSE signals acquired with different dipolar filter times, which provide evaluation of the width of the distribution of correlation times in an independent fashion. The general approach was successfully tested in single and multiphase polymer systems. Indeed, the presented method is a follow up of the MSE analysis previously reported, but probing faster motions and with an improved way of evaluating the motion heterogeneities.

Orientador: Rogerio Custodio / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-11T20:32:26Z (GMT). No. of bitstreams: 1 Souza_KelyFerreirade_M.pdf: 2708513 bytes, checksum: 018efeaf228676a57ca3b884dc55ca80 (MD5) Previous issue date: 2008 / Resumo: Piroxicam é um fármaco com atividade analgésica, antiinflamatória e antipirética de uso muito difundido. Apresenta algumas reações adversas, dentre as quais a possibilidade de foto-sensibilidade cutânea após exposição do paciente à radiação solar. Por este motivo, o fármaco tem sido alvo de inúmeros estudos, mas até os dias atuais não se conhece o mecanismo envolvido na foto-sensibilidade. Com o objetivo de buscar maiores informações sobre o fármaco, o presente trabalho partiu de estudos preliminares tanto da forma ceto quanto da enólica, através do método AM1. Os resultados, em conjunto com dados experimentais, apontaram para o Piroxicam enol como principal tautômero envolvido nos mecanismos de foto-toxicidade. Construiu-se então uma superfície de potencial para o Piroxicam enol, agora com o método DFT/B3LYP/CEP-31G(d,p). Estudaram-se as barreiras de interconversão entre os confôrmeros mais estáveis através do método QST2. Calculou-se o espectro eletrônico destas espécies empregando o método TD-DFT/B3LYP/CEP-31G(d,p) utilizando-se o modelo PCM para inclusão do efeito de solvente. De posse do confôrmero de maior interesse, partiu-se para o estudo de uma proposta de mecanismo obtida da literatura para a reação entre o Piroxicam enol e a molécula de oxigênio no primeiro estado excitado singlete. Partindo-se da otimização em DFT/B3LYP/CEP-31G(d,p) das geometrias das espécies envolvidas no mecanismo, realizou-se a busca por estados de transição entre as mesmas através dos métodos QST2 e QST3. Estruturas de transição entre os caminhos testados foram obtidas, mostrando a possibilidade do mecanismo ocorrer. Os resultados do trabalho apontam, ainda, para um dos confôrmeros como o mais provável de se envolver em foto-reações / Abstract: Piroxicam is a widely used drug with analgesic, antiinflamatory and antipiretic properties. Undesirable side effects are observed in some patients, among which the photosensitivity skin after exposure to solar radiation. For that reason the drug has been widely studied, but until the present days the mechanism involved in the photosensitivity is still unknown. Looking for more information about the drug, preliminary studies were carried out on two tautomers of Piroxicam ¿ ceto and enol structures, using the AM1 method. The calculated and experimental data suggest that Piroxicam Enol is the main tautomer involved in the phototoxicity mechanisms. A new potential surface, now using the DFT/B3LYP/CEP- 31G(d,p) method, was calculated. The interconversion barriers were studied using the QST2 method. The electronic spectrum was calculated with the TD-DFT/B3LYP/CEP- 31G(d,p) method and the solvent effect was investigated applying the PCM model. The predominant conformer was studied in combination with the singlet excited oxygen molecule and a mechanism proposed in the literature was investigated. From the optimized geometries of the species involved in this mechanism, the transition states between them were studied using the QST2 and QST3 methods indicating a feasible reaction path. The results also show one of the conformers as the most important agent responsible by the photochemical sensitivity / Mestrado / Físico-Química / Mestre em Química

As novas tecnologias de informação e comunicação (TCIs) atreladas a projetos de educação a distância (EAD) expandem a possibilidade de acesso a programas de treinamento, formação e qualificação profissionais ofertados. Todavia, tais progressos tecnológicos cada vez mais disseminados pelo campo da EAD, não foram capazes de evitar a ocorrência da evasão. Nesse sentido, fazem-se necessários modelos de avaliação específicos para ações a distância, capazes de identificar os fatores relacionados tanto à permanência estudantil em cursos de tal natureza, bem como à desistência dos mesmos. O presente projeto de pesquisa objetivou propor e testar um modelo de avaliação de ações educacionais ofertadas a distância, buscando identificar variáveis preditoras de elementos ligados à evasão e persistência acadêmica (contexto de estudo, desenho do treinamento e o próprio estudante) relacionadas às características da clientela (dados sociodemográficos e estratégias de aprendizagem). As universidades partícipes ofertam cursos superiores em EAD. Foram aplicados virtualmente os questionários de Estratégias de aprendizagem e Fatores relacionados à evasão e à persistência em EAD, sendo que os mesmos sofreram alterações a fim de se ajustarem às particularidades dos contextos de ensino superior (validação semântica e/ou por juízes). Foram realizadas análises exploratórias fatoriais (Principal Components e Principal Axis Factoring) e de consistência interna (Alpha de Cronbach). Os resultados indicaram que todas as escalas são estatisticamente válidas e confiáveis. A fim de cumprir o objetivo de testagem do modelo proposto, foi realizada a análise de regressão múltipla padrão. As variáveis sociodemográficas denominadas composição familiar e estado civil e as estratégias de aprendizagem explicaram os fatores ligados à evasão e à permanência em EAD. Tais resultados indicam para a relevância do uso de estratégias que promovam o autogerenciamento dos processos de ensino e aprendizagem, a autorregulação da motivação/ansiedade e a busca por ajuda interpessoal na consecução de resultados acadêmicos positivos, beneficiando o desempenho dos discentes que estudam a distância. Mais estudos são fundamentais a fim de sistematizar os conhecimentos acerca das variáveis que podem contribuir para a permanência ou saída do aluno em ações instrucionais na modalidade EAD. / The new information and communication technologies linked to distance learning (DL) expand the possibility of access to training programs, professional training and qualifications offered. However, these technological advances increasingly widespread across the field of distance education, were unable to prevent the occurrence of dropout. In this sense, they are necessary assessment models for specific actions at a distance, able to identify the real factors behind the high dropout rates of courses, observed in various educational settings in different countries. This research project aimed to propose and test a model for evaluating educational activities offered in the distance, trying to identify predictors of dropout related to customer characteristics (sociodemographic data, use of electronic tools, learning strategies) and factors related to dropout and persistence in DL (context of study, training and design student himself). The university offers undergraduate courses in participant DL. It was applied virtually the questionnaires Learning strategies and Factors related to dropout and persistence in DL, and that they have changed to fit the peculiarities of higher education contexts (semantic validation and/or judges). Factorial exploratory analyzes (Principal Components and Principal Axis Factoring) and internal consistency (Cronbach\'s alpha) were performed. The results indicate that all scales are statistically valid and reliable. In order to fulfill the objective of testing the proposed model, a standard multiple regression analysis was performed. The sociodemographic variables named family composition and marital status and learning strategies explain the factors related to dropout and residence in distance education. These results indicate the relevance of the use of strategies that promote self-management processes of teaching and learning, self-regulation of motivation/interpersonal anxiety and search for help in achieving positive academic outcomes, benefiting the performance of students who study at a distance. More studies are essential in order to systematize the knowledge about the variables that may contribute to or departure of the student instructional actions in DL mode.

As novas tecnologias de informação e comunicação (TCIs) atreladas a projetos de educação a distância (EAD) expandem a possibilidade de acesso a programas de treinamento, formação e qualificação profissionais ofertados. Todavia, tais progressos tecnológicos cada vez mais disseminados pelo campo da EAD, não foram capazes de evitar a ocorrência da evasão. Nesse sentido, fazem-se necessários modelos de avaliação específicos para ações a distância, capazes de identificar os fatores relacionados tanto à permanência estudantil em cursos de tal natureza, bem como à desistência dos mesmos. O presente projeto de pesquisa objetivou propor e testar um modelo de avaliação de ações educacionais ofertadas a distância, buscando identificar variáveis preditoras de elementos ligados à evasão e persistência acadêmica (contexto de estudo, desenho do treinamento e o próprio estudante) relacionadas às características da clientela (dados sociodemográficos e estratégias de aprendizagem). As universidades partícipes ofertam cursos superiores em EAD. Foram aplicados virtualmente os questionários de Estratégias de aprendizagem e Fatores relacionados à evasão e à persistência em EAD, sendo que os mesmos sofreram alterações a fim de se ajustarem às particularidades dos contextos de ensino superior (validação semântica e/ou por juízes). Foram realizadas análises exploratórias fatoriais (Principal Components e Principal Axis Factoring) e de consistência interna (Alpha de Cronbach). Os resultados indicaram que todas as escalas são estatisticamente válidas e confiáveis. A fim de cumprir o objetivo de testagem do modelo proposto, foi realizada a análise de regressão múltipla padrão. As variáveis sociodemográficas denominadas composição familiar e estado civil e as estratégias de aprendizagem explicaram os fatores ligados à evasão e à permanência em EAD. Tais resultados indicam para a relevância do uso de estratégias que promovam o autogerenciamento dos processos de ensino e aprendizagem, a autorregulação da motivação/ansiedade e a busca por ajuda interpessoal na consecução de resultados acadêmicos positivos, beneficiando o desempenho dos discentes que estudam a distância. Mais estudos são fundamentais a fim de sistematizar os conhecimentos acerca das variáveis que podem contribuir para a permanência ou saída do aluno em ações instrucionais na modalidade EAD. / The new information and communication technologies linked to distance learning (DL) expand the possibility of access to training programs, professional training and qualifications offered. However, these technological advances increasingly widespread across the field of distance education, were unable to prevent the occurrence of dropout. In this sense, they are necessary assessment models for specific actions at a distance, able to identify the real factors behind the high dropout rates of courses, observed in various educational settings in different countries. This research project aimed to propose and test a model for evaluating educational activities offered in the distance, trying to identify predictors of dropout related to customer characteristics (sociodemographic data, use of electronic tools, learning strategies) and factors related to dropout and persistence in DL (context of study, training and design student himself). The university offers undergraduate courses in participant DL. It was applied virtually the questionnaires Learning strategies and Factors related to dropout and persistence in DL, and that they have changed to fit the peculiarities of higher education contexts (semantic validation and/or judges). Factorial exploratory analyzes (Principal Components and Principal Axis Factoring) and internal consistency (Cronbach\'s alpha) were performed. The results indicate that all scales are statistically valid and reliable. In order to fulfill the objective of testing the proposed model, a standard multiple regression analysis was performed. The sociodemographic variables named family composition and marital status and learning strategies explain the factors related to dropout and residence in distance education. These results indicate the relevance of the use of strategies that promote self-management processes of teaching and learning, self-regulation of motivation/interpersonal anxiety and search for help in achieving positive academic outcomes, benefiting the performance of students who study at a distance. More studies are essential in order to systematize the knowledge about the variables that may contribute to or departure of the student instructional actions in DL mode.