In this thesis we develop new mathematical models, using dynamical systems, to represent localized gene delivery of bone morphogenetic protein 2 into bone marrow-derived mesenchymal stem cells and rat calvarial defects. We examine two approaches, using pDNA or cmRNA treatments, respectively, towards the production of calcium deposition and bone regeneration in in vitro and in vivo experiments. We first review the relevant scientific literature and survey existing mathematical representations for similar treatment approaches. We then motivate and develop our new models and determine model parameters from literature, heuristic approaches, and estimation using sparse data. We next conduct a qualitative analysis using dynamical systems theory. Due to the nature of the parameter estimation, it was important that we obtain local and global sensitivity analyses of model outputs to changes in model inputs. Finally we compared results from different treatment protocols. Our model suggests that cmRNA treatments may perform better than pDNA treatments towards bone fracture healing. This work is intended to be a foundation for predictive models of non-viral local gene delivery systems.

Orientador: Samuel Conceição de Oliveira / Resumo: A determinação da estratégia de controle adequada para bioprocessos batelada e batelada alimentada é uma questão prática importante devido ao alto valor agregado de alguns bioprodutos. Desde que é altamente desejável otimizar a produção de bioprodutos, vários métodos têm sido propostos para esse objetivo. Uma vez dispondo de um modelo matemático adequado para o bioprocesso, o problema de otimização pode ser formulado no âmbito do princípio do máximo de Pontryagin e da teoria de controle ótimo para determinar a melhor trajetória de controle para certas variáveis manipuladas, como temperatura, pH e taxa de alimentação do substrato. Neste estudo, duas aplicações dessas técnicas baseadas em modelos matemáticos para otimizar e controlar bioprocessos de produção de antibióticos são revisadas e novos aspectos são enfatizados. Os casos analisados incluem a otimização da taxa de alimentação de substrato em um reator batelada alimentada e da temperatura em um reator batelada durante fermentações penicilínicas. Os principais resultados obtidos neste estudo foram: (i) a constatação de que métodos numéricos simples (Runge-Kutta, Newton-Raphson) podem ser aplicados para resolver satisfatoriamente os problemas de valor no contorno propostos; (ii) a demonstração de que a operação não isotérmica é mais produtiva em antibiótico do que a operação sob temperatura constante; (iii) a necessidade de adoção de um modelo matemático apropriado para o bioprocesso visando à resolução do problema de cont... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre

Orientador: Helenice de Oliveira Florentino Silva / Banca: Sonia Cristina Poltroniere Silva / Banca: Maura Seiko Tsutsui Esperancini / Resumo: A cana-de-açúcar é considerada uma das mais importantes culturas dentro do agronegócio brasileiro, sua utilização é destinada principalmente para produção de açúcar, etanol e bioeletricidade, além de outros importantes produtos. Sob uma ótica econômica, a cultura da cana-de-açúcar, tem relevância na geração de empregos de renda e de divisas para o país produtor. Devido à importância desta cultura, houve uma grande expansão deste setor, tornando o planejamento de processos sucroenergéticos muito complexo. Neste contexto, gestores e pesquisadores dos setores privado e público estão juntando esforços para obter estratégias que facilitem a gestão destas empresas, respeitando os fatores políticos, ambientais, sociais e econômicos. Muitas das vezes, estas estratégias exigem o emprego de técnicas matemáticas e computacionais para subsidiar tomadas de decisão mais assertivas. Assim, o objetivo desse trabalho é propor uma metodologia envolvendo técnicas matemáticas que auxiliem na minimização do tempo de duração da colheita, considerando a otimização do tempo de manobras dos veículos de transbordo na cabeceira do talhão, visto que esta é a operação que mais demanda tempo durante o processo de corte da cana. A metodologia proposta considera duas etapas, em que na primeira é aplicado um modelo matemático para minimização do número de manobras a serem realizadas pelo veículo na área de colheita e na segunda etapa é sugerido um procedimento para realização da manobra, o qual permite que e... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Sugarcane is considered one of the major crops in Brazilian agribusiness as it is utilized mainly for the production of sugar, ethanol and bioelectricity besides other important products. Under an economic perspective, sugarcane cultivation has been relevant to creation of jobs, income, and foreign exchange for the producing country. Due to the importance of this crop, there has been a great expansion of this sector which has resulted in very complex planning of sugar-energy processes. Therefore, managers and researchers from the public and private sectors have been working together in order to develop strategies that make the management of these companies easier while respecting political, environmental, social and economic factors. Mostly, these strategies demand the use of mathematical and computational models to subsidize more assertive decision making. Thus, this study aimed to propose a methodology involving mathematical models that help minimize the harvest time, considering time optimization of transshipment maneuvers at the plot since this is the longest operation in the sugarcane cutting process. The proposed methodology presents two phases: first, a mathematical model is applied to minimize the number of maneuvers to be done by the truck in the harvesting area, and then a maneuver procedure to shorten the average maneuvering time is presented. By minimizing the maneuvering time of agricultural machinery, this study will consequently contribute to the reduction of t... (Complete abstract click electronic access below) / Mestre

Orientador: Renata Zotin Gomes de Oliveira / Resumo: Neste trabalho apresentamos um estudo introdutório à Teoria de Conjuntos Fuzzy e Lógica Fuzzy, mostrando o seu potencial de aplicação através do aperfeiçoamento do cálculo da estimativa do tempo de vida de um transformador de energia elétrica, informação de grande importância para a equipe de qualidade de uma empresa conseguir prever o melhor momento de manutenção. Foi desenvolvido um sistema computacional que consulta uma base de dados já existente e aplica o cálculo do tempo de vida utilizando três métodos diferentes, permitindo ao usuário comparar e selecionar o resultado mais próximo ao real, com base em fatores externos. Como energia elétrica é um tema amplo que aparece em diversos componentes curriculares, facilitando a construção de projetos interdisciplinares, apresentamos uma proposta de projeto onde será criada uma maquete de uma turbina hidrelétrica utilizando conceitos da construção geométrica e a modelagem matemática da tensão gerada por esta turbina, em função da altura. A proposta de projeto foi aplicada no 8◦ ano do Ensino Fundamental e os resultados estão presentes no trabalho. / Abstract: In this work we present an introductory study of Fuzzy Sets Theory and Fuzzy Logic, showing its potential for application through the improvement of the calculation of the life span estimation of an electrical power transformer, information of great importance for the company's quality team to predict the best moment of maintenance. It was developed a computational system that consults the existing database and applies the calculation of the life span using three di erent methods, allowing the user to compare and select the result closest to the actual based on external factors. Since electric energy is a broad theme that appears in several curricular components, facilitating the construction of interdisciplinary projects, we present a project proposal where a model of a hydroelectric turbine will be created using concepts of geometric construction and the mathematical modelling of the tension generated by this turbine, as a function of height. The project proposal was applied in the 8◦ year of elementary school and the results are present at work. / Mestre

"December, 2004." / Bibliography: leaves 229-251. / xvi, 265 leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, School of Agriculture and Wine, Disciplines of Animal Science and Biometrics SA, 2005?

This study presents an optimization approach to heat exchanger network synthesis (HENS). HENs are widely used in industry and bring several fluid streams into their desired temperatures by using available heat in the process for efficient usage of energy. Our aim is to provide a network design coupled with a detailed equipment design for heat exchangers. The suggested approach involves discretization of temperatures based on heat load equalities and reformulation as a shortest-path problem, rather than dealing with a nonlinear model and a previously structured HEN, which are common methods in the literature. We generate a shortest path network whose every node corresponds to a heat exchanger alternative and each path represents a HEN design alternative. A mixed-integer nonlinear programming model is solved to design each exchanger alternative in detail, considering all thermo-physical and transport properties of streams at their temperatures and pressures. Our approach has modeling flexibility and successfully finds the required number of heat exchangers and their connections. In addition, one can control the solution quality by deciding on the heat load steps between stream inlet and outlets. Several HEN examples from the literature are solved to assess the performance of our approach and comparable results are obtained.

Although an increasing number of research studies in mathematics education have begun focusing their efforts on mathematical modeling as a need for change to convey mathematical ideas beyond schools, there is not enough information about the nature of the teacher knowledge for effective use of modeling in mathematics teaching and how this knowledge evolves. The goal of this study is to investigate teachers&rsquo / evolving knowledge when they engage in professional development activities based on lesson study cycle from modeling perspective. Professional development program of this study included a cyclical process. Lasting a month, each cycle consisted of meeting before the implementation of the model eliciting activity, implementation of the activity and meeting after the implementation. The study took five months and was conducted in two public schools. The participants were four in-service mathematics teachers where two teachers were selected from each school by purposive sampling. The study was designed as case study. Data analyses were conducted during and after data collection and with two approaches as with-in case and cross-case analysis. As the professional development activities created learning environments for the teachers to develop their models for teaching mathematics from a modeling perspective, the results of this study showed that the professional development program used in the study had a positive effect on teachers&rsquo / evolving pedagogical content knowledge and pedagogical knowledge based on the theoretical and empirical backgrounds in the literature. Besides, implications, suggestions for professional development, for teachers and for further research are provided.

Molten carbonate fuel cells (MCFCs) have become an attractive emerging technology for stationary co-generation of heat and power. From a technical perspective, dynamic operation has a significant effect on the fuel cell life cycle and, hence, economic viability of the device. The scope of this thesis is to present an improved understanding of the system behaviour at transient operation that can be used to design a more robust control system in order to overcome the cost and the operating lifetime issues. Hence, a comprehensive multi-component multidimensional transient mathematical model is developed based on the conservation laws of mass, momentum, species, energy and electric charges coupled through the reaction kinetics. In essence, this model is a set of partial differential equations that are discretized and solved using the finite-volume based commercial software, ANSYS FLUENT 12.0.1. The model is validated with two sets of experimental results, available in open literature, and good agreements are obtained. The validated model is further engaged in an extensive study. First, the MCFC behaviour at high current densities or oxidant utilization, when the mass transfer becomes dominant, is investigated using peroxide and superoxide reaction mechanisms. In brief, both mechanisms predicted the linear region of the polarization curve accurately. However, none of these mechanisms showed a downward bent in the polarization curve. A positive exponent for the carbon-dioxide mole fraction is probably essential in obtaining the downward bent (“knee”) at high current densities which is in contrast to what has been reported in the literature to date. Next, a sinusoidal impedance approach is used to examine the dynamic response of the unit cell to inlet perturbations at various impedance frequencies. This analysis is further used to determine the phase shifts and time scales of the major dynamic processes within the fuel cell. Furthermore, numerical simulation is utilized in order to investigate the underlying electrochemical and transport phenomena without performing costly experiments. Results showed that the electrochemical reactions and the charge transport process occur under a millisecond. The mass transport process showed a comparatively larger time scale. The energy transport process is the slowest process in the cell and takes about an hour to reach its steady state condition. Furthermore, the developed mathematical model is utilized as a predictive tool to provide a three-dimensional demonstration of the transient physical and chemical processes at system startiv up. The local distribution of field variables and quantities are presented. The results show that increasing the electrode thickness provides a higher reaction rate, but may lead to larger ohmic loss which is not desirable. The reversible heat generation and consumption mechanisms of the cathode and anode are dominant in the first 10 s while the heat conduction from the solid materials to the gas phase is not considerable. The activation and ohmic heating have the same impact within the anode and cathode because of their similar electric conductivity and voltage loss. Increasing the thermal conductivity of the cathode material will facilitate the process of heat transport throughout the cell. This can also be accomplished by lowering the effects of heat conduction by means of a cathode material with a smaller thickness. In addition, a thermodynamic model is utilized to examine energy efficiency, exergy efficiency and entropy generation of a MCFC. By changing the operating temperature from 883 K to 963 K, the energy efficiency of the unit cell varies from 42.8 % to 50.5 % while the exergy efficiency remains in the range of 26.8% to 36.3%. Both efficiencies initially rise at lower current densities up to the point that they attain their maximum values and ultimately decrease with the increase of current density. With the increase of pressure, both energy and exergy efficiencies of the cell increase. An increase in this anode/cathode flow ratio lessens the energy and exergy efficiencies of the unit cell. Higher operating pressure and temperature decrease the unit cell entropy generation. / UOIT

Controlling fates of stem and progenitor cells is one of the central goals of regenerative medicine. However, conventional cell enumeration methods are unable to distinguish between the effects of cell death, proliferation, and differentiation through molecular interventions on the output of specific cell types. We have devised a strategy to simultaneously obtain proliferation and death rates in cultures of highly purified erythroid progenitors. The approach is based on combining cell-surface marker analysis, cell-division tracking and 7-amino-actinomycin-D staining to monitor cell death. A compartment model of cell proliferation was developed to evaluate cell generation-specific length of cell-division, rates of entry into division, and cell death, from the experimental cell-division tracking data obtained following stimulation with erythropoietin (EPO) and Stem cell factor (SCF). The results indicated that EPO and SCF, either as single factor or in combination, differentially affect the rates of differentiation, length of cell-division and rates of death.

Controlling fates of stem and progenitor cells is one of the central goals of regenerative medicine. However, conventional cell enumeration methods are unable to distinguish between the effects of cell death, proliferation, and differentiation through molecular interventions on the output of specific cell types. We have devised a strategy to simultaneously obtain proliferation and death rates in cultures of highly purified erythroid progenitors. The approach is based on combining cell-surface marker analysis, cell-division tracking and 7-amino-actinomycin-D staining to monitor cell death. A compartment model of cell proliferation was developed to evaluate cell generation-specific length of cell-division, rates of entry into division, and cell death, from the experimental cell-division tracking data obtained following stimulation with erythropoietin (EPO) and Stem cell factor (SCF). The results indicated that EPO and SCF, either as single factor or in combination, differentially affect the rates of differentiation, length of cell-division and rates of death.