Investigation of the pseudo-homogeneous model for ammonia synthesis : use of a compositional approach

Orientador: Maria Teresa Moreira RodriguesDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia QuímicaResumo: O processo de síntese de amônia completou 100 anos em 2013. Esta foi uma das maiores invenções do século XX. Além disso, este processo possui uma elevada gama de temperaturas e pressões, indo de 1 atm a 300 atm e de 200 K até 800 K (na qual a reação pode ocorrer). A produção de amônia acontece em reatores de 150 a 300 atm e de 600 a 810 K, com 30 % de conversão por passe, pois a reação é altamente exotérmica. Mais ainda, a amônia é um gás polar e hidrogênio é um gás quântico nessas condições. Logo, a predição de composição, temperatura e de pressão dentro de reatores de amônia usando modelos apropriados se faz importante. Muitas leis de reação foram propostas. Porém, muitas dessas expressões usavam atividade química sem computar interações entre os componentes. Dessa forma, a modelagem de reatores de amônia utilizando um modelo termodinâmico rigoroso foi proposta neste trabalho. As expressões de Peng e Robinson e de Soave Redlich Kwong foram usadas na taxa de reação proposta por Singh e Saraf. Dois modos de operação foram modelados: adiabático (no qual a reação não troca calor com a vizinhança) e autotérmico (operando não isotermicamente). A atividade catalítica foi ajustada a modelagem por equações de estado. Os dois modelos de reatores foram comparados com dados de planta reais e apresentaram boa concordância. O modelo adiabático apresentou um erro máximo relativo de 1.6 % com a temperatura e de 11.4 % com a conversão. Por outro lado, o modelo autotérmico teve um erro máximo de 2.7 % com a temperatura. Posteriormente uma análise de sensitividade foi realizada em variáveis de entrada de ambos os modelos. A operação adiabática se mostrou mais sensível à variação de pressão e temperatura, enquanto a autotérmica apresentou maiores conversões e melhor remoção de energia. Na parte final, uma estimativa de propriedades na camada limite mássica foi realizada. Os valores de difusão mássica foram pequenos devido à elevada pressão, contudo a resistência externa à transferência de massa se mostrou significativa. Mesmo assim, a maior resistência no reator de síntese de amônia é interna a partícula catalíticaAbstract: Ammonia synthesis process completed 100 years in 2013. It was one of the most important inventions in 20th century. Moreover, the process has a variety of temperatures and pressures, going from 1 atm to 300 atm, and from 200 K to 810 K. The ammonia production takes place in reactors from 150 to 300 atm and 600 to 800 K with 30 % of conversion, because it is highly exothermic. Besides, ammonia is a polar gas and hydrogen is a quantic gas in these conditions. Therefore, the prediction of composition, temperature and pressure inside ammonia converters using appropriate models is important. Furthermore, many reaction rates were proposed for ammonia synthesis. However, most of the expressions used chemical activity without computing compositional interactions between components. So, the modeling of reactors using a rigorous thermodynamic model was proposed. The Peng Robinson and Soave Redlich Kwong expressions were used in Singh and Saraf rate expression. Two modes of operations were modeled: adiabatic (which reaction releases heat without removal) and autothermal (non isothermal operation). The catalyst activity was fitted to EoS modeling. Both models were validated with plant data and they presented good reliability. The adiabatic model presented maximum error of 1.6 % with temperature and 11.4 % with conversion. On the other hand, autothermal model presented maximum error of 2.7 % with temperature. Moreover, the sensitivity analysis of input variables was proposed in both models. The adiabatic operation showed more sensitive to inlet pressure and temperature variations, while the autothermal reactor presented higher conversions and better energy removal. In final part, the estimation of properties in mass boundary layer were made. The values of mass diffusion were low due to high pressure and external resistance was significant. However, when it was compared to internal resistance, the resistance computed by effectiveness factor was dominant in ammonia synthesis reactorMestradoSistemas de Processos Quimicos e InformaticaMestre em Engenharia Química131744/2016-0CNP

Decision Support System for Investment Analysis

The purpose of this thesis lies on selecting and automating a set of Fundamental Analysis indicators and studying related software tools that can help investors understanding market behaviour. The several distinct data-sources, tools and methods will be evaluated using a Decision Making process for Financial Markets. Sometimes there’s not enough data in which we can base the investment decision upon, other times the data lacks quality, while other times, despite having the right data, the problem lies on the process of analyzing the data and then turning that analysis into a concrete decision. Also, since the human decision making process is not well systemized, there are times when both the data and the analysis are well performed, but the results may vary even when confronted with similar data patterns more than once. This is particularly crucial when dealing with fast-paced environments like the Financial Markets. This thesis will therefore study tools for systemizing a Decision Making process based on fundamental analysis indicators over financial markets and will evaluate how such tools help to avoid uncertainty in human decision and to complement lack of data and poor data quality. There are two essential building blocks of such a system: the data set and the model that analyses the data and ultimately, provides information that facilitates the decision making process about a particular investment. Both blocks will be made available in the framework of the research project at GoBusiness Finance.O propósito desta dissertação reside na selecção e sistematização de um conjunto de indicadores financeiros para Análise Fundamental, assim como, o estudo de ferramentas que possam ajudar investidores a terem um melhor entendimento do segmento das acções dos Mercados Financeiros. Por vezes, não existe informação suficiente sobre a qual possamos basear as decisões de investimento, por outrem, existem vezes em que a informação existe, mas a qualidade da mesma não pode ser comprovada. Também acontecem casos em que, apesar de possuirmos a informação adequada, o problema recai no processo de análise da informação e na subsequente tomada de decisão. Para além das questões relacionadas com informação, existe também o facto de o processo de decisão desempenhado pelos humanos não ser bem sistematizado. Assim, podem surgir ocasiões em que as decisões resultantes são distintas, mesmo quando confrontados com padrões de informação e resultados de análise semelhantes. Isto é particularmente importante quando lidamos com ambientes em que as decisões são tomadas de forma tremendamente rápida, como é o exemplo dos mercados financeiros. Com isto, esta tese irá estudar ferramentas para sistematizar o processo de tomar decisões relativas a investimentos nos mercados, com base em princípios análise fundamental. Existem duas componentes essenciais para a construção de um sistema de apoio à decisão: o data set e os modelos de análise ao mesmo. Ambas as componentes serão estudadas e disponibilizadas em âmbito empresarial na Gobusiness Finance

A interação durante as provas operatórias: considerações para a avaliação infantil

The Jean Piaget’s theory classifies child development in stages, according to the cognitive structures established by age and prepares the system of child evaluation – operational tests, known and used in many occasions by occupational therapists. We’ll present relevant results of a critical-reflexive research aimed to analyze the variables during the application of operational conservation tests; seriation; classification and symbolic function in children in pre-operational, formal operational and concrete operational stages. The applied methodologies and materials used were intentionally modified in three stages for each test: traditional material and methodology; diversified material and active manipulation; and personalized material and active methodology. After three months of applications, image recording, completion of research instruments and analyses performed, the main results showed that the active manipulation and the relationship with the diversified materials contributed to answers of higher intellectual maturity of the child, in a considerable number of sessions.A teoria de Jean Piaget classifica o desenvolvimento infantil em estágios, de acordo com as estruturas cognitivas delineadas por idade e elabora o sistema de avaliação infantil - provas operatórias, conhecido e muitas vezes utilizado pelo terapeuta ocupacional. Serão apresentados os resultados relevantes de uma pesquisa que objetivou a análise crítica-reflexiva de variáveis durante a aplicação de provas operatórias de conservação; seriação; classificação e função simbólica em crianças nas fases pré-operatória, operatória e operatória concreta. As metodologias aplicadas e os materiais utilizados foram intencionalmente modificados em três etapas para cada prova: material e metodologia tradicionais, material diversificado e manuseio ativo e material personalizado e metodologia ativa. Após três meses de aplicações, registros imagéticos, instrumentos de pesquisa preenchidos e análises realizadas, temos como principais resultados que o manuseio ativo e a relação com os materiais diversificados contribuíram para respostas de maior maturidade intelectual da criança, em um número considerável de sessões

Participation in programs for seniors: impact on cognition, mood and life satisfaction

Este estudo teve como objetivo investigar a relação entre a participação em programas da terceira idade e os possíveis benefícios para o desempenho cognitivo, humor e satisfação com a vida. Vinte e nove idosos que tinham iniciado participação em quatro centros de convivência foram submetidos a duas avaliações: no início da participação e após seis meses de atividades no grupo. As avaliações foram compostas pelas escalas: Mini-exame do Estado Mental, Lista de Palavras do Consortium to Establish a Registry of Alzheimer Disease, Teste de Fluência Verbal Categoria Animais, Escala de Depressão Geriátrica e Escala de Satisfação com a Vida. Os resultados indicaram que a participação em programas sociais parece gerar benefícios: aumento significativo no resgate das palavras do Consortium to Establish a Registry of Alzheimer Disease e aumento, que se aproximou da significância estatística, da fluência verbal e satisfação com a vida em relação ao envolvimento social. Os efeitos do engajamento da população idosa nesses programas devem ser investigados.The purpose of this research was to investigate the relationship between participation in social activities in senior citizens centers and the potential benefits for cognitive performance, mood and life satisfaction. Twenty-nine seniors, who had recently become members of four senior citizens centers, each completed two evaluations: one prior to participation and the other after six months of group activities. Assessment protocol included the following scales: Mini Mental Status Examination, Word List of the Consortium to Establish a Registry for Alzheimer's Disease, Verbal Fluency Test in the Animals Category, Geriatric Depression Scale, and the Life Satisfaction Scale. Results indicated that participation in social programs can generate benefits: a significant increase was detected in word recall and also an improvement, approaching statistical significance, in word fluency and life satisfaction in terms of social involvement. The impact of the involvement of the elderly in these programs needs to be investigated

Articulating the Shape: Transversal Pedagogical Actions for the Construction of Knowledge on Visual Syntax

This paper emphasizes the development of the ability to articulate the visual / formal syntax as a fundamental way for the consolidation of project thinking among fashion design students. From an exploratory approach, it integrates two research focuses: the first investigates the self-regulation of learning in project teaching; the second addresses methodological strategies for the development of the ability of compositional synthesis. Thus, the study examines practices for Visual Methodology learning in the Bachelor of Fashion Design course at the State University of Londrina, searching for effective contributions in the experimental creative manipulation and decomposition of visual messages. With that aim, a combination of pedagogical actions (assignments) is analyzed, aiming at proving its didactic efficiency. Results confirm the potential of such actions and self-regulated learning strategies as facilitators of the ability to generate expressive concepts and create artifacts in the field of fashion.This paper emphasizes the development of the ability to articulate the visual / formal syntax as a fundamental way for the consolidation of project thinking among fashion design students. From an exploratory approach, it integrates two research focuses: the first investigates the self-regulation of learning in project teaching; the second addresses methodological strategies for the development of the ability of compositional synthesis. Thus, the study examines practices for Visual Methodology learning in the Bachelor of Fashion Design course at the State University of Londrina, searching for effective contributions in the experimental creative manipulation and decomposition of visual messages. With that aim, a combination of pedagogical actions (assignments) is analyzed, aiming at proving its didactic efficiency. Results confirm the potential of such actions and self-regulated learning strategies as facilitators of the ability to generate expressive concepts and create artifacts in the field of fashion

Adaptive Deposition of Difficult Materials

When using a robotic arm, the path that the arm follows is typically unique to the task it completes, but not to the object upon which the task is performed. Additionally, when extruding materials, those materials are typically easy to work with (i.e. smooth and uniform). In this paper, we discuss our three-pronged approach, focusing on the imaging of the cupcake, the robotic arm’s movement about the cupcake, and the extrusion method, to achieve this goal of, simply-speaking, decorating a cupcake. While our results were not optimized or as broad as we’d initially hoped that they would be, we were able to decorate the cupcake in a reliable manner using all three components of the project. We ran into many issues along the way, but did find this to be a relatively successful project with many avenues for continuing research. Future research relating to this project should focus on three main avenues: an optimized image measurement system; increasing the vocabulary of designs for the robotic arm and optimizing them; and creating an automized system for the extruder with a frosting of a better consistency

Joint Analysis of the Discount Factor and Payoff Parameters in Dynamic Discrete Choice Games

Most empirical models of dynamic games assume the discount factor to be known and focus on the estimation of the payoff parameters. However, the discount factor can be identifed when the payoffs satisfy parametric or other nonparametric restrictions. We show when the payoffs take the popular linear-in-parameter specification, the joint identification of the discount factor and payoff parameters can be simplified to a one-dimensional model that is easy to analyze. We also show that switching costs (e.g. entry costs) that often feature in empirical work can be identifed in closed-form, independently of the discount factor and other specification of the payoff function. Our identification strategies are constructive. They lead to easy to compute estimands that are global solutions. Estimating the discount factor permits direct inference on borrowing rate. Our estimates of the switching costs can be used for specification testing. We illustrate with a Monte Carlo study and the dataset from Ryan (2012)

Joint Analysis of the Discount Factor and Payoff Parameters in Dynamic Discrete Choice Games

Most empirical and theoretical econometric studies of dynamic discrete choice models assume the discount factor to be known. We show the knowledge of the discount factor is not necessary to identify parts, or all, of the payoff function. We show the discount factor can be generically identifed jointly with the payoff parameters. It is known the payoff function cannot nonparametrically identified without any a priori restrictions. Our identification of the discount factor is robust to any normalization choice on the payoff parameters. In IO applications normalizations are usually made on switching costs, such as entry costs and scrap values. We also show that switching costs can be nonparametrically identified, in closed-form, independently of the discount factor and other parts of the payoff function. Our identification strategies are constructive. They lead to easy to compute estimands that are global solutions. We illustrate with a Monte Carlo study and the dataset from Ryan (2012