Dissertations / Theses on the topic 'Pre-equilibrium'

A solution concept maps strategic games into strategy predictions. Nash equilibrium is the most widely used solution concept in game theory. Three main explanations have been used to argue why players should end up playing Nash equilibrium: 1) introspective reasoning, 2) communication 3) learning. Careful study of these has shown that the case for the Nash equilibrium is not entirely unambiguous. In this thesis, we conclude with new insights into why Nash equilibrium may be too restrictive a prediction in the context of pre-play communication and learning. Experiments suggest that communication increases the contribution to public goods. There is also evidence that, when contemplating a lie, people trade off their private benefit from the lie with the harm it inflicts on others. In the first chapter, we develop a theory of bilateral pre-play negotiation that assumes the latter and implies the former. We show that a preference for not lying enables non-Nash outcomes. In symmetric games, pre-play negotiations crucially depend on whether actions are strategic complements or substitutes. With strategic substitutes commitment power tends to decrease in efficiency whereas the opposite may be true with strategic complements. In the second chapter we consider negotiation with an alternating offer protocol. As opposed to previous contributions we show that impatience may be beneficial for a player. In the third chapter we illustrate how the complexity of conjectures about opponents' strategies in the analogy-based expectation equilibrium (ABEE) corresponds to various other equilibrium concepts in the learning literature. We also introduce a payoff- confirming refinement of the ABEE where the sample of own payoffs induced by the true equilibrium strategies must confirm the conjectures about opponents' strategies. We show that there may be non-Bayesian-Nash payoff-confirming ABEE. We provide a sufficient condition for this and show that the condition is also necessary in an interesting class of games.

CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
A securitização desenvolvida no modelo de Steinert e Torres-Martínez(2005) é similar em muitos aspectos àquela encontrada no mercado de Mortgage- Backed Securities(MBS). Afinal, uma MBS é um título cujos fluxos de caixa são gerados por contratos de dívida garantidos por um imóvel. Porém, MBS estão sujeitas não só a risco de default, mas também a risco de pré- pagamento, já que qualquer um dos contratos de dívida que as lastreiam pode ser sempre pago, parcialmente ou integralmente, antes do vencimento pelo seu valor de face. Nesse trabalho construímos um modelo de equilíbrio geral com securitização e risco de default e pré- pagamento, tratando, assim, uma economia mais próxima ao mercado de MBS.
The securitization developed in Steinert and Torres- Martínez (2005) model is similar in many aspects to that in the market for Mortgage-Backed Securities. After all, a MBS is a bond whose cash flows are generated by debt contracts insured by a property. However, MBS are subjected not only to default but also to prepayment risk, since any debt contract backing it can be paid partially or totally by its face value before retirement. In this work, we set up a general equilibrium model with securitization and both default and prepayment risks. By doing this, we model an economy more realistic when we consider the market for MBS.

The currently accepted theory that governs the dynamics of quarks and gluons, within the Standard Model of fundamental interactions, is the Quantum Chromodynamics (QCD). Its non-abelian nature provides two important features: while at high energies the interaction becomes small and quarks and gluons interact weakly (asymptotic freedom), at low energies the interaction becomes strong and quarks are confined inside hadrons (color confinement). The asymptotic freedom of QCD implies the existence of a super-dense and ultra-hot form of matter in which the color charged particles are deconfined, the quark-gluon plasma (QGP). Many phenomenological approaches and numerical simulations of the QCD clearly indicate the existence of a transition from the hadronic matter to the quark-gluon plasma at large energy density, $\epsilon>0.5-1 GeV/fm^3$. Creating and studying the quark-gluon plasma in laboratory is one of the main challenges of experiments at the Large Hadron Collider (LHC) and at the Relativistic Heavy Ion Collider (RHIC). Through ultra-relativistic heavy ion collisions, which generate energies of $0.9-5.5 TeV$ per nucleon at LHC and $20-200 GeV$ per nucleon at RHIC, one try to get detailed information on the high temperature and low baryon density region of the phase diagram of QCD. In this thesis we present our study, within the framework of relativistic transport kinetic theory, of the formation and the dynamical evolution of the quark gluon plasma in ultra-relativistic heavy ion collisions. In particular we investigate the time scales and the mechanisms responsible of the isotropization of the fluid produced in the initial out-of-equilibrium stage of the collision, aiming at spotting the impact of this pre-equilibrium phase on collective flows of the bulk matter and on photon observables. In the first part of this thesis we present our model of the early times dynamics of relativistic heavy ion collisions, in which an initial color-electric field decays to a particle plasma by the Schwinger effect. One of the main novelties of our work consists in the coupling of field evolution to plasma dynamics by solving consistently the classical field equations and the relativistic Boltzmann equation; the self-consistent solution of the problem allows to take into account the back-reaction of the color currents on the classical field. We find that the color-electric field experiences a rapid decay for small $\eta/s$, in both 1+1D and 3+1D space-time configurations; looking at the ratio of longitudinal over transverse pressure we find that the system acquires a substantial degree of isotropy in less than 1 fm/c for $\eta/s=1/4\pi$, in agreement with the common lore of hydrodynamic approaches. In the second part of this thesis, we extend our approach up to the implementation of a realistic initial condition in which the color-electric field is smoothly distributed in the transverse plane. This configuration, relevant to heavy ion collisions at RHIC and LHC energies, allows to investigate the effect of the pre-equilibrium dynamics on observables, such as spectrum and elliptic flow of photons emitted from the quark-gluon plasma. To this end we compare the photon production starting from classical color field as discussed above with the standard initial condition of a plasma in thermal equilibrium. We find that the pre-equilibrium stage produces abundantly photons, comparable in number with those produced by the equilibrated quark-gluon plasma during the whole fireball lifetime. This early contribution enhances the spectrum mainly in a transverse momentum range ($p_T>2-3 GeV$) where thermal emission becomes less important. The pre-equilibrium phase has an impact also on the photon elliptic flow, since photons coming from the early times evolution of the fireball suppress the contribution to the momentum anisotropy brought by QGP thermal photons.

The Dynamical Dipole mode is a pre-equilibrium collective dipole oscillation predicted to be excited in charge asymmetric heavy-ion collisions. It decays emitting prompt gamma–rays and gives important information on the reaction dynamics. Its study could allow us to probe the density dependence of the symmetry energy in the Equation of State at sub-saturation densities, where this oscillation is active. Furthermore, its prompt radiation could be of interest for the synthesis of super-heavy elements in hot fusion reactions as it cools down the formed nucleus on the fusion path through emission of prompt gamma–rays. We investigated the Dynamical Dipole in fusion-evaporation and fission reactions for a composite system in the mass region of lead, a mass region never studied before. For this research the reactions 40Ca + 152Sm and 48Ca + 144Sm have been performed at ELAB = 11 MeV/nucleon at the Laboratori Nazionali del Sud, (LNS, Italy). The gamma-rays and the light charged particles were detected by using the MEDEA apparatus, made of 180 BaF2 scintillators and 6 Parallel Plates Avalanche Counters for fission fragments and evaporation residues. Any difference in the gamma-ray multiplicity spectra and the gamma-ray angular distributions of the two investigated reactions constitutes the signature of a pre-equilibrium process, i.e. the Dynamical Dipole mode excitation and its subsequent decay. From the study of these observables in the two reactions it was shown, in a model independent way, that the Dynamical Dipole survives in such a heavy composite system with similar features in both evaporation and fission events. Our results were compared with theoretical calculations performed within a BNV transport model, based on a collective bremsstrahlung analysis of the entrance channel reaction dynamics.
Il Dipolo Dinamico è un’oscillazione dipolare collettiva di pre-equilibrio che si instaura in una reazione asimmetrica in carica fra ioni pesanti. Tale oscillazione decade emettendo raggi gamma dipolari di pre–equilibrio e può fornire importanti informazioni sulla dinamica delle reazioni. Il Dipolo Dinamico consente di avere informazioni sulla dipendenza dell’equazione di Stato della materia nucleare dalla densità, per densità al di sotto di quella di saturazione, dove questa oscillazione è attiva. Inoltre, la sua emissione “pronta” potrebbe essere utile per la formazione di nuclei superpesanti in processi di fusione “calda”, come possibile meccanismo di raffreddamento del sistema composito tramite l’emissione raggi di pre–equilibrio. Il Dipolo Dinamico è stato studiato nella regione di massa del Pb, una regione di massa mai investigata finora, sia in reazioni di fusione–evaporazione che di fissione. A tale scopo sono state realizzate le reazioni 40Ca + 152Sm e 48Ca + 144Sm ad un’energia incidente ELAB = 11 MeV/nucleone presso i Laboratori Nazionali del Sud, (LNS, Italy). I raggi gamma e le particelle leggere cariche sono state rivelate usando il setup sperimentale MEDEA, composto da 180 scintillatori BaF2 e 6 rivelatori Parallel Plates Avalanche Counters per i frammenti di fissione e i residui di evaporazione. Le differenze negli spettri di molteplicità e nelle distribuzioni angolari dei raggi gamma delle due reazioni studiate indicano la presenza di un processo di pre-equilibrio, ovvero del Dipolo Dinamico e del suo conseguente decadimento tramite raggi gamma. Dal confronto di queste osservabili nelle due reazioni è stato dimostrato, in maniera indipendente dai modelli, che il Dipolo Dinamico sopravvive in un sistema composto così pesante con caratteristiche simili sia in eventi di evaporazione che di fissione. Tali risultati sono stati confrontati con calcoli teorici effettuati nell’ambito di un modello di trasporto di tipo BNV, basato su un approccio di emissione bremsstrahlung collettivo della dinamica di reazione del canale d’ingresso.

The thesis argues that, as a tradition, the concept of just war is socially and contextually sensitive and revisable. It explores the relevance of theory according to the dynamic changes in the nature of threats in the international arena and concludes that the just war tradition is still relevant to the contemporary modern threats that require an act of pre-emptive warfare. However, it needs some revision to be comprehensively applicable to the dynamic of modern threats and the nature of pre-emptive war. Due to the nature of pre-emptive war a nation launches the attack before the aggression from the other nation-in-conflict erupts. The author, therefore, proposed several theoretical and procedural revisions in both the principle of “Jus Ad Bellum” and “Jus In Bello” using the method of reflective equilibrium to create a comprehensive “just” pre-emptive war doctrine as part of the development and dynamic in just war tradition.

A projeção de expansão dos recursos petrolíferos do país a partir do pré-sal provocará, além do aumento da produção, a mudança na balança comercial do setor, tornando o Brasil um exportador líquido de petróleo e gás natural. Dada a importância do setor petrolífero para a economia de um país e sua presença como insumo em diversos setores buscou-se neste trabalho estudar os impactos desse choque de oferta na economia brasileira através de um modelo de equilíbrio geral computável dinâmico para o horizonte de 2010 a 2020. Além disso, estudaram-se os impactos de longo prazo até 2090 através de dois cenários alternativos. Um deles calibrado para simular a curva de produção do petróleo incluindo o pré-sal projetada através da modelagem de Hubbert e outro através da simulação do pré-sal como uma tecnologia subsidiada endógena ao modelo utilizado. Foram investigados os impactos macroeconômicos, setoriais, a possibilidade de doença holandesa e os impactos ambientais nos cenários de médio e longo prazo descritos. Os resultados obtidos mostram que na análise até 2020, apesar de impactar positivamente o PIB e o bem-estar do consumidor representativo, a produção do pré-sal produziu sintomas de doença holandesa, observados a partir de apreciação cambial real, impacto negativo na produção de alguns setores, assim como deslocamento de fatores produtivos entre os setores. Também houve um impacto positivo no total de emissões de gases de efeito estufa brasileiras e mundiais. No primeiro cenário de longo prazo, os resultados de impactos positivos sobre o PIB e bem-estar, sintomas de doença holandesa e aumento de emissões de gases de efeito estufa são observados até o pico de produção em 2030. E no fim do horizonte de simulação observa-se um impacto negativo sobre o PIB, bem-estar e na produção de todos os setores da economia. No segundo cenário de longo prazo os efeitos em 2090 são também negativos, mas percebe-se um impacto negativo na economia nesse cenário também no médio prazo, devido à curva de subsídios assumida que provocou uma alocação ineficiente de recursos na economia. Conclui-se a partir desses resultados que o desenvolvimento do pré-sal traz mais custos que benefícios à economia brasileira no longo prazo, considerando o atual conhecimento tecnológico. Dessa forma, são desejáveis políticas de investimento e desenvolvimento tecnológico capazes de reduzir os custos de exploração, bem como medidas capazes de reverter ou reduzir os sintomas de doença holandesa.
The projected expansion of the country\'s oil resources from the pre-salt layer will cause, beyond an increase in production, a shift in the trade balance of the sector, turning Brazil into an oil and natural gas net exporter. Given the importance of the oil sector to the country\'s economy and its presence as an input in several sectors, in this article we studied the impact of this supply shock in the Brazilian economy through a dynamic computable general equilibrium model for the 2010-2020 time horizon. Furthermore, we studied the long-term impacts until 2090 through two alternative scenarios. One calibrated to simulate the oil production curve, including the pre-salt oil projected through Hubbert\'s model and the other scenario through the simulation of the pre-salt productions as a subsidized technology endogenous to the dynamic computable general equilibrium model used. This study aimed to analyze the macroeconomic, sectorial and environmental impacts, and the possibility of Dutch disease, all in the medium and long term scenarios. The results show that, until 2020, despite positively impacting GDP and welfare of the representative consumer, the shock produced symptoms of Dutch disease that can be inferred through the results of real exchange rate appreciation, negative impact on the production of some sectors, as well as productive factor movement across sectors. In addition, the pre-salt production positively impacted total emissions of greenhouse gases in Brazil and in the world. In the first long-term scenario, the outcomes of positive impact on GDP and welfare, symptoms of Dutch disease and increased greenhouse gas emission are observed until the oil production peak in 2030. In the end of the simulation horizon, there is a negative impact on GDP, welfare and production of all the economy sectors, given the Brazilian oil curve production assumption. In the second long-term scenario, the effects in 2090 are also negative, but negative impacts on the economy in this scenario are also noted in the medium term due to the assumed subsidy curve that caused an inefficient allocation of resources in the economy. From these results it is possible to conclude that the development of the pre-salt oil implies in more costs than benefits to the Brazilian economy in the long run, considering the current technological knowledge. Thus, investment policies and technological development that can reduce operating costs are desirable, as well as policies to reverse or reduce the symptoms of Dutch disease.

Data on elastic scattering of 96 MeV neutrons from 56Fe, 89Y and 208Pb in the angular interval 10-70° are presented. The previously published data on 208Pb have been extended, as a new method has been developed to obtain additional information at the most forward angles. The results are compared with phenomenological and microscopic optical potentials. The theory predictions are in general in good agreement with the experimental data. A study of the deviation of the zero-degree cross section from Wick's limit has been performed. The data on 208Pb are in agreement with Wick's limit, while those on lighter nuclei overshoot the limit significantly. A novel analysis method has been developed to obtain the inelastic neutron emission cross sections from the existing 56Fe data. The method is based on folding a trial spectrum with the response of the detector setup. The data cover the angular interval 26-65° and an excitation energy range of 0-45 MeV, ranges hitherto not studied. The results are compared with nuclear model predictions and found to be in good agreement with the experimental data.

The purpose of this thesis is to report on the analysis done on the four reactions: 16O+30Si, 18O+28Si and 19F+27Al at 7 MeV/u e 16O+30Si at 8MeV/u, which have been measured at Legnaro National Laboratories with the GARFIELD+RCo detectors array. The idea behind this experiment is to evaluate the properties of the pre-equilibrium emission process in an energy regime close to the onset of such emission with the future project to carry out a following experiment of the same systems at higher bombarding energies, where the pre-equilibrium component is well assessed and may play a more important role. This experiment finds employment in the wider framework of an extensive research campaign on pre-equilibrium emission of light charged particles from hot nuclei made by the NUCLEX collaboratio. The study of pre-equilibrium emitted particles is a useful tool to examine nuclear clustering analyzing the effects of possible cluster structures on the nuclear reactions. After a theoretical and experimental introduction, the main analysis results are described: the quasi-complete events and complete events analysis; the study of selected evaporation residue channels; the evaluation of quantitative observables (BR and Q-value) of the major populated channels; the characterization of specific multiple (1, 2 and 3) alpha-channels.
Lo scopo di questa tesi è descrivere l'analisi fatta sulle quattro reazioni: 16O+30Si, 18O+28Si e 19F+27Al a 7 MeV/u e 16O+30Si a 8 MeV/u, effettuate presso i Laboratori Nazionali di Legnaro con l'apparato di rivelazione GARFIELD+RCo. L'idea alla base di questo esperimento è di valutare le proprietà dei processi di emissioni di pre-equilibrio in un regime energetico prossimo alla soglia di tali emissioni, con il progetto futuro di effettuare un successivo esperimento con gli stessi sistemi a energie maggiori, tali che la componente di pre-equilibrio sia preponderante. Tale esperimento si colloca nella più ampia campagna sperimentale riguardante le emissioni di pre-equilibrio di particelle cariche leggere da nuclei eccitati, effettuata dalla collaborazione NUCLEX. Lo studio delle particelle di pre-equilibrio è uno strumento utile per studiare il clustering nucleare analizzando gli effetti che esso produce sulla dinamica di reazione. Dopo un'introduzione teorica e sperimentale, i principali risultati dell'analisi saranno esposti: le analisi degli eventi quasi-completi e degli eventi completi; lo studio di specifici canali di reazione relativi ai residui di evaporazione; l’analisi quantitativa di osservabili quali il branching ratio e il Q-valore; la caratterizzazione dei canali a più (1, 2 e 3) particelle alpha.

A descoberta de petróleo na camada de Pré-Sal possibilita a geração de ganhos em relação à dependência energética do país, mas também grandes desafios econômicos e tecnológicos. Os custos de extração são maiores devido a vários fatores como a exigência de equipamentos de exploração que suportem elevadas pressões, altas temperaturas e grandes concentrações de gases ácidos, tais quais, dióxido de carbono (CO2) e sulfeto de hidrogênio (H2S). Uma das principais preocupações com o CO2 é evitar liberá-lo para a atmosfera durante a produção. Com a modelagem termodinâmica de dados de equilíbrio de sistemas envolvendo CO2 supercrítico e hidrocarbonetos é possível projetar equipamentos utilizados em processos de separação. A principal motivação do trabalho é o levantamento de dados de equilíbrio de fases de sistemas compostos de CO2 e hidrocarbonetos, possibilitando assim prever o comportamento dessas misturas. Os objetivos específicos são a avaliação do procedimento experimental, a estimação e predição dos parâmetros de interação binários para assim prever o comportamento de fases dos sistemas ternários envolvendo CO2 e hidrocarbonetos. Duas metodologias foram utilizadas para obtenção dos dados de equilíbrio: método estático sintético (visual) e método dinâmico analítico (recirculação das fases). Os sistemas avaliados foram: CO2 + n-hexano, CO2 + tetralina, CO2 + n-hexadecano, CO2 + n-hexano + tetralina e CO2 + tetralina + n-hexadecano à alta pressão; tetralina + n-hexadecano à baixa pressão. Para o tratamento dos dados foi utilizada equação de estado cúbica de Peng-Robinson e a regra de mistura clássica
The discovery of oil in the pre-salt layer enables the generation of earnings in relation to the energy dependence of the country, but also large economic and technological challenges. Extraction costs are higher due to various factors such as the demand for mining equipment capable of withstanding high pressures, high temperatures and high concentrations of acid gases, as such, carbon dioxide (CO2) and hydrogen sulfide (H2S). A major concern with CO2 is to avoid releasing it into the atmosphere during production. With the thermodynamic equilibrium modeling systems involving data supercritical CO2 and hydrocarbon is possible to design equipment used in separation processes. The main motivation is the data collection phase equilibrium compounds CO2 systems and hydrocarbons, thus enabling predict the behavior of these mixtures. The specific objectives are to assess the experimental procedure, the estimation and prediction of binary interaction parameters so as to predict the behavior of phases of ternary systems involving CO2 and hydrocarbons. Two methodologies were used to obtain the equilibrium data: synthetic static method (visual) and analytical dynamic method (recycling phase). The systems were evaluated: CO2 + n-hexane, CO2 + tetralin, CO2 + n-hexadecane, CO2 + n-hexane + tetralin, and CO2 + tetralin + n-hexadecane at high pressure; tetralin + n-hexadecane at low pressure. For the treatment of the data was used cubic equation of state of Peng-Robinson and the classical mixing rule

O Presente trabalho propôs o estudo de reações fotonucleares e fotoprodução de pions em energias intermediárias e altas usando o modelo de cascata intranuclear MCMC para a fase rápida de reação e outro algoritmo de Monte Carlo para descrever o processo de decaimento do núcleo composto via evaporação de partículas e fissão nuclear. Dentre as principais inovações implementadas no MCMC, podemos citar: i) a inclusão detalhada do canal do quase-dêuteron no intervalo 20 < Eg < 140 MeV; ii) o desenvolvimento inédito e rigoroso de um mecanismo de bloqueio de Pauli não-estocástico, avaliando as excitações partícula-buraco em tempo real na fase de pré-equilíbrio; iii) a incorporação de um critério energético de parada para a cascata; iv) a utilização de distribuições de momento apropriadas para núcleos leves (Modelo de Camadas), v) a inclusão de canais de fotoprodução do pi^0 na região da Delta (1232) e em altas energias 4,0 < Eg < 6,0 GeV e ângulos frontais e, vi) a metodologia inédita para avaliar as interações de estado final de mésons e ressonâncias com o núcleo via cenário de espalhamentos múltiplos. O mecanismo do quase-dêuteron reproduz satisfatoriamente as seções de choque totais de fotoabsorção e as multiplicidades médias de nêutrons emitidos em núcleos pesados, interpretando qualitativamente as seções de choque para os canais de eletrodesintegração (e,xnyp) do 232Th. A contribuição de um possível processo de fotoabsorção por poucos corpos no 232Th é analisada via canal de fotofissão. Os cálculos das distribuições angulares na fotoprodução incoerente do pi^0 para o 12C e 208Pb em energias intermediárias estão em ótimo acordo com dados experimentais obtidos no Microtron de Mainz (MAMI). Os resultados para as seções de choque das distribuições angulares do pi^0 em altas energias servirão como referência na Colaboração PrimEx no Jefferson Laboratory Facility, propiciando a separação da parte incoerente das demais contribuições nucleares e eletromagnéticas e auxiliando na determinação precisa da meia-vida do decaimento radiativo pi^0 --> GG.
Photonuclear reactions and pion photoproduction at intermediate and high energies have been studied using the multicollisional intranuclear cascade model (MCMC) for the rapid reaction step and another Monte Carlo algorithm to describe the de-excitation of the compound nucleus via particle evaporation and nuclear fission. The new features of the MCMC are: i) the detailed inclusion of the quasideuteron channel in the range 20 < Eg < 140 MeV; ii) the development of a rigorous and completely new non stochastic Pauli blocking mechanism, taking into account particle - hole excitations during the pre-equilibrium stage; iii) the incorporation of an energetic criterion to stop de cascade; iv) the employment of an appropriate momentum distribution for light nuclei (Shell Model); v) the inclusion of pi^0 photoproduction channels in the Delta (1232) region and at high energies 4.0 < Eg < 6.0 GeV and forward angles, and vi) the new methodology to evaluate the pion-nucleus and Delta - nucleus Final State Interactions via a multiple scattering scenario. The quasideuteron mechanism reproduces the total photoabsorption cross sections and neutron multiplicities in heavy nuclei, giving a qualitative interpretation for the cross sections of the electrodisintegration channels (e,xnyp) from 232Th. The contribution of a possible few body photoabsorption process in 232Th is evaluated via fission channel. The calculations of the pi^0 angular distributions for incoherent production at intermediate energies for 12C and 208Pb are in excellent agreement with the experimental data of the Mainz Microtron (MAMI). The results of the pi^0 angular distributions at higher energies will be reference for the PrimEx Collaboration at the Jefferson Laboratory Facility, propitiating the separation of the incoherent part from the remaining nuclear and electromagnetic contributions and helping to perform a high precision measurement of the pi^0 to gamma-gamma radiactive decay width.

Orientador : Antonio Jose de Almeida Meirelles
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Neste trabalho foi estudada a pré-purificação da proteína de fusão precursora à insulina humana e produzida por Escherichia coli modificada, utilizando-se Sistemas Aquosos Bifásicos do tipo polietileno glicol (PEG)/sal/água. A proteína de fusão foi fornecida pela empresa farmacêutica Biobrás S.A (Montes Claros/MG) e foi dissolvida em uréia 8M. Os experimentos de partição da proteína de fusão foram conduzidos de forma a identificar condições para a separação da proteína de fusão de outras proteínas e componentes celulares de E. coli. Foram realizados dois planejamentos experimentais 32 para o estudo da partição da proteína de fusão precursora da insulina humana no sistema PEG/fosfato de potássio/água. tendo-se como variáveis a massa molar do polietileno glicol, a razão mássica PEG/fosfato do sistema (RPEG/FOS). OS níveis estudados foram 1500, 3350 e 8000 para a massa molar do PEG; 1,6, 1,636 e 1,67 para RPEG/FOS. No primeiro planejamento, os testes de partição foram conduzidos a pH 9, enquanto que no segundo planejamento, os testes foram conduzidos a pH 12. Concluídos os testes com o sistema PEG/fosfato de potássio/água, foi escolhida a melhor condição para a purificação da proteína de fusão, condição esta que foi também testada para o sistema PEG/citrato de sódio/água. Para o sistema PEG/fosfato de potássio/água, o melhor resultado foi obtido com o PEG de massa molar 1500, concentração de 16% p/p PEG/l0% p/p de fosfato e pH 9, com fator de purificação da ordem de 1,5 vez e recuperação de 99%. Nestas mesmas condições, mas utilizando citrato de sódio, o fator de purificação e a recuperação foram 1,8 vez e 50,0%, respectivamente. Para analisar a proteína de fusão precursora da insulina humana, desenvolveu-se uma metodologia de análise por Cromatografia de afinidade / FPLC, usando-se a coluna Chelating Sepharose para separar a proteína de fusão dos demais componentes celulares e o Método de Bradford para quantificá-1a. Diagramas de fase do sistema PE& Na3Cit/H2O, para 3 pesos moleculares de PEG (600, 1500 e 3000) foram medidos a 25°C e modelou-se o equilíbrio líquido-líquido deste sistema usando-se o modelo VERS, baseado na equação do virial e que usa como medida de concentração uma fração de superfície externa do componente. Um ajuste muito bom aos dados experimentais foi obtido e os erros absolutos médios entre as concentrações experimentais dos componentes e as calculadas pelo modelo VERS foram 1,16%, 1,05% e 1,19% para os sistemas PEG600/ Na3Cit/H2O, PEGl500/ Na3Cit/H2O e PEG3000/ Na3Cit/H2O, respectivamente. O modelo obtido apresentou boa capacidade preditiva para a influência da massa molar do PEG sobre o equilíbrio líquido-líquido do sistema estudado. Para fins de modelagem termodinâmica, também foi estudada a partição das insulinas humana e suína puras nos sistemas PEG600/ Na3Cit/H2O, PEG1450/Na3Cit/ H2O e PEG3350/Na3Cit/ H2O em pH 4,5, 7 e 9,5 a 25°C para modelar a partição da insulina no sistema PEG/ Na3Cit/ H2O, utilizando-se também o modelo VERS e bons resultados foram obtidos para a -predição do coeficiente de partição da insulina suína no sistema PEG/ Na3Cit/H2O a pH 7,0
Abstract: In this work the primary purification of a fusion protein precursor of human insulin and produced by recombinant E. coli has been studied using aqueous two-phase systems. The fusion protein was provided by the pharmaceutical company Biobrás S.A (Montes Claros/Brazil) and was dissolved in 8M area. Partitioning essays of fusion protein were investigated in the poly(ethylene glycol) (PEG)/potassium phosphate and poly(ethylene glycol)/sodium citrate aqueous two-phase systems at 25°C. Two 32 experimental design were done to evaluate the effects of PEG molecular weight and the polymer/salt concentration ratio on the purification factor and on the recovery of the fusion protein in the top phase. The studied levels were 1500, 3350 and 8000 for PEG molecular weight and 1,6; 1,636 and 1,67 for the polymerlsaIt concentration ratio. The partitioning experiments were performed at pH 9 and 12. An analytical method for the fusion protein was developed using Immobilized Metal Affinity Chromatography and the Bradford method. Solids on the interface top were observed in all cases examined The fusion protein partitioned between the PEG-rich phase and the solids on interface. Contaminating proteins were eliminated to some extent, which resulted in an almost 2-fold fusion protein purification with good recoveries. Phase diagrams of the system poly(ethylene glycol)1 sodium citrate/water were determined for three different molecular weights of PEG ( 600, 1500, 3000) at 25°C. At least four tie-lines of each system were measured. The experimental results were correlated by applying a model for the excess Gibbs energy. This model is the Virial equation used by Pitzer for salt solutions, but concentrations are expressed by surface fraction. It is called Virial Equation with Relative Surface fractions (VERS). All phase equilibrium calculations were performed using this model and minimizing the Gibbs energy of the feed under the constraint that both phases are electroneutral. Agreement between the experimental and calculated results within the experimental uncertainty was obtained. The average percents of deviation between experimental and calculated values using VERS model for all components were 1,16%, 1,05% and 1,19% for the systems PEG6001 Na3Cit/H2O, PEGl500/ Na3Cit/H2O PEG30001 Na3Cít/ H2O respectively. Human and porcine insulin partitioning was investigated in the system PEG/sodium citrate/water for three pHs (4,5; 7 and 9,5) at 25°C. Human and porcine insulin showed great affinity for the PEG-rich phase and the partition coefficients were higher than 10. The human insulin partition coefficient is practically independent of the PEG molecular mass. However, there is a tendency for the porcine insulin partition coefficient to increase with the PEG molecular mass at pH 7 and 9,5, attaining values- above 50. The porcine insulin partition coefficient was predicted in the system PEG/sodium citrate/water at 25°C using VERS model and good results were obtained for the system at pH 7
Doutorado
Mestre em Engenharia de Alimentos

The subject of the diploma thesis is the design and static analysis of roof structure. It is prestressed roof shell (membrane) supported by a cable. The whole thesis is divided into several separated units according to task's specification. The text section describes the introduction to the issue of presstressed suspension cable constructions and displays their possible shapes, types and realizations. There is also technical report of solved shell, which was written on the base of the documents, drawn drawings and structural (static) analysis.

碩士
國立中興大學
應用數學系
93
We develop a new mathematical model and computer simulations for SELEX (Systematical Evolution of Ligands by EXponential enrichment) experiments. By considering binding and dissociation rates of ligands and targets, we investigate quantitatively the effect of incubation time of binding reactions on the enrichment of high affinity ligands. We incorporate partition efficiency, background contamination and initial winner frequency in our simulations. In most cases, we find that with insufficient incubation times SELEX can still generate aptamers for targets, yet the full enrichment of the ligand library is at the expense of selection cycles.

The thesis describes the complex procedure of data reduction and analysis of a heavy-ion nuclear physics experiment performed at LNL in Legnaro (Italy). The experiment was focused on the reaction mechanism characterization at energies between the mean field region and the Fermi energy regime. Pre-equilibrium and isospin transport phenomena were also put into evidence. The results were compared with the literature and with advanced dynamical models.

Efficient algorithms exist for finding optimal strategies in extensive-form games. However human scale problems, such as poker, are typically so large that computation of these strategies remain infeasible with current technology. State space abstraction techniques allow us to derive a smaller abstract game, in which an optimal strategy can be computed and then used in the real game. This thesis introduces state of the art abstraction techniques. Most of these techniques do not deal with public information. We present a new automatic public state space abstraction technique. We examine the quality of this technique in the domain of poker. Our experimental results show that the new technique brings significant performance improvement. Powered by TCPDF (www.tcpdf.org)

Indiana University-Purdue University Indianapolis (IUPUI)
The life expectancy of humans in today's era have increased to a very large extent due to the advancement of medical science and technology. The research in medical science has largely been focused towards developing methods and medicines to cure a patient after a diagnosis of an ailment. It is crucial to maintain the quality of life and health of the patient. It is of most importance to provide a healthy life to the elderly as this particular demographic is the most severely affected by health issues, which make them vulnerable to accidents, thus lowering their independence and quality of life. Due to the old age, most of the people become weak and inefficient in carrying their weight, this increases the probability of falling when moving around. This research of iterative nature focuses on developing a device which works as a preventive measure to reduce the damage due to a fall. The research critically evaluates the best approach for the design of the Pre-Fall detection system. In this work, we develop two wearable Pre-Fall detection system with reduced hardware and practical design. One which provides the capability of logging the data on an SD card in CSV format so that the data can be analyzed, and second, capability to connect to the Internet through Wifi. In this work, data from multiple accelerometers attached at different locations of the body are analyzed in Matlab to find the optimum number of sensors and the best suitable position on the body that gives the optimum result. In this work, a strict set of considerations are followed to develop a flexible, practical and robust prototype which can be augmented with different sensors without changing the fundamental design in order to further advance the research. The performance of the system to distinguish between fall and non-fall is improved by selecting and developing the most suitable way of calculating the body orientation. The different ways of calculating the orientation of the body are scrutinized and realized to compare the performance using the hardware. To reduce the number of false positives, the system considers the magnitude and the orientation to make a decision.

A thesis submitted to the Wits School of Education, Faculty of Humanities, University of the Witwatersrand, in fulfillment of the requirements of the degree of Doctor of Philosophy. Johannesburg, 2012
Reflection about lessons delivered is a practice widely encouraged in teaching. Reasoning, particularly about transformation of subject matter knowledge of lessons yet to be taught, is an internal process and a speciality evident largely in expert teachers. The study investigates the feasibility of fast-tracking its development in pre-service chemistry teachers. It focuses on developing this specialty within a specific topic, as a theoretical construct called Topic Specific PCK (TSPCK). Five knowledge components of TSPCK are identified as the enablers that transform subject matter knowledge. The components are: (1) students’ prior knowledge, (2) curricular Saliency, (3) what is difficult to teach (4) representations, including powerful analogies, and (5) conceptual teaching strategies. These components are identified, with reference to literature, as aspects specific to the subject matter knowledge of the teacher and useful in its teachability. A new tool to measure the quality of TSPCK is developed. The procedure for developing the tool consists of the following steps: (i) confirming the characteristics of the test items fitting the Topic Specific PCK construct, (ii) production of test items, (iii) judgment of items, (iv) construction of the instrument (v) piloting and (vi) validation of the instrument. Care is taken to ensure presentation of multiple evidence and discussions, addressing the interpretive and arguments as requirements for showing validity of the construct measured by the instrument. The Topic Specific PCK tool is validated with a group of 20 practicing teachers. The tool is scored, using a rubric corresponding to the five components with each being rated on a four point scale, from 1 (Limited) to 4 (Exemplary). The analysis of the generated scores is done using the Rasch statistical model (Winstep, version 3.72.3). The reliability indices as indicated by person reliability and item reliability are found to be high at 0.86 at 0.91, respectively. The persons and item scores reflect measures well inside the conventionally acceptable range of -2 and +2. A further indicator of validity of the tool is the empirically calculated hierarchy of test items’ order of difficulty, found similar to the theoretically predicted pattern for the teacher group. Based on the above analysis and findings, I regard the tool as valid and reliable. My research design is based on mixed-methods research (MM). The research strategy takes the form of a case study. The study is located in a methodology class for final year physical science pre-service teachers. They formed an experimental group (N=16) for this study. I delivered an intervention, targeting understanding of transformation of Chemical Equilibrium concepts, using the above listed five knowledge components. I collected data through a combination of tools, including the newly designed Topic Specific PCK tool in Chemical Equilibrium, an Achievement tool and a science teacher Belief tool. Both the Achievement and the Belief tools were adapted from existing tools, and were thus considered tried and validated. The findings suggest that the quality of Topic Specific PCK in chemical equilibrium may be improved in pre-service teachers by the explicit discussion of the knowledge enabling its transformation. They also suggest that, in the process of discussing aspects of subject matter knowledge related to its transformation, pre-service teachers improve their conceptual understanding of chemical equilibrium. Both these improvements were not affected by the shift or lack of shift in teacher beliefs from teacher-centred towards studentcentred practices. I acknowledge the small size of the sample as a practical limitation to the generalization of the statistical findings in this study. I suggest that emphasis be placed on the trends displayed, as they are similar to those obtained from the multiple sources of the qualitative component of the study. Finally, I recommend that the development of PCK in pre-service teachers be considered in a topic by topic manner. I urge that the teaching of chemistry topics be explicitly organized in a format in which pre-service teachers would be expected to reason about them, and particularly transform them for teaching. Keywords Pedagogical Content Knowledge, Topic Specific PCK, Chemical Equilibrium, Transformation of Subject Matter Knowledge.