A scheme, analogous to the linear combination of atomic orbitals (LCAO), is used to calculate rates of reactions for the fusion of nuclei con¯ned in molecules. As an example, the possibility of nuclear fusion in rotationally excited H2O molecules of angular momentum 1¡ is estimated for the p + p + 16O ! 18Ne¤(4:522; 1¡) nuclear transition. Due to a practically exact agreement of the energy of the Ne resonance and of the p + p + 16O threshold, the possibility of an enhanced transition probability is investigated. / Physics / M.Sc.

Les premières étapes d’activation des lymphocytes T sont cruciales pour déterminer leur comportement, ainsi que leur prolifération. Ces étapes dépendent fortement des conditions initiales, particulièrement de l’avidité du récepteur du lymphocyte (TCR) pour le ligand spécifique provenant de l’antigène. La reconnaissance du virus entraine une séquence des réactions biochimiques mettant en œuvre de protéines membranaires et cellulaires. Le processus peut être mesuré par cytométrie en flux. On propose ici plusieurs modèles de différents niveaux de complexité. Ces modèles décrivent une relation entre la population de lymphocytes T et leurs composants intracellulaires et extracellulaires. Ils conduisent à des systèmes d’EDO et d’EDP dont la résolution permet d’étudier la dynamique de la densité de population des lymphocytes au cours du processus d'activation. En outre, différentes hypothèses sont proposées pour le processus d'activation des cellules filles après prolifération. Les équations de bilan de population (EBPs) sont résolues par une nouvelle méthode validée par une solution analytique quand elle existe, ou par comparaison à différentes méthodes numériques disponibles dans la littérature. L’avantage de cette nouvelle méthode est d’être utilisable dans certains cas où les méthodes classiques ne le sont pas. / The early steps of activation are crucial in deciding the fate of T-cells leading to the proliferation. These steps strongly depend on the initial conditions, especially the avidity of the T-cell receptor for the specific ligand and the concentration of this ligand. The recognition induces a rapid decrease of membrane TCR-CD3 complexes inside the T-cell, then the up-regulation of CD25 and then CD25–IL2 binding which down-regulates into the T-cell. This process can be monitored by flow cytometry technique. We propose several models based on the level of complexity by using population balance modeling technique to study the dynamics of T-cells population density during the activation process. These models provide us a relation between the population of T-cells with their intracellular and extracellular components. Moreover, the hypotheses are proposed for the activation process of daughter T-cells after proliferation. The corresponding population balance equations (PBEs) include reaction term (i.e. assimilated as growth term) and activation term (i.e. assimilated as nucleation term). Further the PBEs are solved by newly developed method that is validated against analytical method wherever possible and various approximate techniques available in the literature.

Os experimentos realizados e apresentados nesta dissertação resultaram na caracterização neutrônica de núcleos na configuração cilíndrica com 30 varetas combustíveis de diâmetro com um espaço, criado pela retirada de 16 varetas centrais, preenchido com água leve (H2O) ou água pesada (D2O) no reator nuclear de pesquisa IPEN/MB-01. Nestes núcleos, efetuou-se experimentos de correlação de canais nucleares, calibração de barras de controle e irradiação de detectores de ativação de diversos materiais em forma de folhas, cujas faixas energéticas de atuação abrangem grande parte do espectro de nêutrons do núcleo do reator, para a obtenção de parâmetros nucleares, como excessos de reatividade, reatividades totais, atividades saturadas por núcleo alvo, razões espectrais, razões de cádmio e fluxo de nêutrons multigrupo. Com a irradiação de fios de ativação de ouro na parte radial foram obtidas as formas espaciais dos fluxos de nêutrons térmicos e epitérmicos. Os resultados mostraram as características espectrais dessa nova configuração com o espaço das 16 varetas combustíveis preenchido com os dois materiais moderadores. No espaço com a água leve houve um aumento significativo de 294% do fluxo de nêutrons térmicos em comparação com a configuração padrão retangular de 28×26 varetas combustíveis. Com a água pesada aumentou-se a reatividade do sistema com ρ = (783 ± 54) pcm a mais de excesso de reatividade que na configuração com água leve. Os resultados calculados foram simulados nos códigos computacionais MCNP5, SANDBP e CITATION, onde se obtiveram resultados acurados e precisos para as atividades saturadas por núcleo alvo, as distribuições energéticas e espaciais dos fluxos de nêutrons da parte ativa e de parte do refletor e as comparações diretas das seções de choque entre as razões espectrais experimentais e calculadas. / The experiments performed and presented in this thesis results in the neutronic characterization of the core with cylindrical configuration with 30 fuel rods diameter and a space, created by the removal of 16 central rods, filled with light water (H2O) or heavy water (D2O) in the IPEN/MB-01 nuclear research reactor. In these cores were performed experiments of nuclear channels correlation, control rod worth and irradiation of activation detectors of various materials in foils shapes, whose energy performances cover much of the reactor core neutron spectrum, to obtain nuclear parameters, such as, reactivity excesses, total reactivities, saturated activities per target nucleus, spectral ratios, cadmium ratios and multigroup neutron flux. Activation gold wires detectors were irradiated in radial part to obtain the spatial forms of thermal and epithermal neutron fluxes. The results show the spectral characteristics of this new configuration with the space of 16 fuel rods filled with the two moderator materials. In the space with light water there was a significant increase of 294% of the thermal neutron flux compared to standard rectangular configuration of 28×26 fuel rods. With heavy water the system reactivity was increased, more ρ = (783 ± 54) pcm in excess reactivity than in the light water configuration. The calculated results were simulated in computational codes MCNP5, SANDBP and CITATION, where accurate and precise results were obtained for saturated activities per target nucleus, the energy and spatial distributions of the neutron fluxes for the active part and part of the reflector and the direct comparisons of cross sections between the experimental and calculated spectral ratios.

Os experimentos realizados e apresentados nesta dissertação resultaram na caracterização neutrônica de núcleos na configuração cilíndrica com 30 varetas combustíveis de diâmetro com um espaço, criado pela retirada de 16 varetas centrais, preenchido com água leve (H2O) ou água pesada (D2O) no reator nuclear de pesquisa IPEN/MB-01. Nestes núcleos, efetuou-se experimentos de correlação de canais nucleares, calibração de barras de controle e irradiação de detectores de ativação de diversos materiais em forma de folhas, cujas faixas energéticas de atuação abrangem grande parte do espectro de nêutrons do núcleo do reator, para a obtenção de parâmetros nucleares, como excessos de reatividade, reatividades totais, atividades saturadas por núcleo alvo, razões espectrais, razões de cádmio e fluxo de nêutrons multigrupo. Com a irradiação de fios de ativação de ouro na parte radial foram obtidas as formas espaciais dos fluxos de nêutrons térmicos e epitérmicos. Os resultados mostraram as características espectrais dessa nova configuração com o espaço das 16 varetas combustíveis preenchido com os dois materiais moderadores. No espaço com a água leve houve um aumento significativo de 294% do fluxo de nêutrons térmicos em comparação com a configuração padrão retangular de 28×26 varetas combustíveis. Com a água pesada aumentou-se a reatividade do sistema com ρ = (783 ± 54) pcm a mais de excesso de reatividade que na configuração com água leve. Os resultados calculados foram simulados nos códigos computacionais MCNP5, SANDBP e CITATION, onde se obtiveram resultados acurados e precisos para as atividades saturadas por núcleo alvo, as distribuições energéticas e espaciais dos fluxos de nêutrons da parte ativa e de parte do refletor e as comparações diretas das seções de choque entre as razões espectrais experimentais e calculadas. / The experiments performed and presented in this thesis results in the neutronic characterization of the core with cylindrical configuration with 30 fuel rods diameter and a space, created by the removal of 16 central rods, filled with light water (H2O) or heavy water (D2O) in the IPEN/MB-01 nuclear research reactor. In these cores were performed experiments of nuclear channels correlation, control rod worth and irradiation of activation detectors of various materials in foils shapes, whose energy performances cover much of the reactor core neutron spectrum, to obtain nuclear parameters, such as, reactivity excesses, total reactivities, saturated activities per target nucleus, spectral ratios, cadmium ratios and multigroup neutron flux. Activation gold wires detectors were irradiated in radial part to obtain the spatial forms of thermal and epithermal neutron fluxes. The results show the spectral characteristics of this new configuration with the space of 16 fuel rods filled with the two moderator materials. In the space with light water there was a significant increase of 294% of the thermal neutron flux compared to standard rectangular configuration of 28×26 fuel rods. With heavy water the system reactivity was increased, more ρ = (783 ± 54) pcm in excess reactivity than in the light water configuration. The calculated results were simulated in computational codes MCNP5, SANDBP and CITATION, where accurate and precise results were obtained for saturated activities per target nucleus, the energy and spatial distributions of the neutron fluxes for the active part and part of the reflector and the direct comparisons of cross sections between the experimental and calculated spectral ratios.

A scheme, analogous to the linear combination of atomic orbitals (LCAO), is used to calculate rates of reactions for the fusion of nuclei con¯ned in molecules. As an example, the possibility of nuclear fusion in rotationally excited H2O molecules of angular momentum 1¡ is estimated for the p + p + 16O ! 18Ne¤(4:522; 1¡) nuclear transition. Due to a practically exact agreement of the energy of the Ne resonance and of the p + p + 16O threshold, the possibility of an enhanced transition probability is investigated. / Physics / M.Sc.

Orientador: Edevar Luvizotto Junior / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-09T19:18:58Z (GMT). No. of bitstreams: 1 Trimboli_MarceloJose_M.pdf: 5392045 bytes, checksum: cc7d8b290241329ec9e101fc336f718c (MD5) Previous issue date: 2006 / Resumo: Neste trabalho são estudadas e avaliadas as etapas que visam a aplicação de modelagem matemática para obtenção de parâmetros de qualidade como a concentração de cloro livre residual em sistemas de abastecimento de água. Como estudo de caso e avaliação da proposição fui empregado o setor de abastecimento de Vila Liberdade na Cidade de Jundiaí-SP. Os resultados foram comparados com medições exaustivas de campo / Abstract: This work were studied and evaluated the stages that look for the use of the mathematics modeling to get parameters of quality like residual free chlorine concentration in network pipes . How case study and valuation of the proposition it was used the water supply sector of Vila Liberdade in the town of Jundiai - estate of São Paulo, BraziL The results were compared with exhaustive field measures / Mestrado / Recursos Hidricos / Mestre em Engenharia Civil

Lithium-oxygen batteries, also known as Lithium-air batteries, could possibly revolutionize energy storage as we know. By letting lithium react with ambient oxygen gas very large theoretical energy densities are possible. However, there are several challenges remaining to be solved, such as finding suitable materials and understanding the reaction, before the lithium-oxygen battery could be commercialized. The scope of this thesis is focusing on the latter of these challenges. Efficient ion transport between the electrodes is imperative for all batteries that need high power density and energy efficiency. Here the mass transport properties of lithium ions in several different solvents was evaluated. The results showed that the lithium  mass transport in electrolytes based on the commonly used lithium-oxygen battery solvent dimethyl sulfoxide (DMSO) was very similar to that of conventional lithium-ion battery electrolytes. However, when room temperature ionic liquids were used the performance severely decreased. Addition of Li salt will effect the oxygen concentration in DMSO-based electrolytes. The choice of lithium salt influenced whether the oxygen concentration increased or decreased. At one molar salt concentration the highest oxygen solubility was 68 % larger than the lowest one. Two model systems was used to study the electrochemical reaction: A quartz crystal microbalance and a cylindrical ultramicroelectrode. The combined usage of these systems showed that during discharge soluble lithium superoxide was produced. A consequence of this was that not all discharge product ended up on the electrode surface. During discharge the cylindrical ultramicroelectrodes displayed signs of passivation that previous theory could not adequately describe. Here the passivation was explained in terms of depletion of active sites. A mechanism was also proposed. The O2 and Li+ concentration dependencies of the discharge process were evaluated by determining the reactant reaction order under kinetic and mass transport control. Under kinetic control the system showed non-integer reaction orders with that of oxygen close to 0.5 suggesting that the current determining step involves adsorption of oxygen. At higher overpotentials, at mass transport control, the reaction order of lithium and oxygen was zero and one, respectively. These results suggest that changes in oxygen concentration will influence the current more than that of lithium. During charging not all of the reaction product was removed. This caused an accumulation when several cycles was examined. The charge reaction pathway involved de-lithiation and bulk oxidation, it also showed an oxygen concentration dependence. / Litiumsyrebatteriet, även känt som litiumluftbatteriet, kan potentiellt revolutionera vårt förhållande till energilagring. Genom att låta litium reagera med syrgas från luften kan teoretiskt höga energitätheter uppnås. Dock så behöver många problem lösas, så som att hitta lämpliga elektrod- och elektrolytmaterial samt att få en ökad förståelse för reaktionsmekanismen, innan litiumsyrebatteriet kan kommersialiseras. Den här avhandlingen behandlar de sistnämnda av dessa problem. För att ett batteri ska kunna leverera hög effekttäthet och energieffektivitet krävs en effektiv jontransport mellan elektroderna. Här utvärderades masstransporten hos flera olika elektrolyter. Resultatet visade att masstransporten av litium i en litiumsyrebatterielektrolyt (baserad på dimetylsulfoxid (DMSO)) är likvärdig med en konventionell litiumjonbatterielektrolyt. När elektrolyter baserade på jonvätskor användes uppvisades väldigt stora energiförluster. När litiumsalt tillsattes påverkades lösligheten av syre i DMSO-baserade elektrolyter. Vilken sorts litiumsalt som användes påverkade om lösligheten av syre ökade eller minskade. Vid en saltkoncentration på en molar var den högsta syrelösligheten 68 \% större än den lägsta. Två olika modellsystem används för att studera den elektrokemiska reaktionen: En elektrokemisk kvartskristallmikrovåg och en cylindrisk ultramikroelektrod. Vid kombinerad användning av dessa system påvisades att löslig litiumsuperoxid bildades vid urladdningen. Följden av detta blev att endast delar av urladdningsprodukten hamnade på elektroden. Vid urladdning visade ultramikroelektroderna tecken på passivering som inte kunde beskrivas av tidigare teori. Här föreslås att passiveringen uppstår på grund av en blockering av de aktiva säten där reaktionen fortskrider. För denna process föreslås även en detaljerad mekanism. Urladdningsprocessens koncentrationsberoende utvärderades genom att bestämma reaktionsordningen för syre och litium under kinetisk- och masstransport kontroll. Under kinetisk kontroll fanns inga heltalsreaktionsordningar, för syre var reaktionsordningen nära 0.5 vilket föreslår att det reaktionssteg som bestämmer strömstorleken innefattar en adsorption av syre. Vid högre överpotentialer, då systemet var under masstransportkontroll, var reaktionsordningarna för litium och syre noll respektive ett. Detta föreslår att ändringar i syrekoncentration påverkar strömmen betydligt mer än vad det gör för litium. Under uppladdning kunde inte all reaktionsprodukt avlägsnas från elektroden. Detta ledde till en ackumulation då flera cykler studerades. Uppladdningens delsteg innefattade en delitiering följt av en oxidation av reaktionsproduktbulken. Denna process uppvisade även ett syrekoncentrationsberoende. / <p>QC 20171114</p>

Aim of magister´s thesis was to study reaction kinetics of dental materials. Thesis was focused on dimethacrylate dental polymers, which are for example used for dental restoration, tooth repair and creating now teeth. First part of the thesis concentrates on influence of molar ratio on reation kinetics by addition of other monomer to polymer resin. Second part concentrates on influence of addition of additive silica on reaction kinetics of polymerization. Essential variables know as a polymerization ratio, conversion, gel point, glass transition temperature and storage modulus were studied. Firstly, polymerization ratio and conversion were observed by differential scanning calorimetry (DSC). Secondly rheology was observed by photoreometr. Finally, glass transition temperature and storage modulus were observed by dynamic mechanical analysis (DMA). Behaviour changes caused by addion of monomer or filler point out decrease of polymeration ratio and converstion. Same behaviour was observed by short exposure. In order to established network formation, values of gel point increased by higher concentration of monomer or filler. Glass transition temperature and storage modulus measured by DMA were evaluated. Those valuables had variable tendency due to monomer acting like filler at higher concentration. Also contradictory impact of different material conversion and filler concetration was discussed.

Nowadays there is research into molten salt reactors. The use of chlorine-based salts, which would be more available than known fluoride salts, is envisaged. The subject of research is not only the chemical and physical properties of chloride salts, but also their behavior in the neutron field and the influence of neutron balance inside the reactor. Many properties can also be determined using calculations that draw information from scientific nuclear libraries (endf). The purpose of this work is to compare important nuclear libraries with each other, and also to compare the reaction rates calculated from the library data with the reaction rates obtained by self-measurement. The preview will include a description of the necessary activities associated with the preparation of measurements, instructions for compiling the computer program NJOY and the process of the measurement itself. At the end of the work will be summarized the results and statements of which nuclear library is the closest in its values to the results of experiments.

Title: Differences in reaction rate in children with ADHD and the general population of the same age. Problem definition: ADHD is a neuropsychological disorder occurring in part of the pediatric population (5-8%). The scientific public mentions the existence of the so-called hyperfocus, ie the ability to significantly concentrate in children diagnosed with ADHD, especially in the case of these children being interested in the task. Methodologically correctly compiled and performed testing of the reaction rate of these children could confirm or refute this assumption. Aims: The aim of the work is to find out whether and possibly what effect the diagnosis of ADHD in children has on the reaction rate. Hypotheses: H1: The reaction rate in individuals with ADHD will be on average the same or higher than in individuals of the same age of the healthy population. H2: The difference between the individual experiments will be greater in children with ADHD than in individuals of the same age of the healthy population. H3: The individual with fastest reaction ability with ADHD will have the same or better result as the individual with the fastest reaction of the same aged healthy population. Methods: Testing for the purposes of this diploma thesis took place in the ROSA center. 12 probands in the tested group...