Simulações de sais de carbonato fundidos pelo método de Dinâmica Molecular (MD) foram efetuadas com o modelo polarizável de cargas flutuantes (FC). O modelo de cargas flutuantes implementa os efeitos de polarização pelo método de Lagrangiano estendido, onde as variáveis extras são as próprias cargas parciais do íon poliatômico. O modelo FC foi parametrizado por meio de cálculos ab inito, aplicado ao ânion carbonato. Cálculos de Química Quântica ab initio foram utilizados para corroborar o modelo proposto para o ânion carbonato. Os sistemas investigados consistem em misturas de carbonatos alcalinos fundidos, Li2CO3/K2CO3, os quais são utilizados como eletrólitos em células a combustível. As simulações MD foram utilizadas para verificar o efeito da polarização dos ânions sobre a estrutura e dinâmica do líquido. Estudamos o efeito da inclusão de polarização sobre a condutividade do eletrólito. / Simulations of molten carbonate salts by the method of Molecular Dynamics (MD) have been performed with the fluctuanting charge (FC) model. The FC model implements the effect of polarization by using method of extended Lagrangian, where the extra variables are the partial charges of the poliatomic ion. The FC model was parametrized by ab inito calculations os a single carbonate anion. Quantum Chemistry calculations bave been used to corroborate the model for the carbonate anion. The investigated systems consist of alkaline carbonate mixtures, Li2CO3/K2CO3, which are used as electrolytes in fuel cells. MD simulations have been used to verify polarization effects on structure and dynamics of the liquid. We study the effect of including anion polarization on the condutivity of the electrolyte.

Le but principal de cette thèse était d'étudier les caractéristiques de la matière organique dissoute (MOD) dans le bassin versant de la Seine. Ce travail a été réalisé dans le cadre du programme de recherche PIREN-Seine. Les travaux présentés ici visaient plus particulièrement à identifier les sources de MOD et à suivre son évolution dans les zones d’étude. L’analyse des propriétés optiques (UV-Visible, fluorescence) de la MOD, couplée aux traitements PARAFAC et ACP, a permis de discriminer différentes sources de MOD et de mettre en évidence des variations spatio-temporelles de ses propriétés. L’axe Seine, en aval de Paris, a notamment été caractérisé par l'activité biologique la plus forte. La MOD du bassin de l’Oise a montré des caractéristiques plus "humiques", tandis que le bassin de la Marne a été caractérisé par un troisième type spécifique de MOD. Il a d’autre part été mis en évidence la présence de MODs spécifiques dans chaque zone pour les échantillons prélevés en périodes d’étiage, alors qu’une distribution homogène des composants a été obtenue pour l’ensemble des échantillons prélevés en période de crue.Le rôle environnemental des colloïdes naturels étant étroitement lié à leur taille, il a d’autre part été développé une technique analytique/séparative originale pour l’étude de ce matériel complexe, un fractionnement par couplage flux/force avec flux asymétrique (AF4). Le fractionnement par AF4 des échantillons a confirmé la variabilité spatio-temporelle en composition et en taille de la MOD d'un site de prélèvement à un autre et a permis de distinguer différentes sources de MOD colloïdale confirmant les résultats de l’étude de ses propriétés optiques. / The main goal of this thesis was to investigate the characteristics of dissolvedorganic matter (DOM) within the Seine River catchment in the Northern part of France. ThisPhD thesis was performed within the framework of the PIREN-Seine research program. Theapplication of UV/visible absorbance and EEM fluorescence spectroscopy combined toPARAFAC and PCA analyses allowed us to identify different sources of DOM andhighlighted spatial and temporal variations of DOM properties. The Seine River wascharacterized by the strongest biological activity. DOM from the Oise basin seemed to havemore "humic" characteristics, while the Marne basin was characterized by a third specifictype of DOM. For samples collected during low-water periods, the distributions of the 7components determined by PARAFAC treatment varied between the studied sub-basins,highlighting different organic materials in each zone. A homogeneous distribution of thecomponents was obtained for the samples collected in period of flood.Then, a semi-quantitative asymmetrical flow field-flow fractionation (AF4) methodology wasdeveloped to fractionate DOM. The following optimized parameters were determined: across-flow rate of 2 ml min-1 during the focus step with a focusing time of 2 min and anexponential gradient of cross-flow from 3.5 to 0.2 ml min-1 during the elution step. Thefluorescence properties of various size-based fractions of DOM were evaluated by applyingthe optimized AF4 methodology to fractionate 13 samples, selected from the three sub-basins.The fluorescence properties of these fractions were analysed, allowing us to discriminatebetween the terrestrial or autochthonous origin of DOM.

Simulações de sais de carbonato fundidos pelo método de Dinâmica Molecular (MD) foram efetuadas com o modelo polarizável de cargas flutuantes (FC). O modelo de cargas flutuantes implementa os efeitos de polarização pelo método de Lagrangiano estendido, onde as variáveis extras são as próprias cargas parciais do íon poliatômico. O modelo FC foi parametrizado por meio de cálculos ab inito, aplicado ao ânion carbonato. Cálculos de Química Quântica ab initio foram utilizados para corroborar o modelo proposto para o ânion carbonato. Os sistemas investigados consistem em misturas de carbonatos alcalinos fundidos, Li2CO3/K2CO3, os quais são utilizados como eletrólitos em células a combustível. As simulações MD foram utilizadas para verificar o efeito da polarização dos ânions sobre a estrutura e dinâmica do líquido. Estudamos o efeito da inclusão de polarização sobre a condutividade do eletrólito. / Simulations of molten carbonate salts by the method of Molecular Dynamics (MD) have been performed with the fluctuanting charge (FC) model. The FC model implements the effect of polarization by using method of extended Lagrangian, where the extra variables are the partial charges of the poliatomic ion. The FC model was parametrized by ab inito calculations os a single carbonate anion. Quantum Chemistry calculations bave been used to corroborate the model for the carbonate anion. The investigated systems consist of alkaline carbonate mixtures, Li2CO3/K2CO3, which are used as electrolytes in fuel cells. MD simulations have been used to verify polarization effects on structure and dynamics of the liquid. We study the effect of including anion polarization on the condutivity of the electrolyte.

Optical parameters measured via absorption spectroscopy and high-resolution fluorescence spectroscopy were used to characterize dissolved organic matter (DOM) in the springshed of Kings Bay, a spring-fed estuary located on Florida's Springs Coast. Over the past 40 years, springs supplying groundwater to Kings Bay have shown an increase in nitrate concentration. The overall goal of this project was to fingerprint wells and spring sites with elevated nitrogen concentrations using CDOM optical properties and establish relationships between nutrient and optical parameters. Samples were obtained from various sites: springs, Kings Bay surface (KBS), wells, coastal waters in and at the mouth of Crystal River (Coast) and lakes and rivers (LNR), during dry and wet seasons. The relationships between the environmental parameters and traditional optical parameters which provide insight into source characteristics were analyzed. Excitation emission matrix spectroscopy (EEMS) provided information about the concentration and chemical nature of organic matter in the study area. CDOM optical properties combined with salinity clearly separated the sources of fixed nitrogen in the Bay. Northern springs with elevated dissolved inorganic nitrogen (DIN) concentration had lower salinities and showed a presence of protein peaks. CDOM concentration was negatively correlated with total nitrogen (TN) and DIN, which suggests that these are subjected to anthropogenic influences. Humic peaks dominated the composition of the southern springs. CDOM concentrations were much higher than in the northern springs and there was a positive correlation between CDOM and both TN and DIN. These findings suggest that the fixed nitrogen in the southern springs is naturally occurring organic matter and the low concentrations may partially be a result of subsurface mixing of saltwater and freshwater in the aquifer. Thus, hypothesis testing showed that there was a significant difference between northern and southern springs Hypothesis testing also showed that there is a significant and unexpected positive relationship between CDOM and salinity studying Kings Bay, which is due to the low CDOM concentration in the springs discharging fresh water. This unique dataset also determined that the intercept of the mixing line was significantly different form zero. This indicates that CDOM is present and detectable at very low concentrations. Parallel Factor Analysis (PARAFAC) was used to evaluate CDOM composition from excitation emission matrix spectra (EEMs) and five components were identified: two humic, two marine humic, and one protein-like. The marine-like components, peak M, were produced in the marine environment and in meteoric groundwater. The study found a unique groundwater marker for coastal regions. Northern Kings Bay sites were characterized by a protein-like component, which has been associated with wastewater. Additional optical and environmental parameters were used in discriminate analysis, which successfully identified the CDOM markers for both natural and anthropogenic sources of nutrients in the environment. It is vital to improve the analysis of water, nutrients, and carbon from groundwater discharge into the coastal zone. Elevated DIN concentrations in groundwater are a widespread problem in Florida and over the past 30 years many spring waters have shown an increase in DIN concentrations. Nutrient discharge into delicate coastal areas can lead to ecological concerns. Investigating CDOM and nutrient distribution together can be a beneficial tool that can help differentiate sources from riverine/lacustrine, estuarine, marine, groundwater, and sewage impacted categories.

Philosophiae Doctor - PhD / Electroanalytical and optical properties of nanoscale materials are very important for biosensing applications as well as for understanding the unique one-dimensional carrier transport mechanism. One-dimensional semiconductor nanomaterials such as semiconductor quantum dots are extremely attractive for designing high-density protein arrays. Because of their high surfaceto-volume ratio, electro-catalytic activity as well as good biocompatibility and novel electron transport properties make them highly attractive materials for ultra-sensitive detection of biological macromolecules via bio-electronic or bio-optic devices. A genosensor or gene based biosensor is an analytical device that employs immobilized deoxyribonucleic acid (DNA) probes as the recognition element and measures specific binding processes such as the formation of deoxyribonucleic acid-deoxyribonucleic acid (DNA-DNA), deoxyribonucleic acid- ribonucleic acid (DNA-RNA) hybrids, or the interactions between proteins or ligand molecules with DNA at the sensor surface.In this thesis, I present four binary and two ternary-electrochemically and optically modulated selenide and telluride quantum dots, all synthesised at room temperature in aqueous media. Cationic gallium (Ga3+) synthesized in form of hydrated gallium perchlorate salt[Ga(ClO4)3.6H2O] from the reaction of hot perchloric acid and gallium metal was used to tailor the optical and electrochemical properties of the selenide and telluride quantum dots. The synthesized cationic gallium also allowed successful synthesis of novel water soluble and biocompatible capped gallium selenide nanocrystals and gallium telluride quantum dots. Cyclic voltammetric studies inferred that presence of gallium in a ZnSe-3MPA quantum dot lattice improved its conductivity and significantly increased the electron transfer rate in ZnTe-3MPA.Utraviolet-visible (UV-vis) studies showed that incorporation of gallium into a ZnSe-3MPA lattice resulted in a blue shift in the absorption edge of ZnSe-3MPA from 350 nm to 325 nm accompanied by decrease in particle size. An amphiphilic bifunctional molecule, 3-Mercaptopropionic acid (3-MPA) was used as a capping agent for all quantum dots. It was found that 3-MPA fully solubilised the quantum dots, made them stable, biocompatible, non agglomerated and improved their electron transfer kinetics when immobilized on gold electrodes.Retention of the capping agent on the quantum dot surface was confirmed by Fourier transform infrared spectroscopy (FTIR) which gave scissor type bending vibrations of C-H groups in the region 1365 cm-1 to 1475 cm-1, stretching vibrations of C=O at 1640 cm-1, symmetric and asymmetric vibrations of the C-H in the region 2850 cm-1 to 3000 cm-1 as well as stretching vibrations of –O-H group at 3435 cm-1. The particle size and level of non-agglomeration of the quantum dots was studied by high resolution transmission electron microscopy (HRTEM). The optical properties of the quantum dots were studied using UV-vis and fluorescence spectroscopic techniques.Quantum dot/nanocrystal modified gold electrodes were prepared by immersing thoroughly cleaned electrodes in the quantum dot/nanocrystal solution, in dark conditions for specific periods of time. The electrochemical properties of the modified electrodes were characterized by cyclic voltammetry (CV), square wave voltammetry (SWV), electrochemical impedance and spectroscopy (EIS). Six sensing platforms were then prepared using quantum dot/nanocrystal, one of which was used for detection of dopamine while the rest were used for detection of a DNA sequence related to 5-enolpyruvylshikimate-3-phosphate synthase, a common vector gene in glyphosate resistant transgenic plants.The first sensing platform, consisting of ZnSe-3MPA modified gold electrode (Au|ZnSe-3MPA) gave rise to a novel method of detecting dopamine in presence of excess uric acid and ascorbic acid. Using a potential window of 0 to 400 mV, the ZnSe-3MPA masked the potential for oxidation of uric and ascorbic acids, allowing detection of dopamine with a detection limit of 2.43 x 10-10 M (for SWV) and 5.65 x 10-10 M (for steady state amperometry), all in presence of excess uric acid (>6500 higher) and ascorbic acid (>16,000 times higher). The detection limit obtained in this sensor was much lower than the concentration of dopamine in human blood(1.31 x 10-9 M), a property that makes this sensor a potential device for detection of levels of dopamine in human blood.The other sensing platforms were prepared by bioconjugation of amine-terminated 20 base oligonucleotide probe DNA (NH2-5′-CCC ACC GGT CCT TCA TGT TC-3′) onto quantum dot modified electrodes with the aid of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). The prepared DNA electrodes were electrostatically hybridized with different sequences which included 5′-GAA CAT GAA GGA CCG GTG GG-3′ (complementary target), 5′-CATAGTTGCAGCTGCCACTG-3′ (non complementary target) and 5′-GATCATGAAGCACCGGAGGG-3′ (3-base mismatched target).The hybridization events were monitored using differential pulse voltammetry (DPV) and SWV by monitoring the guanine oxidation signal or using EIS by monitoring changes in the charge transfer resistance. The quantum dot genosensors were characterized by low detection limits (in the nanomolar range), long linear range (40 - 150 nM) and were able to discriminate among complementary, non-complementary and 3-base mismatched target sequences.

his semestral´s thesis deals with proposal and system implementation for automatic configuration of Cisco network devices. This system is called AutoConf and it is intended for distant copying configuration files from eagle-server to the switches and routers in Cisco academy laboratory. It is handled by web pages placed on eagle-server. In this system, user can create new laboratory exercises with configuration files for network devices and then these files could be used for configurations. Informations about done configurations are saved in relation database MySQL. Network devices which will be configured by system AutoConf have to be connected with eagle-server. To setup their connection settings was created decision-making mechanism. If it detects physical connection between network device and eagle-server before network device starts, it will set network device for communication with eagle-server.

Este projeto nasceu inserido num contexto de crescentes pesquisas em direção à construção de um cabedal de conhecimento acerca das ciências ambientais que tratam e estudam a dinâmica dos reservatórios de carbono e suas contribuições para o Efeito Estufa. Extrapolações de novos mapas digitalizados de solos sugerem que os espodossolos hidromórficos da Amazônia podem estar com uma contagem de carbono subestimada em até 12,3 Pg de C e trabalhos anteriores mostram que o carbono imobilizado neste perfil pode sofrer mineralização devido ao corte na rede de drenagem ou rebaixamento do nível freático, podendo assim contribuir em grande parte para o aumento de emissão dos Gases do Efeito Estufa. Nesta circunstância, coube a este trabalho, caracterizar espectroscopicamente, a matéria orgânica estocada em profundidade em 9 perfis de solo da região de São Gabriel da Cachoeira - AM, na floresta amazônica. Foram analisadas 127 amostras em quantidade de carbono e por fluorescência induzida por laser (FIL). A partir destas análises preliminares, foi possível selecionar 12 amostras de 2 perfis para análise mais detalhada através da extração das substâncias húmicas. Foram realizadas análises para obtenção da textura destes perfis, análise dos ácidos húmicos como relação C/N, espectroscopia de infravermelho com transformada de Fourier (FTIR), RMN de 13C no estado sólido, fluorescências bidimensional e tridimensional com aplicação do método estatístico análise dos fatores paralelos (PARAFAC) e também análise dos ácidos fúlvicos como carbono orgânico total (TOC), espectroscopia na região do ultra-violeta e visível e fluorescência 3D associada ao PARAFAC. Em geral, as amostras se dividiram em 3 grupos diferentes, onde a matéria orgânica em superfície se mostrou lábil e recente, a matéria orgânica nos horizontes B húmicos se mostraram com características recalcitrantes e a matéria orgânica contida nos horizontes onde existia água livre (lençol freático), se mostraram com características diferentes, indicando não serem tão jovens quanto as em superfície, porém mais jovens do que a armazenada no Bh, devido a uma possível migração por movimentos laterais do lençol freático. A correlação entre os resultados mostrou que a textura do solo é importante para o acúmulo da matéria orgânica e conseqüentemente sua humificação. Os resultados de fluorescência corroboraram a interpretação dos dados de RMN, FTIR e textura, apontando que o Perfil 4 (mais próximo ao rio) por ter C2 maior nos horizontes intermediários, contém maior quantidade de exsudatos microbianos frescos. Para o Perfil 5, que é uma mancha de Espodossolo dentro de um Latossolo e encontra-se mais longe do rio, os fluoróforos mais representativos são oriundos de anéis aromáticos mais antigos e conseqüentemente mais humificados, devido às maiores intensidades de C1 e C3. Vale ressaltar que esta interpretação se alinha com os resultados de datação do 14C desta região. Foi notório que a humificação ocorre a partir do começo do horizonte Bh e que seu acúmulo pode ocorrer tanto nos horizontes intermediários (Bh) quanto mais os profundos (úmidos). Dessa forma, pode-se concluir que uma drenagem excessiva das bordas dos rios nesta região que acumula carbono em profundidade, poderá expor a MO guardada e estocada a longo tempo, contribuindo para o aumento da temperatura global e por conseguinte catalisando um desequilíbrio no clima da sua maior reguladora no mundo: a Floresta Amazônica. / This project was born inserted in a context of increasing research towards building knowledge about environmental science that treat and study the dynamics of carbon reservoirs and their contribution to the greenhouse. Extrapolation of new digital soil maps suggests that Amazonian hydromorphic Spodosols may be with a carbon accounting underestimated by up to 12.3 Pg of C and previous work show that the carbon fixed in this profile may suffer mineralization due to the cut in the drainage network or lowering of the water level and can contribute largely to the increased emission of greenhouse gas. In this circumstance, it was instructed to this work, the spectroscopic characterization, of the stored organic matter in depth at 9 soil profiles of São Gabriel da Cachoeira - AM, in the Amazon rainforest. 127 samples were analyzed for amount of carbon and laser-induced fluorescence (LIF). From these preliminary analyzes, it was possible to select 12 samples of 2 profiles for humic substances extraction and further detailed analysis. Analyzes were conducted to obtain the texture of these profiles, analysis of humic acids as C/N ratio, Fourier Transform Infrared Spectroscopy (FTIR), solid state 13C NMR, two and three dimensional fluorescence with applying of the Parallel factors analysis (PARAFAC) statistical method and also fulvic acid analysis as Total Organic Carbon (TOC), ultra-violet and visible region spectroscopy and 3D fluorescence associated with PARAFAC. In general, the samples were divided into 3 different groups, wherein the surface organic matter evinced labile and recent. The B humic horizons organic matter proved recalcitrant characteristics and organic matter contained in horizons which had free water (groundwater), showed different characteristic, indicating they are not so young as the surface, but younger than stored in Bh, because of possible migration by lateral movements of the water table. The correlation between the results showed that soil texture is important for the accumulation of organic matter and therefore its humification. The fluorescence results confirmed the interpretation of the NMR, FTIR and texture datas, indicating that the profile 4 (closest to the river), presenting major C2 in intermediate horizons, contains larger amount of fresh microbial exudates. To profile 5, which is a Spodosol spot within a Ferrasol and is thither from the river, the most representative fluorophores came from older aromatic rings and therefore is more humified, due to higher intensities C1 and C3. It is noteworthy that this interpretation is in accord with the results of 14C dating of samples from this region. It was clear that the humification occurs from the beginning of the Bh horizon and their accumulation can occur both in the intermediate horizons (Bh) and in deeper (wet). Thus, it can be concluded that excessive drainage of the edges of rivers in this region that collects carbon in depth, may expose the OM stored for long time, contributing to increase the overall temperature and therefore catalyzing an imbalance in the climate of the biggest regulatory of it in the world: the Amazon rainforest.

Este projeto nasceu inserido num contexto de crescentes pesquisas em direção à construção de um cabedal de conhecimento acerca das ciências ambientais que tratam e estudam a dinâmica dos reservatórios de carbono e suas contribuições para o Efeito Estufa. Extrapolações de novos mapas digitalizados de solos sugerem que os espodossolos hidromórficos da Amazônia podem estar com uma contagem de carbono subestimada em até 12,3 Pg de C e trabalhos anteriores mostram que o carbono imobilizado neste perfil pode sofrer mineralização devido ao corte na rede de drenagem ou rebaixamento do nível freático, podendo assim contribuir em grande parte para o aumento de emissão dos Gases do Efeito Estufa. Nesta circunstância, coube a este trabalho, caracterizar espectroscopicamente, a matéria orgânica estocada em profundidade em 9 perfis de solo da região de São Gabriel da Cachoeira - AM, na floresta amazônica. Foram analisadas 127 amostras em quantidade de carbono e por fluorescência induzida por laser (FIL). A partir destas análises preliminares, foi possível selecionar 12 amostras de 2 perfis para análise mais detalhada através da extração das substâncias húmicas. Foram realizadas análises para obtenção da textura destes perfis, análise dos ácidos húmicos como relação C/N, espectroscopia de infravermelho com transformada de Fourier (FTIR), RMN de 13C no estado sólido, fluorescências bidimensional e tridimensional com aplicação do método estatístico análise dos fatores paralelos (PARAFAC) e também análise dos ácidos fúlvicos como carbono orgânico total (TOC), espectroscopia na região do ultra-violeta e visível e fluorescência 3D associada ao PARAFAC. Em geral, as amostras se dividiram em 3 grupos diferentes, onde a matéria orgânica em superfície se mostrou lábil e recente, a matéria orgânica nos horizontes B húmicos se mostraram com características recalcitrantes e a matéria orgânica contida nos horizontes onde existia água livre (lençol freático), se mostraram com características diferentes, indicando não serem tão jovens quanto as em superfície, porém mais jovens do que a armazenada no Bh, devido a uma possível migração por movimentos laterais do lençol freático. A correlação entre os resultados mostrou que a textura do solo é importante para o acúmulo da matéria orgânica e conseqüentemente sua humificação. Os resultados de fluorescência corroboraram a interpretação dos dados de RMN, FTIR e textura, apontando que o Perfil 4 (mais próximo ao rio) por ter C2 maior nos horizontes intermediários, contém maior quantidade de exsudatos microbianos frescos. Para o Perfil 5, que é uma mancha de Espodossolo dentro de um Latossolo e encontra-se mais longe do rio, os fluoróforos mais representativos são oriundos de anéis aromáticos mais antigos e conseqüentemente mais humificados, devido às maiores intensidades de C1 e C3. Vale ressaltar que esta interpretação se alinha com os resultados de datação do 14C desta região. Foi notório que a humificação ocorre a partir do começo do horizonte Bh e que seu acúmulo pode ocorrer tanto nos horizontes intermediários (Bh) quanto mais os profundos (úmidos). Dessa forma, pode-se concluir que uma drenagem excessiva das bordas dos rios nesta região que acumula carbono em profundidade, poderá expor a MO guardada e estocada a longo tempo, contribuindo para o aumento da temperatura global e por conseguinte catalisando um desequilíbrio no clima da sua maior reguladora no mundo: a Floresta Amazônica. / This project was born inserted in a context of increasing research towards building knowledge about environmental science that treat and study the dynamics of carbon reservoirs and their contribution to the greenhouse. Extrapolation of new digital soil maps suggests that Amazonian hydromorphic Spodosols may be with a carbon accounting underestimated by up to 12.3 Pg of C and previous work show that the carbon fixed in this profile may suffer mineralization due to the cut in the drainage network or lowering of the water level and can contribute largely to the increased emission of greenhouse gas. In this circumstance, it was instructed to this work, the spectroscopic characterization, of the stored organic matter in depth at 9 soil profiles of São Gabriel da Cachoeira - AM, in the Amazon rainforest. 127 samples were analyzed for amount of carbon and laser-induced fluorescence (LIF). From these preliminary analyzes, it was possible to select 12 samples of 2 profiles for humic substances extraction and further detailed analysis. Analyzes were conducted to obtain the texture of these profiles, analysis of humic acids as C/N ratio, Fourier Transform Infrared Spectroscopy (FTIR), solid state 13C NMR, two and three dimensional fluorescence with applying of the Parallel factors analysis (PARAFAC) statistical method and also fulvic acid analysis as Total Organic Carbon (TOC), ultra-violet and visible region spectroscopy and 3D fluorescence associated with PARAFAC. In general, the samples were divided into 3 different groups, wherein the surface organic matter evinced labile and recent. The B humic horizons organic matter proved recalcitrant characteristics and organic matter contained in horizons which had free water (groundwater), showed different characteristic, indicating they are not so young as the surface, but younger than stored in Bh, because of possible migration by lateral movements of the water table. The correlation between the results showed that soil texture is important for the accumulation of organic matter and therefore its humification. The fluorescence results confirmed the interpretation of the NMR, FTIR and texture datas, indicating that the profile 4 (closest to the river), presenting major C2 in intermediate horizons, contains larger amount of fresh microbial exudates. To profile 5, which is a Spodosol spot within a Ferrasol and is thither from the river, the most representative fluorophores came from older aromatic rings and therefore is more humified, due to higher intensities C1 and C3. It is noteworthy that this interpretation is in accord with the results of 14C dating of samples from this region. It was clear that the humification occurs from the beginning of the Bh horizon and their accumulation can occur both in the intermediate horizons (Bh) and in deeper (wet). Thus, it can be concluded that excessive drainage of the edges of rivers in this region that collects carbon in depth, may expose the OM stored for long time, contributing to increase the overall temperature and therefore catalyzing an imbalance in the climate of the biggest regulatory of it in the world: the Amazon rainforest.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第23179号 / 工博第4823号 / 新制||工||1754(附属図書館) / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 田中 宏明, 教授 清水 芳久, 講師 中田 典秀 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM