The Arctic is warming rapidly as a result of global climate change. Permafrost - permanently frozen ground - plays a critical role in shaping arctic ecosystems and stores nearly one half of the global soil organic matter. Therefore, disturbance of permafrost will likely impact the carbon and related biogeochemical processes on local and global scales. In the Alaskan Arctic, fire and thermokarst (permafrost thaw) have become more common and have been hypothesized to accelerate the hydrological export of inorganic nutrients and sediment, as well as biodegradable dissolved organic carbon (BDOC), which may alter ecosystem processes of impacted streams. The biogeochemical characteristics of two tundra streams were quantified several years after the development of gully thermokarst features. The observed responses in sediment and nutrient loading four years after gully formation were more subtle than expected, likely due to the stabilization of the features and the dynamics controlling the hydrologic connectivity between the gully and the stream. The response of impacted streams may depend on the presence of water tracks, particularly their location in reference to the thermokarst and downslope aquatic ecosystem. We found evidence of altered ecosystem structure (benthic standing stocks, algal biomass, and macroinvertebrate composition) and function (stream metabolism and nutrient uptake), which may be attributable to the previous years' allochthonous gully inputs. The patterns between the reference and impacted reaches were different for both stream sites. Rates of ecosystem production and respiration and benthic chlorophyll-a in the impacted reaches of the alluvial and peat-lined streams were significantly lower and greater, respectively, compared to the reference reaches, even though minimal differences in sediment and nutrient loading were detected. Rates of ammonium and soluble reactive phosphorus uptake were consistently lower in the impacted reach at the alluvial site. The observed differences in metabolism, nutrient uptake and macroinvertebrate community composition suggest that even though the geochemical signal diminished, gully features may have long-lasting impacts on the biological aspects of downstream ecosystem function. In a separate study, a suite of streams impacted by thermokarst and fire were sampled seasonally and spatially. Regional differences in water chemistry and BDOC were more significant than the influences of fire or thermokarst, likely due to differences in glacial age and elevation of the landscape. The streams of the older (>700 ka), lower elevation landscape contained higher concentrations of dissolved nitrogen and phosphorus and DOC and lower BDOC compared to the streams of the younger (50-200 ka) landscapes that had lower dissolved nutrient and DOC quantity of higher biodegradability. The findings in this dissertation indicate that arctic stream ecosystems are more resilient than we expected to small-scale, rapidly stabilizing gully thermokarst features and disturbance caused by fire. Scaling the results of these types of studies should consider the size of thermokarst features in relation to the size of impacted rivers and streams. It remains to be determined how general permafrost thaw will affect the structure and function of arctic streams in the future.

Soils represent an important terrestrial carbon (C) sink, storing up to three times the amount of atmospheric C, however climate and land use changes may transform soils into C sources. River corridor (RC) soils and associated C are at risk to become mobilized by erosion such as bank failure and scour events. Once soil-derived organic C is transferred into the stream, microbial processes and photodegradation of the dissolved, labile (or bioavailable) fractions can lead to the production of CO2, which can evade and increase atmospheric CO2 levels. Because predicted increases in heavy precipitation will likely increase this type of riverine erosion, it is important to better understand the potential for the release of bioavailable C from RCs. One objective of this thesis was therefore to identify and characterize representative samples of soils from a typical Vermont RC for common land covers and simulate the production of dissolved organic matter (DOM) during riverine soil erosion. Field sites representative of typical agricultural and forested land uses were selected based on the analysis of 106 existing samples and resampled multiple times over the summer of 2015. Production of DOM from riverine erosion was simulated using aqueous soil extracts (ASE), where soil and water were shaken at fixed ratios followed by the separation of the extract. To study the characteristics of these extracts (which serve as analogue of stream water after erosion), water extractable C (WEOC) concentrations, water extractable nitrogen, fluorescence properties of DOM, and bioavailability were determined. Results indicated a common, dominantly terrestrial source material for all land covers, but C concentrations and fluorescence properties differed. High but variable amounts of soil organic C and WEOC were observed in agricultural riparian and agricultural stream bank samples, and lower concentrations in agricultural field, forest, forest riparian, and forest stream banks. WEOC bioavailability was high in all agricultural land covers and low in forested land covers. Because this study is the first in which ASE are used as analogues for stream water after riverine erosion, a second objective was to test laboratory methods used in this study for their effect on WEOC, fluorescence properties, and bioavailability. Specifically, the effects of soil drying, soil storage, and the effects of the extraction solution were tested. For this, ASE were prepared from soils that were field moist, dried, and after two years of storage. In addition, dried soils were extracted using different solutions including a salt solution, river water, and double deionized (DDI) water. Results indicated WEOC concentration and microbial humic-like fluorescence from extracts of dried soils were higher than those in extracts of field moist soils, while WEOC concentration and microbial humic-like fluorescence was highest in extracts of soils stored long term. In addition, the bioavailability of WEOC was higher in dried soils than field moist soils. The extraction solutions of DDI water and river water produced DOM with similar fluorescence properties, while the salt solution extracted a different, less humified pool of C. Overall, the ASE methods used in this study are effective in simulating stream bank erosion and subsequent C release into stream water, however the effects of drying the soils need to be considered when assessing DOM.

Planting trees on agricultural land either as farm woodlands or agroforestry (trees integrated with farming) is one option for reducing the level of atmospheric carbon dioxide. Trees store carbon as biomass, and may increase carbon storage in the ground. A review of the literature outlined uncertainty relating to changes in carbon storage after planting trees on agricultural land. The aim of this thesis is to deter¬mine the impact of tree planting on arable and pasture land in terms of above and belowground carbon storage and thereby address these uncertainties, and assess the implications for the Woodland Carbon Code: a voluntary standard for carbon storage in UK woodlands. Measurements of soil organic carbon to a depth of 1.5 m were taken at two field sites in Bedfordshire in the UK: a 19 year old silvoarable trial, and a 14 year old silvopasture and farm woodland. On average 60% and 40% of the soil carbon (rel¬ative to 1.5 m) was found beneath 0.2 and 0.4 m in depth respectively. Whilst tree planting in the arable system showed gains in soil organic carbon (12.4 t C ha−1 at 0–40 cm), tree planting in the pasture was associated with losses of soil organic carbon (6.1–13.4 t C ha−1 at 0–10 cm). Evidence from a nearby mature grazed woodland indicate that these losses may be recovered. No differences associated with tree planting were found to the full 1.5 m, though this may be due to a lack of statistical power. Measurements of above and belowground biomass, and the root distribution of 19 year old poplar (Populus spp.) trees (at the silvoarable trial) and ash (Fraxinus excelsior) trees ranging from 7 to 21 years (at several field sites across Bedfordshire) were made, involving the destructive harvest of 48 trees. These measurements suggest that Forestry Commission yield tables overestimate yield for poplar trees grown in a silvoarable system. An allometric relationship for determining ash tree biomass from diameter measurements was established. The biophysical model Yield-SAFE was updated to take into account root growth, and was parameterised using field measurements. It was successfully used to describe existing tree growth at two sites, and was then used to predict future biomass carbon storage at the silvoarable trial. Measurements indicate that losses in soil carbon at relatively shallow depths can offset a large proportion of the carbon stored in tree biomass, but assessing changes on a site by site basis may be prohibitively expensive for schemes such as the Woodland Carbon Code.

In rivers, association of organic contaminants with dissolved organic carbon may limit freely dissolved or bioavailable fractions and toxicity of organic contaminants. Consequently, assessment of toxicity of organic contaminants on the basis of their total chemical concentrations may lead to overestimation of risks to organic contaminants. Therefore, to achieve reliable and accurate risks assessment for organic contaminants, determination of bioavailability is important. The influence of humic acid on the bioavailability of organic contaminants in rivers was studied, using three chemicals with different properties as model contaminants, which at the start of the study were detected in wastewater effluents. It was hypothesized that in the presence of dissolved organic carbon, a fraction of the total concentration of an organic contaminant would not be bioavailable in river water. Therefore, the aim of the study was to determine bioavailability and its impact on toxicity. Bioavailability in the presence of humic acid was determined chemically and using a yeast estrogen screen assay. The chemical method comprised solid-phase extraction and liquid chromatography-mass spectrometry to determine freely dissolved and the fraction of the chemicals associated with dissolved organic carbon. The results indicated increased binding to dissolved organic carbon with the hydrophobicity of the test compounds except for perfluorooctane sulfonate. The dissolved organic carbon-water partition coefficient for ethinylestradiol was determined to be Log KDOC 2.36. Log KDOC values of 4.15 and 4.41 at 10 and 100 mg/L humic acid, respectively, were derived for hexabromocyclododecane indicating greater binding than ethinylestradiol due to the more hydrophobic character. The yeast estrogen screen was used as a biological method to measure the effect of humic acid on the bioavailability of ethinylestradiol and a more hydrophobic compound, dichlorodiphenyltrichloroethane. Results of the yeast estrogen screen indicated that the presence of humic acid had no effect on bioavailability of either of the chemicals.

This thesis provides an overview of mercury distribution in the forest soils located in vicinity of historical and current mercury emission sources. The sites were chosen around Bohemian Karst due to presence of emission source, i.e. iron production processes, cement plants, lime processing plants. The chosen sites were near municipalities of Králův Dvůr, Radotín and Hrádek u Rokycan. From these sites the soils samples were collected from organic and mineral horizons. Average mercury concentration in organic horizons was 288 µg.kg-1, organo-mineral horizons A contained 241 µg.kg-1, anthropogenic horizons M 287 µg.kg-1 and horizons B 56 µg.kg-1 only. The relations among mercury and soil components were tested. Strong link between mercury, soil organic matter (SOM) and sulfur was found. The result indicated that the origin of mercury in soil samples was atmospheric deposition rather than bedrock. High concentrations of oxalate extractable aluminum, iron and manganese in mineral horizons have been explained as the cause of bedrock weathering. Powered by TCPDF (www.tcpdf.org)

O hidrogênio (H2) produzido a partir de microrganismos fotossintetizantes (microalgas e cianobactérias) é considerado um vetor energético sustentável do ponto de vista ambiental. Quando comparado a outras formas de produção são encontradas limitações técnicas e econômicas principalmente pela geração de pequenos volumes de gás e pela inexistência de um ciclo de vida completo que assegure a produção contínua de H2 por esses organismos. Nesse sentido, o presente projeto teve por propósito avaliar a capacidade de produção de H2, sob condições mixotróficas, em três estirpes de cianobactérias: Anabaena sp. UTEX 1448, Anabaena sp. PCC7120 (selvagem) e Anabaena sp. PCC 7120 &Delta;hypF (mutante). O primeiro capítulo tratou da otimização de biomassa da estirpe UTEX 1448, utilizando meio de cultura BG-11 (Rippka, 1979), em condições controladas de pH (10,2), temperatura (32 ºC), radiação (30 &micro;mol.m-2.s-1), com cinco diferentes substratos orgânicos (ácido lático, glicerol, glicose, frutose e sacarose), em três concentrações de carbono (0,20; 0,52 e 0,84 gC.L-1). No segundo capítulo, investigou-se a produção de H2, pelas enzimas hidrogenase bidirecional, de assimilação e nitrogenase, com medições in vivo, a partir do uso do eletrodo de H2 (Hansatech, Ltd) e análises de clorofila a, proteínas (Western Immunoblotting) e géis de poliacrilamida desnaturantes. Os ensaios de H2 foram realizados para as três estirpes, em triplicata, com réplicas biológicas nos dias 0h, 24h, 48h, 72h e 7 dias, após passagem das culturas de condições não fixadoras de nitrogênio para condições fixadoras de H2, considerando a condição otimizada encontrada no Capítulo 1. Utilizou-se BG-11 para aumento da densidade celular em níveis que viabilizassem a realização dos ensaios e BG-110 (sem nitrato) para estímulo à diferenciação celular em heterocistos, estrutura importante por conter a enzima nitrogenase, diretamente relacionada à geração de H2. A fonte de carbono orgânico frutose a 0,84 gC.L-1 foi a condição otimizada encontrada, com produtividade de biomassa de 190 ± 18 mg.L-1.dia-1 (Anova, Tukey, p < 0,05). A estirpe mutante não cresceu nas condições otimizadas do cultivo e consequentemente não foi possível quantificar a geração de H2. Em fase clara, aos 7 dias, a maior produtividade de H2 foi de 0,50 ± 0,38 &micro;molH2.mg clorofila a-1.h-1 para a cepa PCC 7120 (selvagem) e na fase escura obteve-se produtividade média de H2 de 0,147 ± 0,00 &micro;molH2.mg clorofila a-1.h-1, ao dia 0 (0h) para a estirpe UTEX 1448. / Hydrogen (H2) produced from photosynthetic microorganisms (microalgae and cyanobacteria) is considered an environmentally sustainable energy vector. When compared to other production ways, some technical and economic limitations are found mainly because of the small amount of gas generated and also due the lack of a complete life cycle that assures the constant generation of hydrogen by these organisms. Regarding to this, the following study intended to evaluate the capacity of hydrogen production under mixotrophic conditions in three cyanobacteria strains: Anabaena sp. UTEX 1448, Anabaena sp. PCC7120 (wild type) and Anabaena sp. PCC 7120 &Delta;hypF (mutant). The first chapter refers to the optimization of the biomass of the UTEX1448 strain, using BG-11 as a mean of culture (Rippka, 1979) under controlled conditions of pH (10,2), radiation (30 &micro;mol.m-2.s-1), temperature (32ºC), with no photoperiod, five different organic substrates (lactic acid, glycerol, glucose, fructose and sucrose) in three different carbon concentrations (0.20, 0.52 and 0.84 gC.L-1). The second chapter investigated the hydrogen production by the bidirectional hydrogenases enzymes, by uptake and nitrogenase, with in vivo measurements using the hydrogen electrode (Hansatech, Ltd), chlorophyll a and proteins analyses (Western Immunoblotting and SDS-Polyacrylamide gels). The H2 assays were performed for the three strains, in triplicate, with biological replicates on days 0h, 24h, 48h, 72h and 7 days, considering the optimized condition found in Chapter 1. BG-11 medium was used to increase cell density at levels that would be viable to perform the tests and BG-110 (without nitrate) to stimulate cell differentiation in heterocysts, an important structure that contains the nitrogenase enzyme, directly related to H2 generation. The source of organic carbon fructose at 0.84 gC.L-1 was the optimized condition found, with biomass productivity of 190 ± 18 mg.L-1.day-1 (ANOVA, Tukey, p < 0.05). The mutant strain did not grow under optimized culture conditions and consequently it was not possible to quantify H2 generation. In the light phase, at 7 days, the highest yield of hydrogen was 0.50 ± 0.38 &micro;molH2.mg chlorophyll a-1.h-1 for the strain PCC 7120 (wild) and in the dark phase yielded average productivity of hydrogen from 0.147 ± 0 &micro;molH2.mg chlorophyll a-1.h-1, at day 0 (0h) for strain UTEX 1448.

Radiofármacos são preparações farmacêuticas que possuem um radionuclídeo em sua composição. Cerca de 95% deles são utilizados com finalidade diagnóstica e em sua maioria são administrados por via parenteral, requerendo o uso de água purificada (AP) e para injeção (API) nos processos de produção, controle de qualidade e pesquisa de novos radiofármacos. A produção de radiofármacos no Brasil deve atender às Boas Práticas de Fabricação (BPF), RDC n. 17/2010 e RDC n. 63/2009 da ANVISA e requisitos de qualidade definidos pelas farmacopeias vigentes. Considerando que os volumes dos lotes de fabricação de radiofármacos são reduzidos, de algumas dezenas a centenas de mililitros, e a sua validade é de algumas horas a alguns dias, frequentemente tem sido utilizados sistemas purificadores de uso laboratorial para a produção de AP e API nas radiofarmácias. A determinação de carbono orgânico total (COT) é um dos requisitos a serem atendidos na avaliação da qualidade de AP e API e o seu limite é de 500 &mu;g L-1. O objetivo deste estudo foi validar o método analítico de COT que combina reações de acidificação e de oxidação química do carbono para análise de carbono inorgânico (CI) e carbono total (CT), na análise de AP e API, avaliar o desempenho de sistemas de purificação de uso laboratorial para a produção de AP e API e comparar com a API adquirida de fornecedores externos. Utilizou-se um analisador de carbono modelo TOC-Vwp acoplado a um amostrador automático modelo ASI-V, ambos da marca Shimadzu® e controlados por software TOC Control-V e frascos de 40 mL lavados com HNO3 15%, com soluções de reagente oxidante (Na2S2O8 0,5 mol L-1) e acidificante (H3PO4 3,0 mol L-1), soluções de COT/CT (C8H5O4K) e CI (Na2CO3 e NaHCO3) nas concentrações 100-1000 &mu;g L-1. Foram avaliados os parâmetros de validação de método: conformidade do sistema, robustez, repetibilidade, precisão intermediária, exatidão, linearidade e limites de detecção e quantificação. O desempenho de 5 sistemas de purificação foram avaliados, com amostragem de AP e API de 6 pontos (3 de AP e 3 de API) e foram analisados COT, condutividade, pH, contagem de aeróbios totais e endotoxina bacteriana (somente para API). As melhores condições de análise foram 2 mL de oxidante, 3% de acidificante, tempo de integração da curva de CT de 10 minutos e 3 minutos para CI. As curvas analíticas de CT e CI foram lineares nas faixas de concentrações analisadas, com a soma residual dos mínimos quadrados (r2) maior que 0,997. Os resultados de repetibilidade apresentaram valores entre 0,40 4,40%, a precisão intermediária por sua vez apresentou a seguinte variação, 0,65 a 4,63% e exatidão apresentou valores na faixa de 96,76-112,52%. Os limites de detecção (LD) e quantificação (LQ) foram 31,83 e 106,11 &mu;g L-1 e 59,16 e 197,22 &mu;g L-1, para CT e CI, respectivamente. A avaliação de desempenho dos purificadores indicam que um procedimento adequado de limpeza do reservatório de água é importante para manter a concentração de COT em cerca de 100 &mu;g L-1. A análise de COT/CI pode ser utilizada como indicador da necessidade de manutenção do sistema purificador. Algumas API embaladas apresentaram COT acima de 500 &mu;g L-1. O monitoramento de COT durante a avaliação de desempenho dos sistemas de uso laboratorial acoplados a reservatórios indicou que eles são equipamentos adequados para obtenção de AP e API em radiofarmácia. / Radiopharmaceuticals are pharmaceutical preparations that have one radionuclide in their composition. About 95% of them are used with diagnostic purposes and most of them are parenterally administered, requiring the use of purified water (PW) and water for injection (WFI) in the production process, quality control and research of new radiopharmaceuticals. The production of radiopharmaceuticals in Brazil must comply with Good Manufacturing Practices (GMP), RDC n. 17/2010 and RDC n. 63/2009 from ANVISA, and the requirements defined by current pharmacopoeias. Considering that the batch volumes of the radiopharmaceuticals are reduced, up to some milliliters, and the shelf lives are from hours to a few days, purification systems for laboratory use have often been used to produce PW and WFI in the radiopharmacies. The determination of Total Organic Carbon (TOC) is one of the requirements for the assessment of PW and WFI and its limit is 500 &mu;g L-1. The aim of this study was to validate the analytical method for TOC analysis that combines acidification and chemical oxidation to quantify inorganic carbon (IC) and total carbon (TC) in the analysis of PW and WFI; to evaluate the performance of purification systems for laboratorial use to produce PW and WFI and to compare with WFI acquired from external suppliers. It was used a carbon analyzer model TOC-Vwp coupled to an autosampler model ASI-V, both from Shimadzu® controlled by TOC-V Control software and 40 mL vials washed with 15% HNO3, an oxidizing reagent (Na2S2O8 0.5 mol L-1), an acid reagent (H3PO4 3.0 mol L-1), TOC/TC (C8H5O4K) and IC (Na2CO3 and NaHCO3) solutions in the range of 0 - 1000 &mu;g L-1. The evaluated validation parameters were system suitability, robustness, repeatability, intermediate precision, accuracy, linearity and detection and quantification limits. The performance of 5 purification systems were evaluated by sampling PW and WFI from 6 places (3 were PW and 3 WFI) and TOC, conductivity, pH, total aerobic count and bacterial endotoxin (API only) were analyzed. The best conditions of analysis were 2.0 mL oxidizing reagent, 3% acid reagent, 10 minutes integration curve time for TC and 3 minutes for IC. The TC and IC analytical curves were linear in the evaluated range, with residual sum of minimum squares (r2) greater than 0.997. The results of repeatability were from 0.40 to 4.40%, intermediate precision were from 0.65 to 4.63%, and accuracy were in the range of 96.76 to 112.52%. The detection limit (DL) and quantification limit (QL) were 31.83 and 106.11 &mu;g L-1 and 59.16 and 197.22 &mu;g L-1 for IC and TC, respectively. The evaluation of the performance of the water purification system indicated that an adequate procedure for cleaning of the storage tank is important to maintain TOC concentration about 100 &mu;g L-1. TOC /IC analysis can be used as an indicator of the need for maintenance of the purification system. Some commercial packed WFI presented TOC above 500 &mu;g L-1. The TOC monitoring during evaluation of the performance of purification systems for laboratory use coupled with storage tank indicated that they are suitable equipment for obtaining PW and WFI in radiopharmacies.

Compreender os ciclos de nutrientes e a dinâmica da matéria orgânica no ecossistema da Amazônia é essencial para o domínio do manejo eficiente da floresta e do solo. O desaparecimento de florestas tropicais, acompanhada de acelerados processos de perda de solo e de matéria orgânica, pelo desmatamento, queimadas e avanço da fronteira agrícola despertam preocupações. As características das substâncias húmicas remetem aos processos de gênese da matéria orgânica, à capacidade de sustentabilidade para os usos múltiplos em cultivos e aparece como indicador da qualidade do solo. O objetivo deste trabalho foi relacionar as características das substâncias húmicas do solo com o seqüestro de carbono em sítios de floresta em clímax, em área moderadamente e intensamente antropizada, ambientes de influência da Rodovia BR-163 - Cuiabá-Santarém, região que experimenta um incremento das ações antrópicas em função do anúncio da pavimentação desta rodovia. Foram determinadas as características das substâncias húmicas pelas técnicas de espectroscopia no infravermelho com transformada de Fourier (FTIR), análise elementar, espectroscopia de fluorescência de luz no UV/Visível, espectroscopia de absorção de luz no UV/Visível, espectroscopia de ressonância magnética nuclear (RMN) e espectroscopia de ressonância paramagnética eletrônica nuclear (EPR). Os resultados de infravermelho das substâncias húmicas do solo do sítio de floresta em clímax, indicam alta complexidade no arranjo conformacional, denotando-se a presença de elevada humificação do material orgânico, o que é corroborado pelos resultados de fluorescência, onde as características das substâncias húmicas deste ambiente apresentaram maior policondensação e grau de humificação. Utilizando-se a espectroscopia de absorção de luz no UV/Visível, constatou-se que a razão E4/E6 é de 2,27 para solo do ambiente de floresta em clímax. Esse é o menor valor das três frações, o que demonstra que as substâncias húmicas deste sítio estão em estágio elevado de policondensação e apresentam maior quantidade de estruturas aromáticas. Os resultados de RMN indicam que a maior percentagem de carbono aromático está exatamente nas substâncias húmicas do solo do sítio de floresta em clímax. Os resultados de EPR demonstram também que as substâncias húmicas dos solos dos sítios em clímax apresentam maiores números de radicais livres do tipo semiquinona (7,52) dos três ambientes estudados. As substâncias húmicas provenientes dos solos dos sítios com intensa atividade antrópica indicam a presença de menor grau de humificação, pelo número de radicais livres do tipo semiquinona (4,68), menor valor dos três ambientes estudados. Desta forma, as características das substâncias húmicas do solo de ambientes em clímax, pela elevada aromaticidade, policondensação e grau de humificação, proporcionam aumento da biodiversidade, incremento da produtividade, melhoria da estrutura deste solo, contribuindo junto à formação de fração húmica não lábil, bem como maior estabilidade dos complexos organominerais, condições favoráveis para o seqüestro de carbono e mitigação do aumento do efeito estufa. / Understanding the cycles of nutrients and organic matter dynamics in Amazons ecosystem is essential for the domain of efficient management of the forest and soil. The disappearance of tropical forests, accompanied by processes of accelerated loss of soil and organic matter, for the deforestation, forest fires and advancement of agricultural frontier arouse concerns. The characteristics of humic substances refer processes of genesis organic matter, capacity of sustainability for multiple uses in cultures appears as indicator the quality of the organic matter. The objective of this work was to relate the characteristics of humics substances in the soil, with the carbon sequestration in sites of forest in climax, in moderately and intensely area in humans use, environments in Influence of highway BR-163 - Cuiaba-Santarem, a region experiencing an increase in action of the human being according to the announcement of paving the road. There were certain characteristics of humic substances by the Fourier transform infrared (FTIR) spectroscopy, elemental analysis, ultraviolet-visible fluorescence spectroscopy, ultraviolet-visible absorption spectroscopy, nuclear magnetic resonance (NMR) spectroscopy and electronic paramagnetic resonance (EPR) spectroscopy. The results of infrared of humic substances in soil site of a climax forest, show high complexity in conformal arrangement, showing up the presence of high humification of organic material, which is corroborated by the results of fluorescence, where the characteristics of humic substances this environment polycondensation and had greater degree of humification. Using ultraviolet-visible absorption spectroscopy, it was found that the reason E4/E6 is 2.27 for the environment of forest in climax. This is the lowest of the three fractions, which shows that the humic substances from this site are in high stage of polycondensation and the greatest amount of aromatic structures. The results of NMR indicate that the highest percentage of carbon aromatic is exactly humic substances in soil from site of forest in climax. The results of EPR also demonstrate that the soil humic substances in climax\'s sites show the highest numbers of free radicals semiquinonas type (7.52) in the three kinds of environments studied. The humic substances from the soil of sites with intense human activity indicate the lesser presence of degree humification, for the number of free radicals semiquinona\'s type (4.68), lower value of the three environments studied. Thus, the characteristics of humic substances in soil from environments in the climax for the high aromaticity, polycondensation and degree of humification, provide an increase of biodiversity, increasing productivity, improving the structure of the soil, contributing next to the formation of humic fraction not labile, greater stability of organic minerals complexes, favourable conditions for carbon sequestration and mitigation of increased greenhouse effect.

Resumo: O sequestro de carbono nos ambientes terrestres, sendo feito de forma natural pelos vegetais através da fotossíntese, cujo processo permite fixar o carbono nos solos e, em forma de matéria lenhosa nas plantas, vem sendo apontado como uma alternativa mitigadora das mudanças climáticas, segundo acordos internacionais como o Protocolo de Kyoto. A retirada da floresta nativa provoca a diminuição significativa da biomassa microbiana e da fertilidade do solo. A reserva de carbono na matéria orgânica do solo é uma importante estratégia para atenuar a concentração de CO2 na atmosfera. Com o reflorestamento dessas áreas ocorre uma recuperação lenta e contínua da quantidade e qualidade da matéria orgânica. O eucalipto é a essência florestal mais plantada no Brasil e essas plantações florestais com eucalipto poderão cumprir o papel de aumentar as concentrações de carbono orgânico no solo, recuperando estruturas perdidas quando da exportação da madeira através da colheita, bem como, provocando mudanças ambientais associadas. Este trabalho objetivou quantificar a fixação de carbono no compartimento do solo de 0 a 60 cm de uma floresta nativa em comparação com plantios de eucalipto com 3 diferentes idades: 0 a 1 ano (área recém implantada); 3 a 4 anos (metade do ciclo) e 6 a 7 anos (época de corte). Foram escolhidos quatro diferentes sítios de amostragem com uma área amostral de 1 ha cada. Foram coletadas amostras de solo no inverno e no verão a diferentes profundidades para que se pudesse conhecer a quantidade de carbono orgânico fixado ao longo do perfil do solo considerando o fator da sazonalidade. Os resultados indicam que o manejo nas áreas interferiu no acúmulo de carbono no solo dos quatro sítios estudados, mostrando também que o fragmento de Cerrado estoca menos carbono que os plantios de eucalipto. Quanto à sazonalidade, houve diferença significativa... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The carbon sequestration in terrestrial environments, by plants through photosynthesis, allows carbon fixing as a woody matter in plants. This process has been identified as an alternative to mitigate climate change, according to Kyoto Protocol, an international environmental agreement. The removal of the native forest causes a significant decrease of microbial biomass and soil fertility. The storage of carbon in soil organic matter is an important strategy to reduce the concentration of CO2 in the atmosphere. With the reforestation of these areas, occurs a slow and continuous recovery of the quantity and quality of organic matter. The eucalyptus is the most planted species in Brazil for industrial supply. These eucalyptus reforestations may fulfill the role of increasing soil organic carbon concentration, recovering some structures lost by wood harvesting and causing associated environmental changes. This study aimed to quantify the carbon fixation within the soil compartment from 0 to 60 cm depth of a native forest formation in comparison with eucalyptus plantations with 3 different ages: 0 to 1 year (newly planted area); 3 to 4 years (half the harvesting cycle) and 6 to 7 years (harvesting time). Four different sites were chosen for sampling, with a sampling area of 1 ha each. Soil samples were collected in winter and summer time, at different depths, to quantify the organic carbon fixed throughout the soil profile, considering the seasonality factor. The results indicate that management in each area interfered in the accumulation of carbon in the soil in the four sites studied. The savanna fragment stored less carbon than the eucalyptus plantations. Regarding seasonality, a significant difference was found between the accumulation of carbon in winter and summer... (Complete abstract click electronic access below) / Orientador: Iraê Amaral Guerrini / Coorientador: Vera Lex Engel / Banca: Dirceu Maximino Fernandes / Banca: Jacob Siva Souto / Mestre

Radiofármacos são preparações farmacêuticas que possuem um radionuclídeo em sua composição. Cerca de 95% deles são utilizados com finalidade diagnóstica e em sua maioria são administrados por via parenteral, requerendo o uso de água purificada (AP) e para injeção (API) nos processos de produção, controle de qualidade e pesquisa de novos radiofármacos. A produção de radiofármacos no Brasil deve atender às Boas Práticas de Fabricação (BPF), RDC n. 17/2010 e RDC n. 63/2009 da ANVISA e requisitos de qualidade definidos pelas farmacopeias vigentes. Considerando que os volumes dos lotes de fabricação de radiofármacos são reduzidos, de algumas dezenas a centenas de mililitros, e a sua validade é de algumas horas a alguns dias, frequentemente tem sido utilizados sistemas purificadores de uso laboratorial para a produção de AP e API nas radiofarmácias. A determinação de carbono orgânico total (COT) é um dos requisitos a serem atendidos na avaliação da qualidade de AP e API e o seu limite é de 500 &mu;g L-1. O objetivo deste estudo foi validar o método analítico de COT que combina reações de acidificação e de oxidação química do carbono para análise de carbono inorgânico (CI) e carbono total (CT), na análise de AP e API, avaliar o desempenho de sistemas de purificação de uso laboratorial para a produção de AP e API e comparar com a API adquirida de fornecedores externos. Utilizou-se um analisador de carbono modelo TOC-Vwp acoplado a um amostrador automático modelo ASI-V, ambos da marca Shimadzu® e controlados por software TOC Control-V e frascos de 40 mL lavados com HNO3 15%, com soluções de reagente oxidante (Na2S2O8 0,5 mol L-1) e acidificante (H3PO4 3,0 mol L-1), soluções de COT/CT (C8H5O4K) e CI (Na2CO3 e NaHCO3) nas concentrações 100-1000 &mu;g L-1. Foram avaliados os parâmetros de validação de método: conformidade do sistema, robustez, repetibilidade, precisão intermediária, exatidão, linearidade e limites de detecção e quantificação. O desempenho de 5 sistemas de purificação foram avaliados, com amostragem de AP e API de 6 pontos (3 de AP e 3 de API) e foram analisados COT, condutividade, pH, contagem de aeróbios totais e endotoxina bacteriana (somente para API). As melhores condições de análise foram 2 mL de oxidante, 3% de acidificante, tempo de integração da curva de CT de 10 minutos e 3 minutos para CI. As curvas analíticas de CT e CI foram lineares nas faixas de concentrações analisadas, com a soma residual dos mínimos quadrados (r2) maior que 0,997. Os resultados de repetibilidade apresentaram valores entre 0,40 4,40%, a precisão intermediária por sua vez apresentou a seguinte variação, 0,65 a 4,63% e exatidão apresentou valores na faixa de 96,76-112,52%. Os limites de detecção (LD) e quantificação (LQ) foram 31,83 e 106,11 &mu;g L-1 e 59,16 e 197,22 &mu;g L-1, para CT e CI, respectivamente. A avaliação de desempenho dos purificadores indicam que um procedimento adequado de limpeza do reservatório de água é importante para manter a concentração de COT em cerca de 100 &mu;g L-1. A análise de COT/CI pode ser utilizada como indicador da necessidade de manutenção do sistema purificador. Algumas API embaladas apresentaram COT acima de 500 &mu;g L-1. O monitoramento de COT durante a avaliação de desempenho dos sistemas de uso laboratorial acoplados a reservatórios indicou que eles são equipamentos adequados para obtenção de AP e API em radiofarmácia. / Radiopharmaceuticals are pharmaceutical preparations that have one radionuclide in their composition. About 95% of them are used with diagnostic purposes and most of them are parenterally administered, requiring the use of purified water (PW) and water for injection (WFI) in the production process, quality control and research of new radiopharmaceuticals. The production of radiopharmaceuticals in Brazil must comply with Good Manufacturing Practices (GMP), RDC n. 17/2010 and RDC n. 63/2009 from ANVISA, and the requirements defined by current pharmacopoeias. Considering that the batch volumes of the radiopharmaceuticals are reduced, up to some milliliters, and the shelf lives are from hours to a few days, purification systems for laboratory use have often been used to produce PW and WFI in the radiopharmacies. The determination of Total Organic Carbon (TOC) is one of the requirements for the assessment of PW and WFI and its limit is 500 &mu;g L-1. The aim of this study was to validate the analytical method for TOC analysis that combines acidification and chemical oxidation to quantify inorganic carbon (IC) and total carbon (TC) in the analysis of PW and WFI; to evaluate the performance of purification systems for laboratorial use to produce PW and WFI and to compare with WFI acquired from external suppliers. It was used a carbon analyzer model TOC-Vwp coupled to an autosampler model ASI-V, both from Shimadzu® controlled by TOC-V Control software and 40 mL vials washed with 15% HNO3, an oxidizing reagent (Na2S2O8 0.5 mol L-1), an acid reagent (H3PO4 3.0 mol L-1), TOC/TC (C8H5O4K) and IC (Na2CO3 and NaHCO3) solutions in the range of 0 - 1000 &mu;g L-1. The evaluated validation parameters were system suitability, robustness, repeatability, intermediate precision, accuracy, linearity and detection and quantification limits. The performance of 5 purification systems were evaluated by sampling PW and WFI from 6 places (3 were PW and 3 WFI) and TOC, conductivity, pH, total aerobic count and bacterial endotoxin (API only) were analyzed. The best conditions of analysis were 2.0 mL oxidizing reagent, 3% acid reagent, 10 minutes integration curve time for TC and 3 minutes for IC. The TC and IC analytical curves were linear in the evaluated range, with residual sum of minimum squares (r2) greater than 0.997. The results of repeatability were from 0.40 to 4.40%, intermediate precision were from 0.65 to 4.63%, and accuracy were in the range of 96.76 to 112.52%. The detection limit (DL) and quantification limit (QL) were 31.83 and 106.11 &mu;g L-1 and 59.16 and 197.22 &mu;g L-1 for IC and TC, respectively. The evaluation of the performance of the water purification system indicated that an adequate procedure for cleaning of the storage tank is important to maintain TOC concentration about 100 &mu;g L-1. TOC /IC analysis can be used as an indicator of the need for maintenance of the purification system. Some commercial packed WFI presented TOC above 500 &mu;g L-1. The TOC monitoring during evaluation of the performance of purification systems for laboratory use coupled with storage tank indicated that they are suitable equipment for obtaining PW and WFI in radiopharmacies.