Quantitative soil ingestion studies employing a mass balance tracer approach have been used to determine soil ingestion rate for use in human health risk assessments (HHRAs). Past studies have focused on soil ingestion in populations living in urban/suburban environments and the results have been highly variable. Moreover, there is a paucity of reliable quantitative soil ingestion data to support human health risk assessments of other lifestyles that may be predisposed to ingesting soil, such as indigenous populations following traditional lifestyles. Thus, the primary objective of the research was to determine if populations following lifestyles typical of traditional land use practices in rural or wilderness areas ingest more soil than populations living in urban or suburban environments. Further, the research investigated the use of alternative mass balance tracers, specifically isotopes of the 238U and 232Th decay series, to reduce soil ingestion estimate variability. Mass balance tracer methods were developed and validated in a pilot canine study, and methods using isotope tracers were adapted to permit quantification of sediment ingestion in the benthic fish Moxostoma macrolepidotum (Shorthead Redhorse Sucker). A pilot human soil ingestion study of 7 subjects from an Aboriginal community in British Columbia was conducted over a 3-week period. The mean soil ingestion rate calculated using the daily means of the 4 elemental tracers with the lowest food-to-soil ratios (i.e., Al, Ce, La, Si) was observed to be approximately 74 mg d-1 (standard deviation 91 mg d-1), The median soil ingestion rate was 60 mg d-1, and the 90th percentile was 196 mg d-1. These soil ingestion rate estimates are higher than those currently recommended for HHRAs of adults, and higher than those obtained in most previous studies of adults. However, the estimates are much lower than the earlier qualitative assessments for subsistence lifestyles (i.e., 330-400 mg d-1). The study results also demonstrated that isotopes of the 238U and 232Th decay series radionuclide are not reliable mass balance tracers for estimating soil ingestion in humans; however, they may be useful for quantifying soil and sediment ingestion in wildlife.

Mass, solute (chloride), isotope (deuterium) and thermal balances were completed at Perry Lakes, two semi-permanent 'water table' lakes near Perth, Western Australia. All balance components except groundwater discharge/recharge were measured independently. These difficult to measure groundwater components of lake-aquifer interaction were estimated by integrating mass, solute and chloride data in sequential 4 day balances spanning two years. Before urbanisation, such wetlands functioned predominantly as flow-through lakes. Now, large winter storm water inputs (and summer artificial level maintenance pumped locally from groundwater) dominate. In East Lake these inputs together comprise 42% of the annual water budget; groundwater discharge is reduced to just 2%. Even under flow-through conditions, these 'non natural' inputs are so large East Lake always tends towards a recharge state and commonly becomes a local groundwater mound. Flow-through is established in both lakes over winter. Initially each lake functions separately however as winter progresses shared capture and release zones are established. Maintenance of lake levels in early summer forces East Lake back to recharge status. Sediment heat flux (Qse) is significant in these very shallow lakes. Over summer Qse was negative, with a net movement of heat from the water into the sediments which act as a seasonal heat sink. In winter Qse was positive and stored summer heat was returned to the water column. This flux at times exceeded 40 W m-2. Evaporation was determined independently by floating pan, leaving Qse as the thermal balance residual. Ignoring Qse, annual evaporation determined by thermal balance was over estimated by 7%. Over and under estimates of individual 12 day balance period evaporation exceeded 50%. Monthly Class A (Perth airport) pan coefficients varied from 0.54 (January) to 0.86 (September). Ten empirical equations for evaporation were calibrated and compared with the East Lake floating pan. Best performer was the Makkink which tracked the floating pan closely throughout all seasons. Poorest were the Penman, DeBruin-Keijman, Priestly-Taylor and Brutsaert-Stricker which grossly over estimated late winter evaporation. Transpiration from Typha orientalis, estimated using hydrograph techniques was 43% of open water evaporation in summer and 28% annually. Temperature controlled evaporation pans (tracking lake temperature) experimentally determined the local deuterium content of lake evaporate ƒÔE, required for isotopic balances. Techniques employing pans evaporated to dryness and pans evaporated at constant volume were run in tandem continuously for two years. This study singularly integrates mass, solute and isotope balances thereby allowing groundwater components to be accurately quantified. The isotope balances are unique, being the only such balances incorporating experimentally derived local deuterium values of lake evaporate. This study represents the only thermal balance, the only accurate determination of pan-lake coefficients and the first calibration of commonly used empirical evaporation equations for Swan Coastal Plain wetlands. Groundwater levels in the western suburbs of Perth have declined over 40 years and a disproportionate larger decline now seriously threatens Perry Lakes. Modelling suggests regional groundwater extraction exceeds recharge. Wetland managers can no longer maintain East Lake via local groundwater extraction. Artificial recharge using imported surface and waste water are possible future management options.

Feedbacks between climate, tectonics and erosion drive mineral dissolution in the subsurface and may provide strong controls on chemical weathering as a mechanism for modulating climate through CO2 drawdown. However, few quantitative evaluations of chemical weathering intensity or flux variations with time exist to support this hypothesized feedback. Trace element concentrations in colluvial sediment demonstrate that in unglaciated mid-latitude terrain, climate exerts a strong control on chemical weathering intensity and erosion over glacial-interglacial cycles by modulating the efficacy of abiotic and biotic processes. Weakly chemically altered sediment corresponds with high erosion rates during the Last Glacial interval (vice versa during the Holocene) such that we observe stable weathering rates despite variations in temperature and vegetation. Our results suggest that climate-weathering feedbacks in mid-latitude regions may be weaker than previously hypothesized and provide a new framework to explain stable solute fluxes over Milankovitch climate fluctuations. / 10000-01-01

Os metais duros constituem um grupo de materiais conhecidos como compósitos sinterizados que associam fases duras (carbetos), com uma fase metálica, sendo amplamente utilizados em aplicações em que se deseja elevada dureza e resistência ao desgaste, aliada à alta tenacidade. Neste trabalho apresentam-se os resultados da adição de 1% em peso dos elementos Nb, Ti, Cr e Mo na microestrutura do metal duro a partir de um compósito comercial de WC-6Co. A este compósito foi adicionado 1,5% (em peso) de estearato de zinco como lubrificante e sinterizados na temperatura de 1450 °C numa atmosfera de Argônio. Com o objetivo de analisar a eficiência do produto, realizou-se a caracterização microestrutural por meio dos ensaios de densidade à verde, da contração volumétrica, da densidade da sinterização, da microestrutura e da microdureza. / Hard metals are a group of materials known as sintered composites, that join hard phases (carbides) and a tough metallic phase, being widely used in applications where high hardness and wear resistance combined with high toughness are necessary. This work presents the results of addition of 1% (wt %) of the elements Nb, Ti, Cr and Mo on the microstructure of the WC-6Co commercial composite. 1,5% (wt %) zinc stearate was added as a lubricant and the samples were sintered at 1450 ºC under an argon atmosphere. The samples obtained were characterized using green density, shrinkage, sintered density and microhardness tests as well as microstructural analysis.

Lagoons are coastal waterbodies which are sensitive to meteorological and hydrological changes. This study focused on the spatial distribution of salinity in Gialova lagoon, Greece. The area in which the lagoon is located is under pressure from agriculture and truism in the area. Besides that, the lagoon is an important stop for migratory birds as well as the home for rare species. To investigate how salinity is distributed in the lagoon a salinity gradient was produced. Also, an attempt was made to model the salt and fresh water fluxes in the lagoon using a mass balance approach. The water fluxes are either from fresh water sources or influx of saline water from the sea. Manual electric conductivity measurements were taken during a field campaign to the lagoon. Time series data used in the model was obtained from stations in the lagoon and the surroundings. An investigation in how the lagoon measurement station differ in salinity was also performed in this study. Results from the gradient map and manual measurements show that the water in the lagoon is the freshest in the North-Eastern parts and the most saline to the South-West. The modelled water fluxes show an inverse relationship from each other. High fresh water fluxes correspond to precipitation events, lower salinity concentration. Whereas high salt water fluxes correspond to high salinity concentration and lowered precipitation. The stations concentrated to the middle lagoon show corresponding values in salinity whereas the station to the South-West differs. The canal surrounding the lagoon shows interactions since measurements show that the water is brackish. A longer time series could provide patterns in water fluxes over time. Trying to find the portions of terrestrial groundwater and surface water, and further investigation of the regional aquifer could provide new information to develop this model. The region is expected to experience water stress which makes further studies and monitoring important.

Pureza é um dos principais atributos de qualidade de matérias-primas farmacêuticas, já que a identificação e determinação quantitativa de impurezas podem ajudar a controlar/minimizar o risco de efeitos adversos de medicamentos. O papel dos métodos de doseamento, tanto específicos como não específicos, em caracterizar a qualidade de matérias-primas farmacêuticas, tem sido questionado. Por outro lado, a abordagem do balanço de massas, que quantifica cada impureza orgânica bem como substâncias voláteis e cinzas, e então subtrai a soma destas impurezas de 100%, pode oferecer uma melhor maneira de determinar com exatidão se o fármaco atende aos critérios regulatórios de aceitação e de detectar com confiança mudanças não esperadas na qualidade do fármaco. O objetivo do estudo foi comparar métodos de doseamento compendiais com essa abordagem de balanço de massas na determinação do conteúdo de substância ativa e caracterização da qualidade de matérias-primas farmacêuticas. Os fármacos empregados neste estudo foram o nifedipino, o diazepam, a glibenclamida e a estavudina. A identificação e caracterização dos fármacos foram realizadas por meio de determinação do ponto de fusão e espectroscopia no infravermelho. Para a determinação quantitativa foram empregados os métodos presentes na Farmacopéia Brasileira, United States Pharmacopeia e British Pharmacopeia. O detector de aerossol carregado (CAD) foi acoplado ao sistema de cromatografia à líquido de alta eficiência para comparação das respostas com o detector ultravioleta. Os resultados demonstraram a viabilidade do método indireto, que oferece dados mais precisos que os do método direto, além de favorecer um controle de qualidade mais focado no perfil de impurezas. / Purity is one of the main attributes of quality of bulk drug materials, since the identification and quantitative determination of impurities can help to avoid or at least control/minimize the risk of their contribution to the side effects profile of drug materials. The role of assay methods, either specific or non-specific, in characterizing the quality of bulk drug materials, has been questioned. On the other hand, the mass balance approach, which quantifies every organic impurity as well as volatile substances and ashes, and then subtracts the sum of these impurities from 100%, can provide a better way to accurately determine if the drug substance meets the regulatory acceptance criteria and to reliably detect unexpected changes in the quality of the drug substance. The objective of this study was to compare compendial assay methods with a mass balance approach in the determination of the active ingredient content and characterization of the quality of bulk drug materials. The identification and characterization of the drugs were accomplished through determination of melting point and infrared spectroscopy. The methods from the Farmacopeia Brasileira, United States Pharmacopeia and British Pharmacopoeia were used for the quantitative determination of the drugs. The drug related impurities were determined by high performance liquid chromatography (HPLC) equipped with an ultraviolet (UV) detector and charged aerossol detector (CAD) in tandem. The results demonstrated the feasibility of the indirect method, which offers more precise data than those from the direct method, besides it enables the quality control to be focused on the impurity profile.

A dissertação versa sobre a lateritização do depósito Madeira que ocorre associado à fácies albita granito do granito Madeira (tipo A, ~ 1,82 Ga). O depósito Madeira situa-se na floresta amazônica, onde intemperismo químico é intenso e lateritização é um importante processo de formação de depósitos minerais. Este depósito representa um caso particular, onde a rocha-mãe é um depósito mineral; assim, mineralização primária e mineralização laterítica ocorrem no mesmo perfil. A rocha-mãe tem uma associação mineral incomum, que inclui quartzo, albita, k-feldspato, zircão, criolita (Na3AlF6), fluorita, polilitionite, riebeckita rica em Zn, F-anita rica em Zn, torita, cassiterita, pirocloro, columbita, xenotima, gagarinita- (Y), fluocerita-(Ce) e genthelvite. Uma característica importante da rocha é a sua riqueza em flúor (2 a 6% em peso), principalmente sob a forma de criolita ou fluroita na matriz. Inicialmente foram investigadas as alterações micromorfológicas destes minerais ao longo de perfis de intemperismo. Em seguida, os realizados estudos geoquímicos em perfis selecionados. Os dados químicos foram convertidos em proporções volumétricas para quantificar as variações nos teores de elementos em amostras com diferentes graus de lateritização, e foram realizados cálculos de balanço de massa tendo o Al como elemento de referência. Desta forma, foram obtidas muitas informações sobre os processos que atuaram na formação do perfil laterítico a partir do depósito Madeira. A rocha-mãe representava claramente um sistema aluminoso com quantidades mais baixas de Fe. A perda total de álcalis e perda parcial de SiO2 originou argilas cauliníticas. A razão molar de SiO2/Al2O3~2 foi adequada para a geração de minerais de argila aluminosos com estrutura 1:1, tais como a caulinita. Com a maior perda de SiO2 na parte superior do perfil ocorreu a formação de gibsita. Hematita é principal mineral de ferro formado porque o meio foi alcalino com alta razão OH/Fe (>2). A lixiviação de elementos alcalinos conduziu ao enriquecimento relativo de alguns elementos economicamente importantes, tais como Sn, Nb e ETR. No entanto, a distribuição de alguns metais, tais como o Pb, Zn e ETR, difere do padrão normalmente esperado no intemperismo, o que pode ser explicado por algumas características especiais da paragênese e pela alta atividade de F nas soluções, que influenciou os processos intempéricos de duas maneiras diferentes: intensa corrosão até mesmo de minerais muito resistentes e formação de complexos estáveis, especialmente com cátions duros, tais como os ETR. / The paper deals on the laterization of the Madeira deposit associated with the albite-enriched granite facies of the A-type Madeira granite (~1.82 Ga). The Madeira deposit is located in the Amazon rain forest, where chemical weathering is intensive and lateritization is a major process of ore deposit formation. This deposit represents a particular case, where the parent rock is an ore deposit; thus primary mineralization and lateritic mineralization occur in the same profile. The parent rock has an unusual mineral association, which includes quartz, albite, k-feldspar, zircon, cryolite (Na3AlF6), fluorite, polylithionite, Zn-rich riebeckite, Zn-F-rich annite, thorite, cassiterite, pyrochlore, columbite, xenotime, gagarinite-(Y), fluocerite-(Ce), and genthelvite. An important feature of the rock is the F richness (2 to 6% wt) mainly in the form of cryolite or fluorspar in the matrix. We first investigated the micromorphological changes of these minerals throughout the soil profile and then focused the geochemical studies in selected profiles. The chemical data were converted into volumetric proportions to quantify the variations in element contents in samples with different degrees of lateritization, and we performed mass balance calculations with Al as the reference element. In this way, we obtain many new constraints on the processes that formed the weathering profile from the Madeira deposit. The parental rock was a clearly aluminous system with lower amounts of Fe. The total loss of alkalis and partial loss of SiO2 created kaolinitic clay minerals. The SiO2/Al2O3 molar ratio ≈2 was suitable for generating aluminous clay minerals with 1:1 structures, such as kaolinite. Greater losses of SiO2 occurred and gibbsite formed at the top of the weathering profiles. Hematite formed as the main ferric mineral because the medium was alkaline with a high OH-/Fe ratio (> 2). The leaching of alkaline elements led to relative enrichment in some economically important elements, such as Sn, Nb, and REEs, in the lateritic profiles. However, the distribution of some of the metals, such as Pb, Zn, and REEs, in the weathering profile is very unusual and may be explained by some special characteristics of the paragenesis and the high activity of F in the solutions, which greatly influenced the weathering processes in two different ways. This halogen was responsible for the intense corrosion of even very resistent minerals and formed stable complexes, especially with hard cations such as REEs.

abstract: This dissertation focused on the development and application of state-of-the-art monitoring tools and analysis methods for tracking the fate of trace level contaminants in the natural and built water environments, using fipronil as a model; fipronil and its primary degradates (known collectively as fiproles) are among a group of trace level emerging environmental contaminants that are extremely potent arthropodic neurotoxins. The work further aimed to fill in data gaps regarding the presence and fate of fipronil in engineered water systems, specifically in a wastewater treatment plant (WWTP), and in an engineered wetland. A review of manual and automated “active” water sampling technologies motivated the development of two new automated samplers capable of in situ biphasic extraction of water samples across the bulk water/sediment interface of surface water systems. Combined with an optimized method for the quantification of fiproles, the newly developed In Situ Sampler for Biphasic water monitoring (IS2B) was deployed along with conventional automated water samplers, to study the fate and occurrence of fiproles in engineered water environments; continuous sampling over two days and subsequent analysis yielded average total fiprole concentrations in wetland surface water (9.9 ± 4.6 to 18.1 ± 4.6 ng/L) and wetland sediment pore water (9.1 ± 3.0 to 12.6 ± 2.1 ng/L). A mass balance of the WWTP located immediately upstream demonstrated unattenuated breakthrough of total fiproles through the WWTP with 25 ± 3 % of fipronil conversion to degradates, and only limited removal of total fiproles in the wetland (47 ± 13%). Extrapolation of local emissions (5–7 g/d) suggests nationwide annual fiprole loadings from WWTPs to U.S. surface waters on the order of about one half to three quarters of a metric tonne. The qualitative and quantitative data collected in this work have regulatory implications, and the sampling tools and analysis strategies described in this thesis have broad applicability in the assessment of risks posed by trace level environmental contaminants. / Dissertation/Thesis / Doctoral Dissertation Civil and Environmental Engineering 2015

A dissertação versa sobre a lateritização do depósito Madeira que ocorre associado à fácies albita granito do granito Madeira (tipo A, ~ 1,82 Ga). O depósito Madeira situa-se na floresta amazônica, onde intemperismo químico é intenso e lateritização é um importante processo de formação de depósitos minerais. Este depósito representa um caso particular, onde a rocha-mãe é um depósito mineral; assim, mineralização primária e mineralização laterítica ocorrem no mesmo perfil. A rocha-mãe tem uma associação mineral incomum, que inclui quartzo, albita, k-feldspato, zircão, criolita (Na3AlF6), fluorita, polilitionite, riebeckita rica em Zn, F-anita rica em Zn, torita, cassiterita, pirocloro, columbita, xenotima, gagarinita- (Y), fluocerita-(Ce) e genthelvite. Uma característica importante da rocha é a sua riqueza em flúor (2 a 6% em peso), principalmente sob a forma de criolita ou fluroita na matriz. Inicialmente foram investigadas as alterações micromorfológicas destes minerais ao longo de perfis de intemperismo. Em seguida, os realizados estudos geoquímicos em perfis selecionados. Os dados químicos foram convertidos em proporções volumétricas para quantificar as variações nos teores de elementos em amostras com diferentes graus de lateritização, e foram realizados cálculos de balanço de massa tendo o Al como elemento de referência. Desta forma, foram obtidas muitas informações sobre os processos que atuaram na formação do perfil laterítico a partir do depósito Madeira. A rocha-mãe representava claramente um sistema aluminoso com quantidades mais baixas de Fe. A perda total de álcalis e perda parcial de SiO2 originou argilas cauliníticas. A razão molar de SiO2/Al2O3~2 foi adequada para a geração de minerais de argila aluminosos com estrutura 1:1, tais como a caulinita. Com a maior perda de SiO2 na parte superior do perfil ocorreu a formação de gibsita. Hematita é principal mineral de ferro formado porque o meio foi alcalino com alta razão OH/Fe (>2). A lixiviação de elementos alcalinos conduziu ao enriquecimento relativo de alguns elementos economicamente importantes, tais como Sn, Nb e ETR. No entanto, a distribuição de alguns metais, tais como o Pb, Zn e ETR, difere do padrão normalmente esperado no intemperismo, o que pode ser explicado por algumas características especiais da paragênese e pela alta atividade de F nas soluções, que influenciou os processos intempéricos de duas maneiras diferentes: intensa corrosão até mesmo de minerais muito resistentes e formação de complexos estáveis, especialmente com cátions duros, tais como os ETR. / The paper deals on the laterization of the Madeira deposit associated with the albite-enriched granite facies of the A-type Madeira granite (~1.82 Ga). The Madeira deposit is located in the Amazon rain forest, where chemical weathering is intensive and lateritization is a major process of ore deposit formation. This deposit represents a particular case, where the parent rock is an ore deposit; thus primary mineralization and lateritic mineralization occur in the same profile. The parent rock has an unusual mineral association, which includes quartz, albite, k-feldspar, zircon, cryolite (Na3AlF6), fluorite, polylithionite, Zn-rich riebeckite, Zn-F-rich annite, thorite, cassiterite, pyrochlore, columbite, xenotime, gagarinite-(Y), fluocerite-(Ce), and genthelvite. An important feature of the rock is the F richness (2 to 6% wt) mainly in the form of cryolite or fluorspar in the matrix. We first investigated the micromorphological changes of these minerals throughout the soil profile and then focused the geochemical studies in selected profiles. The chemical data were converted into volumetric proportions to quantify the variations in element contents in samples with different degrees of lateritization, and we performed mass balance calculations with Al as the reference element. In this way, we obtain many new constraints on the processes that formed the weathering profile from the Madeira deposit. The parental rock was a clearly aluminous system with lower amounts of Fe. The total loss of alkalis and partial loss of SiO2 created kaolinitic clay minerals. The SiO2/Al2O3 molar ratio ≈2 was suitable for generating aluminous clay minerals with 1:1 structures, such as kaolinite. Greater losses of SiO2 occurred and gibbsite formed at the top of the weathering profiles. Hematite formed as the main ferric mineral because the medium was alkaline with a high OH-/Fe ratio (> 2). The leaching of alkaline elements led to relative enrichment in some economically important elements, such as Sn, Nb, and REEs, in the lateritic profiles. However, the distribution of some of the metals, such as Pb, Zn, and REEs, in the weathering profile is very unusual and may be explained by some special characteristics of the paragenesis and the high activity of F in the solutions, which greatly influenced the weathering processes in two different ways. This halogen was responsible for the intense corrosion of even very resistent minerals and formed stable complexes, especially with hard cations such as REEs.

Pureza é um dos principais atributos de qualidade de matérias-primas farmacêuticas, já que a identificação e determinação quantitativa de impurezas podem ajudar a controlar/minimizar o risco de efeitos adversos de medicamentos. O papel dos métodos de doseamento, tanto específicos como não específicos, em caracterizar a qualidade de matérias-primas farmacêuticas, tem sido questionado. Por outro lado, a abordagem do balanço de massas, que quantifica cada impureza orgânica bem como substâncias voláteis e cinzas, e então subtrai a soma destas impurezas de 100%, pode oferecer uma melhor maneira de determinar com exatidão se o fármaco atende aos critérios regulatórios de aceitação e de detectar com confiança mudanças não esperadas na qualidade do fármaco. O objetivo do estudo foi comparar métodos de doseamento compendiais com essa abordagem de balanço de massas na determinação do conteúdo de substância ativa e caracterização da qualidade de matérias-primas farmacêuticas. Os fármacos empregados neste estudo foram o nifedipino, o diazepam, a glibenclamida e a estavudina. A identificação e caracterização dos fármacos foram realizadas por meio de determinação do ponto de fusão e espectroscopia no infravermelho. Para a determinação quantitativa foram empregados os métodos presentes na Farmacopéia Brasileira, United States Pharmacopeia e British Pharmacopeia. O detector de aerossol carregado (CAD) foi acoplado ao sistema de cromatografia à líquido de alta eficiência para comparação das respostas com o detector ultravioleta. Os resultados demonstraram a viabilidade do método indireto, que oferece dados mais precisos que os do método direto, além de favorecer um controle de qualidade mais focado no perfil de impurezas. / Purity is one of the main attributes of quality of bulk drug materials, since the identification and quantitative determination of impurities can help to avoid or at least control/minimize the risk of their contribution to the side effects profile of drug materials. The role of assay methods, either specific or non-specific, in characterizing the quality of bulk drug materials, has been questioned. On the other hand, the mass balance approach, which quantifies every organic impurity as well as volatile substances and ashes, and then subtracts the sum of these impurities from 100%, can provide a better way to accurately determine if the drug substance meets the regulatory acceptance criteria and to reliably detect unexpected changes in the quality of the drug substance. The objective of this study was to compare compendial assay methods with a mass balance approach in the determination of the active ingredient content and characterization of the quality of bulk drug materials. The identification and characterization of the drugs were accomplished through determination of melting point and infrared spectroscopy. The methods from the Farmacopeia Brasileira, United States Pharmacopeia and British Pharmacopoeia were used for the quantitative determination of the drugs. The drug related impurities were determined by high performance liquid chromatography (HPLC) equipped with an ultraviolet (UV) detector and charged aerossol detector (CAD) in tandem. The results demonstrated the feasibility of the indirect method, which offers more precise data than those from the direct method, besides it enables the quality control to be focused on the impurity profile.