[pt] Um modelo de descarburação e formação de escórias foi desenvolvido e aplicado ao processo de fabricação de aço em forno elétrico a arco de 120 ton de capacidade, com carga de ferro gusa e de sucata ferrosa. O carregamento de carbono foi significativamente variado para testar a consistência do modelo, considerando a cinética de oxidação do carbono, oxidação do fósforo e de redução do óxido de ferro. Gusa e coque foram empregados como fontes mais relevantes de carbono, resultando na entrada de 15 a 35 kg carbono/ton. As taxas de fusão do gusa e da sucata governam a disponibilidade dos elementos mais relevantes tais como carbono, fósforo e silício em solução, portanto, afetam as taxas de descarburação e de formação de escórias. A principal fonte de fósforo na carga ferrosa é o gusa. Desta forma, a evolução do teor de fósforo na fase metal mostrou-se importante para as estimativas das taxas de fusão do gusa, uma vez que o fósforo pode ser empregado como traçador adicional ao carbono. Modelos cinéticos envolvendo as reações do fósforo e silício operam simultaneamente com os modelos cinéticos referentes às reações do carbono e do ferro. Integrações numéricas associadas a um algoritmo de gradientes reduzidos generalizado foi empregado para o sistema não linear com restrições, de forma a determinar a maioria dos parâmetros cinéticos do modelo. A taxa de fusão global da carga de sucata foi maior do que a taxa de fusão aparente do gusa. Supõe-se que, o gusa apesar de ter relações geométricas desfavoráveis à transferência de calor em relação à sucata, poderia fundir mais rapidamente influenciado pelo seu baixo ponto de fusão. Entretanto, devido à formação de camada solidificada a partir da massa líquida na qual é imerso, é provável que mesmo fundido posteriormente, ocorra um processo de encapsulamento temporário, conferindo-lhe uma taxa aparente de fusão mais baixa. A constante cinética da reação de descarburação quando o teor de carbono é inferior ao carbono crítico de 0.19 por cento em massa e pelo menos 60 por cento da carga ferrosa estão fundidas, foi estimada em 0.74 min-1, taxas comparáveis às obtidas em aciaria a oxigênio. A principal fonte de oxigênio para oxidação do ferro é disponibilizada por lanças supersônicas. Estima-se que 20 por cento do oxigênio injetado via lanças sejam consumidos para a formação de óxido de ferro. Entretanto, cerca de 31 por cento e 26 por cento do oxigênio oriundo de injetores de póscombustão podem contribuir na formação de óxido de ferro ou são captados pelo sistema de exaustão de gases, respectivamente. Os resultados indicam que em torno de 15-30 por cento do carbono injetado podem não reagir no forno, sendo removidos com a escória. Adicionalmente ao estado de não-equilíbrio no sistema Fe-C-O observado, a dispersão nas estimativas de carbono solúvel na fase metal também pode ter sido influenciada pela intensidade de penetração da injeção de coque. O algoritmo proposto se constitui num promissor simulador de práticas que visam otimizar o rendimento metálico do ferro, a partir da dependência da cinética de redução do óxido de ferro com sua atividade química na escória. / [en] A decarburization and slag formation model was developed and applied to a steelmaking process based on scrap and pig iron mixes melted in a conventional AC electric arc furnace (EAF) with 120 ton capacity. The amount of carbon input was varied significantly in order to evaluate the model consistency regarding mainly the kinetics of carbon oxidation, phosphorus oxidation and iron oxide formation and reduction. Pig iron and coke were used as sources of carbon, resulting in variation of total carbon input in the range of 15 to 35 kg carbon/ton. The pig iron and scrap melting rates determine the availability of the most relevant elements such as carbon, phosphorus and silicon in solution in Fe-C melts, and therefore, affecting the decarburization as well the slag formation rates. The pig iron is the main source of phosphorus in the ferrous charge. Hence, the evolution of the phosphorus content in the metal phase is important to predict the pig iron melting rate, since phosphorus can be used as a tracer element in addition to carbon. Kinetic models regarding phosphorus and silicon were applied simultaneously to kinetic models of carbon and iron reactions. A numerical integration method supported a generalized reduced gradient algorithm for non-linear and constrained system (GRG) was applied to determine most of the kinetic model parameters. The scrap melting rates were found to be higher than pig iron apparent melting rates. This is expected that, even though the heat transfer issues related to significant differences in the area to volume ratio compared to scrap, pig iron may melt faster influenced by its low melting point. However, a solidified shell maybe created from the hot heel where pig iron is immersed, even when further melting occur, Fe-rich carbon melts could be encapsulated temporarily and present lower apparent melting rate. The decarburization rate parameter, when at least 60 percent of the charge is melted, was estimated as 0.74 min-1, when carbon content is lower than the critical carbon 0.19 percent wt, which is similar to the rate range observed in oxygen steelmaking facilities. Around 31 percent and 26 percent of the oxygen input through post combustion injectors were addressed to iron oxidation and to the off-gas system, respectively. The main source of oxygen taking part of iron oxidation is available from supersonic lances. Approximately 20 percent of the oxygen input through lancing are consumed to form iron oxide. The results also indicate about 15-30 percent of the injected carbon may not react and leave EAF during slagoff. In addition to the observed non-equilibrium state in Fe-C-O system, the dispersive behavior of the prediction of soluble carbon content in the metal phase could also be influenced by the intensity of penetration coke. The model framework is a promising tool to work preliminarily in what-if process scenario builder as a static model for iron yield optimization, regarding the kinetics of iron oxide reduction reaction and the proposed dependence on its chemical activity in the slag phase.

Estimating mass changes of ice sheets or of the global ocean from satellite gravimetry strongly depends on the correction for the glacial isostatic adjustment (GIA) signal. However, geophysical GIA models are different and incompatible with observations, particularly in Antarctica. Regional inversions have resolved GIA over Antarctica without ensuring global consistency, while global inversions have been mostly constrained by a priori GIA patterns. For the first time, we set up a global inversion to simultaneously estimate ice sheet mass changes and GIA, where Antarctic GIA is spatially resolved using a set of global GIA patterns. The patterns are related to deglaciation impulses localized along a grid over Antarctica. GIA associated with four regions outside Antarctica is parametrized by global GIA patterns induced by deglaciation histories. The observations we consider here are satellite gravimetry, satellite altimetry over Antarctica and Greenland, as well as modelled firn thickness changes. Firn thickness changes are also parametrized to account for systematic errors in their modelling. Results from simulation experiments using realistic signals and error covariances support the feasibility of the approach. For example, the spatial RMS error of the estimated Antarctic GIA effect, assuming a 10-year observation period, is 31% and 51%, of the RMS of two alternative global GIA models. The integrated Antarctic GIA error is 8% and 5%, respectively, of the integrated GIA signal of the two models. For these results realistic error covariances incorporated in the parameter estimation process are essential. If error correlations are neglected, the Antarctic GIA RMS error is more than twice as large.Highlights We present a globally consistent inversion approach to co-estimate glacial isostatic adjustment effects together with changes of the ice mass and firn air content in Greenland and Antarctica. The inversion method utilizes data sets from satellite gravimetry, satellite altimetry, regional climate modelling, and firn modelling together with the full error-covariance information of all input data. The simulation experiments show that the proposed GIA parametrization in Antarctica can resolve GIA effects unpredicted by geophysical modelling, despite realistic input-data limitations.

Syfte och mål - Studien syftade till att identifiera förbättringsmöjligheter och rekommendationer för effektiv masshantering. Målet var att effektivisera masshanteringen med fokus på massbalans och därmed minska både naturresurser och klimatpåverkan för transport till och från anläggningsprojekt. Metod - Studien använde sig av kvalitativa semistrukturerade intervjuer, litteraturstudie samt multikriterieanalys. Resultat - Studiens resultat visade att tidiga utredningar i projekteringsskedet, snabbare handläggningstider, och effektiv logistik och tydliga massdispositionsplaner är centrala för effektiv masshantering inom anläggningsprojekt. Resultaten gav därmed praktiska riktlinjer för att effektivisera masshanteringen inom anläggningsbranschen och därmed förbättrad hållbarhet. Analys – Litteraturstudie och intervjuer analyserades. En multikriterieanalys genomfördes för att välja det bästa sättet att hantera massor med fokus på faktorer som tid, ekonomi och miljöpåverkan. Tidiga utredningar i projekteringsstadiet rankades högst bland sju alternativa åtgärder för effektiv masshantering enligt multikriterieanalysen. Diskussion - Betydelsen av tidiga utredningar, snabbare handläggningstider och en välplanerad logistik framhölls som viktiga åtgärder för att effektivisera masshanteringen. Diskussionen betonade också behovet av kompetenta chefer och tydliga massdispositionsplaner för att främja projektens ekonomi och hållbarhet. Trots utmaningar i multikriterieanalysen visade resultaten enighet mellan tidigare forskning och intervjuer, vilket stärkte studiens reliabilitet och validitet. Studien möjliggjorde en generalisering som kan gynna flera entreprenadföretag inom anläggningsbranschen genom att dra nytta av studiens resultat. Nyckelord – Anläggningsprojekt, effektivisering, hållbarhet, massbalans, masshantering, multikriterieanalys. / Purpose and Objectives – The study aimed to identify improvement opportunities and recommendations for efficient mass management. The goal was to make mass management more efficient with a focus on mass balance, thereby reducing both natural resources usage and climate impact associated with transportation to and from construction projects. Methodology – The study used qualitative semi-structured interviews, literature review, and a multicriteria analysis. Results – The study's findings indicated that early investigations in the design phase, faster processing times, and efficient logistics and clear mass disposal plans are crucial for effective mass management within construction projects. The results provided practical guidelines for making mass management more efficient in the construction industry and thereby improving sustainability. Analysis – Literature review and interviews were analysed. A multicriteria analysis was conducted to select the best way to handle masses, focusing on factors such as time, cost, and environmental impact. Early investigations in the design stage ranked highest among seven alternative measures for efficient mass management according to the multicriteria analysis. Discussion – The importance of early investigations, faster processing times, and carefully planned logistics was emphasized as crucial steps to improve mass management. The discussion also highlighted the need for skilled managers and clear mass disposal plans to promote project economics and sustainability. Despite facing challenges in multicriteria analysis, the results showed agreement with previous research and interviews, which strengthened the study's reliability and validity. The study enabled generalization, potentially benefiting many construction companies in the industry by using its findings. Keywords – Construction projects, efficiency, mass balance, mass management, multicriteria analysis, sustainability.

Övergödning är ett utbrett miljöproblem i hav och sjöar, som yttrar sig i toxiska algblomningar och en minskad biodiversitet. Eftersom kväve är en betydande källa till övergödning, har flera avloppsreningsverk (ARV) krav på kväveavskiljning innan utsläpp i recipient. Tierp ARV omfattas [TA1] för närvarande inte av sådana utsläppskrav på kväve, men förväntas bli det i och med kommande lagstiftning. En utbyggnad av det biologiska reningssteget, som idag endast medför viss kväveavskiljning, kan därför bli nödvändigt för att åstadkomma fullständig kväverening.  Syftet med examensarbetet var att föreslå reningstekniker som kan åstadkomma tillräcklig kväveavskiljning vid Tierp ARV och bedöma vilken av dessa som är mest fördelaktig för implementering. Vidare utvärderades nuvarande reduktion av kväve och organiskt material samt rådande nitrifikation i det biologiska reningssteget. Massbalanser upprättades utifrån provtagning på dessa parametrar. Lämpliga kvävereningstekniker föreslogs med hänsyn till lokala krav och förutsättningar. Dessa tekniker jämfördes därefter i en multikriterieanalys med avseende på platsåtgång, växthusgasutsläpp, drift- och underhållskostnader, kapitalkostnader och arbetsinsats.  Massbalanserna uppvisade en reduktion på 31 % för totalkväve, 10 % för ammoniumkväve, 63 % för nitratkväve, 7 % för nitritkväve, 62 % för COD och 67 % för BOD7. Nuvarande nitrifikation bedömdes vara relativt låg, vilket troligtvis är resultatet av den låga temperaturen på avloppsvattnet, eventuell otillräcklig syretillförsel samt ogynnsamt pH. De reningstekniker som föreslås kunna minska kväveutsläppen från Tierp ARV är aktivslamprocess, membranbioreaktor (MBR) och hybridprocess med biofilmsbärare och aktivslam (IFAS). Utifrån en samlad bedömning av kriterierna i multikriterieanalysen bedömdes IFAS som mest fördelaktig för etablering och MBR som minst gynnsamt. / Eutrophication is a major environmental problem in oceans and lakes, which manifests itself intoxic algal blooms and reduced biodiversity. As nitrogen is a significant contributor toeutrophication, numerous wastewater treatment plants (WTPs) have requirements for nitrogenremoval before discharge into the recipient. Tierp WTP is not currently subject to suchregulation, but is expected to be so with forthcoming legislation. Consequently, an expansion ofthe biological treatment, which presently facilitates only partial nitrogen removal, may becomepertinent to achieve complete nitrogen removal. The objective of this thesis was to propose treatment methods capable of achieving adequatenitrogen removal at Tierp WTP and evaluate the most suitable option for implementation.Furthermore, the current nitrogen and organic material reduction, as well as present nitrificationin the biological treatment, were assessed. Mass balances were established based on sampling ofthese parameters. Suitable nitrogen purification techniques were proposed, considering localrequirements and conditions. These techniques were then compared through a multi-criteriaanalysis, taking into account space occupancy, greenhouse gas emissions, operation andmaintenance costs, capital costs and workload. The mass balances revealed reductions of 31% for total nitrogen, 10% for ammonium nitrogen,63% for nitrate nitrogen, 7% for nitrite nitrogen, 62% for COD and 67% for BOD7. The currentnitrification was assessed as relatively low, likely attributable to the low temperature of thewastewater, possibly insufficient oxygen supply and unfavourable pH. The treatment methodsproposed in the thesis to achieve sufficient nitrogen removal at Tierp WTP are the activatedsludge process, membrane bioreactor (MBR), and hybrid process with biofilm carriers andactivated sludge (IFAS). According to the multicriteria analysis, IFAS was deemed the mostadvantageous option for implementation, while MBR was evaluated as the least favourable.

Résumé : Le contexte récent d’accélération de la fonte des glaciers et calottes glaciaires (GCG) de l’archipel arctique canadien, jumelé aux difficultés de suivi des GCG de cette région, rendent essentiels le développement et l’utilisation de nouvelles approches innovatrices de suivi. Le potentiel de la stéréo radargrammétrie (SRG) RADARSAT-2 est ici caractérisé pour l’extraction d’élévations et le calcul de changements d’élévation et de bilans de masse (historiques et récents) sur les calottes glaciaires Barnes et Penny (Nunavut, Canada). Par la méthode semi-automatisée de recherche de corrélation à partir de couples stéréoscopiques RADARSAT-2 de 2013 (mode wide ultra-fin; résolution spatiale de 3 m; taille d’image de 50 km x 50 km), une précision verticale de ~7 m (LE68) est mesurée sur la terre ferme, et cette valeur de précision est possiblement légèrement supérieure sur la calotte Barnes, étant donné la variabilité de profondeur de pénétration. Par captage 3D, une précision altimétrique de ~3-4 m (LE68) est mesurée par différents photo-interprètes à partir de couples RADARSAT de 2012 en zone d’ablation de la calotte Penny. Sur la calotte Barnes, les changements d’élévation mesurés par rapport aux premiers modèles numériques de terrain disponibles permettent de mesurer un bilan de masse spécifique historique (1960-2013) de -0,49 ± 0,20 m w.e./année, pour un bilan de masse total de -2,9 Gt/année. Entre 2005 et 2013, le bilan de masse spécifique de cette calotte augmente significativement à -1,20 ± 0,86 m w.e./année, pour un bilan de masse total de -7 Gt/année. En zone d’ablation de la calotte Penny, un changement d’élévation annuel moyen de -0,59 m/année est mesuré entre 1958 et 2012. Parallèlement, plusieurs aspects méthodologiques et techniques sont discutés et analysés. Des profondeurs de pénétration nulles (bande C) sont mesurées à partir des images acquises sur la calotte Barnes à la toute fin de la saison d’ablation (fin septembre/début octobre), alors que cette profondeur augmente à ~2,5-3 m pour des images acquises à la fin octobre/début novembre (période de gel). Nos résultats suggèrent aussi que le modèle de fonction rationnelle, lorsqu’utilisé avec des images RADARSAT-2 en mode wide ultra-fin, permet d’obtenir des précisions plus constantes que le modèle hybride de Toutin. De par son indépendance des conditions météorologiques, son utilisation possible sans point de contrôle et sa simplicité de traitement, la SRG RADARSAT-2 s’avère donc être une excellente alternative aux technologies actuelles pour le suivi de GCG situés dans des régions affectées par des contraintes opérationnelles importantes. / Abstract : Given the recent melt acceleration of the Canadian arctic archipelago’s ice caps and the monitoring difficulties of this remote region, the development of new innovative monitoring tools has become essential. Here, the potential of the RADARSAT-2 stereo radargrammetry (SRG) is characterized for elevations extraction, as well as for elevation changes/mass balances calculations (historical and recent) on Barnes and Penny ice caps (Nunavut, Canada). Using the semi-automatic approach of correlation search from RADARSAT-2 stereoscopic couples of 2013 (wide ultra-fine mode; spatial resolution of 3 m; coverage of 50 km x 50 km), a vertical precision of ~7 m (LE68) is measured on ice-free terrain and this precision is possibly slighty worse on the ice cap because of the penetration depth’s variability. On the other hand, the 3D vision extraction approach reveals an altimetric precision of ~3-4 m (LE68) on the ablation area of the Penny Ice Cap. On the Barnes Ice Cap, elevation changes calculated relative to the oldest digital elevation models available allows to calculate an historical specific mass balance (1960-2013) of -0,49 ± 0,20 m w.e./year, resulting in a total annual mass balance of -2,9 Gt/year. Between 2005 and 2013, the specific mass balance of this ice cap increases to -1,20 ± 0,86 m w.e./year, which equals to a total annual mass balance f -7 Gt/year. On Penny Ice Cap’s ablation area, an average elevation change of -0,59 m/year is measured between 1958 and 2012. As also suggested in the literature, the recent melt acceleration is highly linked to warmer summer temperatures. Methodological and technical aspects are also presented and analyzed. No penetration depth (C band) is perceived on elevations derived from late ablation season images (late September/beginning of October), while a penetration of ~2,5-3 m is measured from images acquired in late October/beginning of November (freeze period). Our results also suggest the superiority and better consistency of the rational function model for geometrical correction of wide ultra-fine mode RADARSAT-2 images, compared to the hybrid Toutin’s model. Because of its all-weather functionality, its possible use without any ground control point and the simplicity and facility of its treatment, the RADARSAT-2 SRG represents a really good technology for glacier monitoring in regions affected by serious operational constraints.

<p>This report is commissioned by the Water and Sewage Agency in The City of Mariehamn, Åland. The basic aim is to investigate positive or negative effects of a relocation of the sewage pipe from a wastewater treatment plant, Lotsbroverket. The environmental licence of Lotsbroverket is to be revised and The Environmental Appeal Board at Åland’s Government and Administrative Board has made demands that several possible locations in an outer water area should be examined. The present location of the sewage pipe is in Svibyviken, which has been classified as an “inner water area”.</p><p>The objective of this work is to study to which extent the nutrient loading from Lotsbroverket influence the environmental conditions in Svibyviken, and to investigate the suitability of different locations of the wastewater pipe from Lotsbroverket.</p><p>The way a coastal area looks, i.e., its morphometry, determines to a large extent its ecological characteristics. The investigated coastal area was digitalized from a nautical chart. The software used for this was Roots 3.3 and the GIS-tool ArcGIS 8.3. The localization of the coastal boundaries for the entire coastal area and for investigated sub-areas was determined according to the topographical bottleneck method, i.e., the boundary lines were drawn where the exposure of the coast to the open sea is minimized.</p><p>A process-based dynamic mass-balance model for total phosphorous has been used in this study. Using this model, one can estimate and quantify the effects of different nutrient sources in coastal areas. All the fluxes of phosphorous to, from and within the defined areas were studied and ranked. Model simulations have shown how changes in any of the phosphorous fluxes influence the mean monthly concentrations of total phosphorous. The situation for total nitrogen was determined with a statistical/empirical regression model between phosphorous and nitrogen concentrations. To estimate the expected ecological effects from a change in the nutrient loading from Lotsbroverket, statistical/empirical correlations between modelled nutrient concentrations and ecological effect variables have been used. Standard effect variables for the study of eutrophication effects in coastal areas are, e.g., the chlorophyll concentration, Secchi depth and oxygen saturation in deep water. These variables have also been used in this study.</p><p>It has been shown that (1) the nutrient concentrations of the Baltic Sea controls the concentration of nutrients in the studied areas to a very large extent, (2) that the nutrient fluxes from Lotsbroverket are small compared to the nutrient fluxes from the Baltic Sea and hence also of minor importance for the nutrient state of the receiving water system, (3) that the influence of the nutrient emissions from Lotsbroverket are most noticeable in the present inner recipient, Svibyviken, and (4) that the impact logically decreases with distance between the location of the sewage pipe and boundary line to the open sea. The overall conclusion is that no major improvement of the conditions in Svibyviken can be expected by a reduction or a relocation of the nutrient emissions from Lotsbroverket.</p> / <p>Detta examensarbete är ett uppdrag av VA-verket vid Mariehamns stad, Åland, med syfte att utreda effekter av en eventuell flyttning av avloppsreningsverket Lotsbroverkets utloppsledning. Inför en revidering av Lotsbroverkets miljötillstånd har Miljöprövningsnämnden vid Ålands landskapsregering ställt villkor på att tillståndshavaren skall utreda möjligheter till att avleda det renade avloppsvattnet till ett yttre vattenområde. Utloppsledningen mynnar i dagsläget i Svibyviken, vilken har klassificerats som ett inre vattenområde.</p><p>Målsättningen med detta arbete är att belysa vilka ekologiska effekter näringsämnesutsläppet från Lotsbroverket har på primärrecipienten Svibyviken samt att undersöka några andra områdens lämplighet som mottagare av avloppsvattnet. Ett kustområdes utseende och form, det vill säga dess morfometri, avgör i stor utsträckning dess ekologiska förhållanden. För att få en god bild av det undersökta områdets morfometri digitaliserades området utifrån ett sjökort i digitaliseringsprogrammet Roots 3.3, varefter data bearbetades med GIS-verktyget ArcGIS 8.3. Avgränsning av kustområdet som helhet och av undersökta delområden gjordes enligt den topografiska flaskhalsmetoden, det vill säga så att kustens öppenhet mot utanförliggande hav eller vattenområde minimeras (Håkanson et al., 1984; Pilesjö et al., 1991).</p><p>För arbetet har en processbaserad, dynamisk massbalansmodell för totalfosfor använts. Modellen har tagits fram för att eutrofieringseffekter i kustområden skall kunna studeras (Håkanson & Karlsson, 2001). Vid användandet av modellen kan effekter av olika näringsämneskällor uppskattas och kvantifieras. Samtliga totalfosforflöden till, från och inom olika avgränsade områden har studerats och rangordnats. Modellsimuleringar har visat hur förändringar i något av fosfortillflödena inverkar på recipientens månadsmedelkoncentration av totalfosfor. Situationen för kväve har undersökts med hjälp av en statistisk/empirisk regressionsmodell mellan fosfor- och kvävehalt. För att belysa de ekologiska effekter som kan förväntas efter en förändring av Lotsbroverkets fosfor- och kväveutsläpp har statistiska/empiriska kopplingar gjorts mellan näringsämneskoncentrationer och ekologiska effektvariabler. Bra effektvariabler vid undersökning av eutrofieringseffekter är exempelvis klorofyllhalt, siktdjup samt syrgashalt i bottenvattnet. Dessa variabler har också använts i detta arbete.</p><p>Resultaten visar att (1) närsaltskoncentrationerna i de studerade områdena i hög grad styrs av den allmänna eutrofieringsnivån i Östersjön, (2) att utsläppet av näringsämnen från Lotsbroverket inte inverkar på recipientens näringsstatus i någon stor utsträckning, (3) att Lotsbroverkets påverkan är störst på nuvarande recipient, Svibyviken, (4) och att påverkan sedan successivt minskar ju längre ut mot öppna havet utloppsledningen lokaliseras. Slutsatsen av utredningen är att en reduktion av Lotsbroverkets utsläpp eller nylokalisering av utloppsledningen inte kan förväntas ge någon omfattande förbättring av tillståndet i Svibyviken.</p>

Reservatórios de usinas hidrelétricas instalados em regiões tropicais podem representar contribuição significativa para as emissões de gases efeito estufa (GEEs) para a atmosfera. Neste contexto, é relevante desenvolver métodos para avaliação da emissão de CH4 e CO2 causada pela instalação desses empreendimentos hidrelétricos. A UHE Belo Monte no Rio Xingu (leste da Amazônia) é a terceira maior usina hidrelétrica em potencial de geração de energia do mundo. A estimativa das emissões de GEEs associadas à UHE Belo Monte é exemplo de alta relevância que pode servir de base para futuros empreendimentos previstos para serem construídos na região amazônica. Neste estudo, foram realizados experimentos de incubação de solos e de inundação de testemunho de solos das áreas dos reservatórios da UHE Belo Monte. Estes experimentos auxiliaram na compreensão da resposta do fluxo de CH4 e CO2 tanto na resolução vertical (e.g. profundidade), quanto na resolução horizontal (e.g. contexto fisiográfico). Os resultados demonstraram alta produção de CH4 e CO2 na camada superior (10 cm), a qual apresenta conteúdo orgânico mais elevado. O solo de floresta de igapó apresentou a maior taxa potencial de produção de CH4 (15,59 nmol CH4 g-1 h-1), enquanto que o solo de pasto apresentou a maior taxa de produção de CO2 (34,96 nmol CO2 g-1 h-1). As emissões médias de CH4 e CO2 para os reservatórios da UHE Belo Monte foram, respectivamente, iguais a 54 ± 60 mmol CH4 m-2d-1 e 330 ± 149 mmol CO2 m-2 d-1. Esses resultados indicam incremento no fluxo de CH4 e CO2 em relação ao fluxo natural destes gases no Rio Xingu medido antes da instalação da UHE Belo Monte. Isto permite computar as emissões de CH4 e CO2 na energia gerada para a avaliação do custo-benefício do empreendimento hidrelétrico, em termos de emissões de CH4 e CO2 para a atmosfera. Além disso, foram realizadas projeções de emissões de carbono ao longo de 100 anos de operação da UHE Belo Monte e a elaboração de modelo do balanço de massa de carbono (\"C budget\") para os reservatórios da UHE Belo Monte. Estimou-se que o impacto em emissões líquidas do empreendimento ocasionaria emissões entre 2,3 e 15,1 Tg C para o período de 100 anos. Dessa forma, espera-se que este estudo sirva de base para avaliar casos análogos, já que o plano de expansão da matriz energética brasileira considera a instalação de outras usinas hidrelétricas em rios do leste amazônico / Hydroelectric reservoirs installed in tropical regions can represent a significant contribution to greenhouse gas emissions (GHGs) to the atmosphere. In this context, it is relevant to develop methods to evaluate CH4 and CO2 emissions caused by the installation of hydroelectric reservoirs. The Belo Monte hydroelectric plant in Xingu River (eastern Amazon) is the third largest hydroelectric plant in the world in terms of installed capacity and is an example of high relevance that can serve as a study case to evaluate future hydroelectric projects planned to be built in the Amazon region. In this study, soil incubation and soil flooding experiments using samples from the Belo Monte reservoir areas were performed to understand the response of the CH4 and CO2 fluxes under impounding of the Xingu River, considering both vertical (e.g. depth) and horizontal resolution (e.g. physiographic context). The results showed a high production of CH4 and CO2 in the top layer (10 cm) of soils, due to higher organic content. The igapó forest soil presented the highest potential production rate of CH4 (15.59 nmol CH4 g -1 h -1), while pasture soil presented the highest CO2 production rate (34.96 nmol CO2 g -1 h-1). The mean fluxes of CH4 and CO2 from Belo Monte reservoirs were respectively 54.05 ± 60.73 mmol CH4 m-2 d-1 and 330.76 ± 149.83 mmol CO2 m-2 d-1. These results indicate significant increase in the CH4 and CO2 fluxes compared to the natural fluxes of CH4 and CO2 from the Xingu River before damming for construction of the Belo Monte reservoirs. This allows to calculate GHGs emissions associated with the energy generated by the Belo Monte hydroelectric plant in the first years of operation and its cost-benefit evaluation in terms of carbon emissions. In addition, carbon emission projections for the next 100 years were carried out and a model for carbon mass balance (CH4 and CO2 budget) was elaborated for the Belo Monte reservoirs. It was estimated that the net emissions of the Belo Monte reservoirs would vary from 2.3 to 15.1 Tg C for a period of 100 years. Thus, this study is expected to serve as a basis to evaluate similar cases, as the plan of expansion of Brazilian energy plans matrix considers the installation of other hydroelectric plants in rivers of eastern Amazon.

Representing more than 50% of a worldwide pharmaceutical market of US$ 400 billions, oral drug delivery systems become naturally the focus of many studies. For almost half a century scientists have attempted to develop a theoretical model capable of predicting oral drug absorption in humans. From steady state or quasi-equilibrium models to complex and computationally intractable dynamic modeling approaches, numerous research efforts tried to address the problem of interest. Surprisingly though, no simple insightful first-principle-based dynamic modeling approaches have been reported in the literature. It is the purpose of the present work to provide a simple dynamic distributed-parameter modeling approach for performance monitoring of oral drug delivery systems. As a consequence of the complexity of the gastrointestinal tract, drug oral bioavailability is influenced by many different parameters. These parameters range from the compound's physicochemical properties, the physiological factors of the environment to other factors inherent in the drug form itself known as encapsulation factors. Physicochemical properties account for parameters such as drug stability, solubility or diffusivity. Furthermore, the environment, namely the gastrointestinal tract, influences the drug delivery process to the body with its pH, intestinal transit time and the different transport mechanisms that take place. From a chemical engineering point of view, the human body's anatomy can be analyzed and conceptually realized as a transport-reaction chemical system. Within the proposed modeling framework, the stomach is modeled as a non-ideal continuous-stirred tank reactor (CSTR) and the small intestine is the place where convection-diffusion occurs. The governing transport equations have been solved at steady state conditions in a small intestine represented by the lumen surrounded by its wall. The present work however develops a systematic dynamic first-principle-based distributed-parameter modeling framework where the time-dependent convection-diffusion-reaction model equations are analytically solved, offering the concentration profile in the small intestine lumen and in the wall from the moment the drug is administered until the complete absorption or disintegration of the drug particles. Once the modeling work is performed, a thorough and insightful sensitivity analysis can be conducted in order to assess the impact of the different process parameters on drug bioavailability.

Submitted by Biblioteca de Pós-Graduação em Geoquímica BGQ (bgq@ndc.uff.br) on 2017-09-20T16:23:02Z No. of bitstreams: 1 Dissertacao_AmandaCristineSantosdaCosta (1).pdf: 3976192 bytes, checksum: 2af7ce18076b8c783880d3ac0c5acba5 (MD5) / Made available in DSpace on 2017-09-20T16:23:02Z (GMT). No. of bitstreams: 1 Dissertacao_AmandaCristineSantosdaCosta (1).pdf: 3976192 bytes, checksum: 2af7ce18076b8c783880d3ac0c5acba5 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geoquímica, Niterói, RJ / importante sistema de drenagem da Região Serrana do estado do Rio de Janeiro. É caracterizada por clima tropical de altitude úmido com pluviosidade média anual de 2300 mm e temperatura média anual de 19ºC. A geologia local é definida por granitos e gnaisses representativos da região sudeste brasileiro com domínio de quatro principais unidades litoestratigráficas: suíte Serra dos Órgãos (53%), complexo Rio Negro (14%), suíte Cordeiro (13%) e suíte Nova Friburgo (7%). A área é predominantemente florestada, porém há interferência antropogênica como atividades de agricultura, pastagem e ocupação urbana. Amostras de água foram coletadas em Fevereiro e Agosto de 2013 em 21 pontos selecionados de forma a contemplar as variações litológicas e de formas de uso do solo. Uma alíquota foi filtrada e acidificada para posterior análise de cátions e para a análise de ânions as amostras foram filtradas e congeladas. Os elementos Na+, Mg2+, Ca2+, K+, SiO2 foram analisados por ICP-OES, o elemento Al3+ por ICP-MS e PO4 3-, Cl- e SO4 2- por cromatografia iônica. Dados secundários foram levantados complementando as análises realizadas (litogeoquímica, concentração de compostos fosfatados e nitrogenados, parâmetros físico-químicos e composição da chuva). Uma análise estatística de agrupamentos separou as sub-bacias de acordo com as formas de uso do solo, mostrando forte influência sobre a qualidade das águas. Para a análise dos processos intempéricos foi selecionada uma sub-bacia de cabeceira situada em uma unidade de conservação cuja floresta encontra-se em seu clímax de maturidade, livre de influência antrópica direta. Foram reunidas informações de mineralogia essencial da subbacia, índices de saturação (PHREEQC), composição química da chuva e fluxo de elementos maiores para definir as principais reações de intemperismo atuantes e quantificar o processo de intemperismo. O plagioclásio foi identificado como principal mineral intemperizado, sendo consumido em uma taxa de 649 mol ha-1 ano-1 formando os minerais caulinita e gibbsita, e contribuindo com a liberação de no mínimo 818 e no máximo 1491 mol ha-1 ano-1 de silício no rio (valor medido). Para explicar todo este fluxo de silício medido, o solo deveria ser composto por 14% de caulinita e 86% de gibbsita em percentual relativo às duas fases minerais. Com relação à qualidade das águas superficiais foi proposta a razão Na:Si como uma alternativa simples e eficiente de avaliação da influência antrópica sob as condições de toda a bacia. Razões acima de 0,6 indicariam um ambiente afetado por atividade antrópica. Verificou-se uma boa correlação do proxy sugerido com outros compostos indicadores de poluição, com razão Na:Si mínima de 0,4 e máxima de 0,6 para pontos de cabeceira. Baixas razões de Na:Si, porém com concentrações mais elevadas de compostos nitrogenados e fosfatados foram associadas a áreas agrícolas. Para áreas onde é observada a influência de atividade antrópica urbana (esgotos domésticos), a razão apresentou valores elevados com máximo de 5,1. / The Piabanha basin is part of the Paraíba do Sul River system. It is an important drainage in the Rio de Janeiro mountainous region. It is characterized by humid altitude tropical climate with 2300mm of annual rainfall and 19ºC of average annual temperature. The local geology is defined by granites and gneisses representative of the Brazilian southeast region with the dominance of four main lithostratigraphic units: Serra dos Órgão suite (53%), Rio Negro complex (14%), Cordeiro suite (13%) and Nova Friburgo suite (7%). The area is mainly forested, however there are anthropogenic interference such as agricultural activities, pasture and urban area. Water samples were collected in February and August 2013 at 21 selected points. They were chosen to cover lithological variations and land use patterns. One aliquot was filtered and acidified for further cation analysis. Another sample aliquot was filtered and frozen to anion analysis. The elements Na+, Mg2+, Ca2+, K+, SiO2 . were analyzed by ICPOES the element Al3+ by ICP-MS and PO4 3-, Cl- and SO4 2- by ionic chromatography. Data from literature were collected (litogeochemistry, phosphate and nitrogen compounds concentration, physico-chemical parameters and rain composition). The statistical cluster analysis classified the sub-basins according to land use patterns, due to the strong influence on water quality. To the weathering processes analysis, a headwater sub-basin was selected. It is located in a conservation unit with a climax forest, free of direct anthropogenic influence. Information on this sub-basin’s essential mineralogy, saturation indexes, rain chemical composing and major elements flow were gathered so the main weathering reactions were defined in order to quantify the weathering process. The plagioclase was identified as the main weathered mineral, being consumed at a rate of 649 mol ha-1 year-1 forming the minerals kaolinite and gibbsite and contributing to the liberation of 818 at least and 1491 mols maximum ha-1 year-1 of silicon on the river (measured value). In order to explain all this measured silicon flow, the soil should be composed by 14% of kaolinite and 86% of gibbsite in percentage relative of the two mineral phases. Regarding the water quality, the Na:Si ratio was proposed as a simple and efficient way to evaluate the anthropogenic influence. Ratios above 0,6 would indicate an environment affected by anthropogenic influence. There was a good correlation of the suggested proxy with other pollutants indicator compounds, with a ratio of Na: Si minimum of 0,4 and maximum of 0,6 for headwater points. Low ratio values of Na:Si related with high concentration of N and P compounds are associated with agricultural areas because of the use of fertilizers. Areas with high urban anthropic activity showed the highest ratio values with a maximum value of 5,1.

Made available in DSpace on 2016-12-23T14:04:31Z (GMT). No. of bitstreams: 1 dissertacao Trindade.pdf: 2131237 bytes, checksum: 514907f9bd367cc5bd486dcd27fa2d9d (MD5) Previous issue date: 2009-03-13 / A identificação de fontes para material particulado tem sido um tema de crescente interesse em todo o mundo para auxiliar a gestão da qualidade do ar. Esta classe de estudos é convencionalmente baseada no uso de modelos receptores, que identificam e quantificam as fontes responsáveis a partir da concentração do contaminante no receptor. Existe uma variedade de modelos receptores disponíveis na literatura, este trabalho compara os resultados dos modelos receptores balanço químico de massa (BQM) e fatoração de matriz positiva (FMP) para o banco de dados de PM2,5, da região de Brighton, Colorado, com o intuito de investigar as dificuldades na utilização de cada modelo, bem como suas vantagens e desvantagens. Inicialmente, já é conhecido que o modelo BQM tem a desvantagem de necessitar dos perfis das fontes, determinados experimentalmente, para ser aplicado e também tem limitações quando as fontes envolvidas são similares. Já o modelo FMP não requer os perfis de fontes, mas tem a desvantagem de precisar de elevada quantidade amostral da concentração do contaminante no receptor. Os resultados mostraram, baseados nas medidas de performance que os dois modelos foram aptos para reproduzir os dados do receptor com ajustes aceitáveis. Todavia, resultados diferentes se ajustaram a medidas de performance. O modelo BQM, utilizou 9 tipos de fontes e o modelo FMP encontrou apenas 6 tipos de fontes. Constatou-se com isso que o modelo FMP tem dificuldades em modelar fontes que aparecem ocasionalmente. As fontes sulfato de amônio, solos, veículos a diesel e nitrato de amônio tiverem boas correlações nos resultados dos dois modelos de contribuições de fontes. Os perfis de fontes utilizados no modelo BQM e resultados do modelo FMP que mais se assimilaram foram das fontes nitrato de amônio, solos, sulfato de amônio e combustão de madeira e ou/ veículos desregulados. Verificou-se no modelo FMP que as espécies não características de determinadas fontes aparecem nos resultados dos perfis das fontes, o que torna-se ainda mais complexo a identificação das fontes, requerendo elevado conhecimento sobre a composição de inúmeras fontes. / The identification of sources of particulate matter has been a topic of growing interest throughout the world to assist the air quality management. This class of studies is conventionally based on the use of receptor models, which identify and quantify the sources responsible from the concentration of the contaminant in the receptor. There are a variety of receptor models, this study compares the results of chemical mass balance (CMB) and positive matrix factorization (PMF) models for a database of PM2.5, for the region of Brighton, Colorado, with a view to investigate the difficulties in the use of each model, as well as its advantages and disadvantages. It is known that the CMB model has the disadvantage of requiring source profiles, determined experimentally, to be applied and also has limitations when the sources involved are similar. On the other hand, the PMF model does not require source profiles, it has the disadvantage to require a large amount sample, in receptor. The results showed, based on performance measures that both models were able to reproduce the data of the receptor with reasonable fit. However, different results were adjusted for performance measurements. The CMB model, used 9 types of sources and PMF model found only 6 types of sources, it was noted by that what the PMF model has difficulty in modeling sources that appear occasionally. The sources ammonium sulfate, soil, diesel vehicles and ammonium nitrate have good correlation in the results of the two model of sources apportionment. The source profiles used in the CMB model and results of the PMF model that present more similarities were of the sources ammonium nitrate, soil, ammonium sulfate and combustion of wood and/or smoker vehicles. It was verified what the PMF model does not separate well species in the source profiles, therefore becomes even more complex to identify the sources in the FMP model, requiring considerable knowledge about the composition of many sources. For the database used with similar sources, the lack of confidence in the results based only on receptors models for a final decision on the source apportionment.