Erosion, a surface process, can be quantified over long-term (assumed to be the natural erosion rate of the landscape) and contemporary (modern) timeframes. My research used the rare cosmogenic isotope 10Be in sand and cobbles collected from rivers in southeastern Brazil (Santa Catarina and Rio de Janeiro states) and southwestern China (Yunnan province) to quantify long-term, background rates of erosion and sediment supply. These measurements will also increase number of such measurements in tropical and subtropical climates. I assessed the relationship between landscape parameters (topographic and climatic) and background erosion rates in order to understand factors related to erosion. My data from so far unsampled states in Brazil shows that background erosion rates range between 13 and 90 m/Myr. I found that mean basin slope (R2=0.73) and mean annual precipitation (R2=0.57) are strongly correlated to erosion rates. Steep, escarpment-draining basins in Brazil erode faster than lower gradient basins draining the highlands. Comparing the isotopic concentration of river sand and cobbles, my data show that these grain sizes are sourced from different parts of the landscape. I compiled all published Brazilian cosmogenic 10Be data, and compared them to erosion rates from similar tectonic settings. While the erosion rates in Brazil are relatively low, they are similar to those in southeastern North America, but faster than rates measured on escarpments in southern Africa. In China, I tested the human effects on denudation by comparing long-term erosion rates derived from in-situ 10Be concentration and the modern sediment yield of 22 watersheds in Yunnan. Background erosion rates range between 17 and 386 m/Myr; long term sediment yields based on these erosion rates range from 79 to 893 tons km-2 yr-1. Modern sediment yields range from 90 to 2,879 tons km-2 yr-1 (data from Schmidt et al., 2011). In most watersheds, the modern sediment yield is 2-3X higher than long-term rates, likely the effect of a long history of land use in Yunnan. I found a statistically significant, positive relationship between erosion rates and both area (R2 = 0.60) and mean basin slope (R2 = 0.42). There is a negative but strong relationship between erosion rates and precipitation in my dataset (R2 = 0.60). I sampled some places where 10Be samples had been collected before to test the methodological assumption of time-invariant 10Be concentration. Concentrations generally agree on samples taken 6 months apart and in samples from the active channel and from floodplains, but not in samples collected a decade and centuries apart.

Programa Internacional de Becas da FundaÃÃo Ford / O processamento de materiais cerÃmicos, que envolve a queima de tijolos e demais produtos das indÃstrias cerÃmicas vermelhas, està associado à liberaÃÃo de componentes gasosos e material particulado que em fortes concentraÃÃes podem prejudicar o meio-ambiente e principalmente a saÃde humana, uma vez que os gases emitidos por estas indÃstrias, na maioria das vezes, nÃo sÃo tratados antes de serem lanÃados à atmosfera. O escopo desta pesquisa foi desenvolver um suporte cerÃmico visando, principalmente, à remoÃÃo de material particulado da indÃstria cerÃmica vermelha. Para sua obtenÃÃo foi usado resÃduo de terra diatomÃcea, ignimbrita (Sillar), e como aglomerante a bentonita, as quais possuem aproximadamente 70% a 80% de sÃlica. A sÃlica apresentando-se sob duas formas cristalinas: quartzo e cristobalita. O resÃduo, terra diatomÃcea, coletado em uma indÃstria cervejeira, foi submetido a um tratamento tÃrmico para a eliminaÃÃo da matÃria orgÃnica absorvida durante a etapa de filtraÃÃo. As matÃrias-primas foram submetidas a uma anÃlise quÃmica e mineralÃgica mediante FluorescÃncia de raios X e DifraÃÃo de raios X. Para a fabricaÃÃo do suporte cerÃmico foram preparadas espumas cerÃmicas pelo mÃtodo da replica. As espumas polimÃricas foram imersas na suspensÃo (diatomita, ignimbrita, bentonita e Ãgua), secas e tratadas termicamente. A eliminaÃÃo da espuma cerÃmica polimÃrica ocorreu a 400ÂC e, em seguida, o corpo cerÃmico foi sinterizado a 1100ÂC, em um intervalo de tempo compreendido de 45 e 60 min. Foram testadas quatro formulaÃÃes com duas variÃveis: tamanho de grÃo e composiÃÃo. A formulaÃÃo quatro (10% de diatomita e 16% de ignimbrita), foi a mais Ãtima, com uma resistÃncia mecÃnica à compresao de 0,8 MPa e uma porosidade de 81%. A reduÃÃo de material particulado, apÃs o uso do suporte cerÃmico, foi de aproximadamente 84% e de 72% de monÃxido de carbono, estando dentro dos padrÃes estabelecido pela ResoluÃÃo nÂ382/2006 do CONAMA. / The processing of ceramic materials which involves burning of the bricks and other ceramic product red ceramic industries is associated with the release of gaseous components and particulate material in high concentrations that affect the environment and human health, considering that the gases emitted by these industries are not mostly treated before being released to the atmosphere. The purpose of this research was to develop a ceramic support with the main objective of the removal of particulate matter. Was used diatomaceous earth residue, ignimbrita (Sillar) and the bentonite as a binder, which possess a high amount of silica. The silica exists in two crystalline forms: quartz, cristobalite. The residue, diatomaceous earth, collected in a beer industry, was submitted to a thermal treatment for the elimination organic matter absorbed during filtration. The raw materials were subjected to chemical and mineralogical analysis by XRF and XRD. Were processed by the replication method. The Polymeric foams were immersed in the ceramic suspension (diatomite, ignimbrita, bentonite and water), and then dried and heat-treated for consolidation. The polymer foam was burned out at 400 ÂC and sintering was carried out at 1100 ÂC for 45 - 60 min. We‟re working four formulations with two variables, grain size and composition. The four formulations (10% diatomite and 16% ignimbrita) was more excellent, mechanical strength compresao of 0,8MPa and porosity of 81%. The reduction of particulate matter after using the ceramic support was approximately 84% and carbon monoxide was 72% is within the standards established by the Resolution nÂ382/2006 do CONAMA.

Master of Science / Department of Statistics / James W. Neill / Cluster based lack of fit tests for linear regression models are generally effective in detecting model inadequacy due to between- or within-cluster lack of fit. Typically, lack of fit exists as a combination of these two pure types, and can be extremely difficult to detect depending on the nature of the mixture. Su and Yang (2006) and Miller and Neill (2007) have proposed lack of fit tests which address this problem. Based on a simulation comparison of the two testing procedures, it is concluded that the Su and Yang test can be expected to be effective when the true model is locally well approximated within each specified cluster and the lack of fit is not due to an unspecified predictor variable. The Miller and Neill test accommodates a broader alternative, which can thus result in comparatively lower but effective power. However, the latter test demonstrated the ability to detect model inadequacy when the lack of fit was a function of an unspecified predictor variable and does not require a specified clustering for implementation.

L’écologie du Desman des Pyrénées (Galemys pyrenaicus), mammifère semi-aquatique endémique de la péninsule ibérique et des Pyrénées, demeure encore très peu connue. Les objectifs de cette thèse, dans le cadre d’un Plan National d’Actions, ont été d’identifier les variables environnementales agissant sur la répartition de l’espèce à différentes échelles spatiales, en considérant sa détectabilité imparfaite (i.e. fausses absences et fausses présences). Une probabilité de détection élevée, mais spatialement hétérogène à l’échelle des Pyrénées françaises, a été mise en évidence. La distribution du Desman des Pyrénées s’est également révélée spatialement structurée et majoritairement influencée par des facteurs propres aux milieux aquatiques, mais en forte régression depuis les années 80. Ces résultats ont permis de proposer des mesures de conservation pour cette espèce menacée. / The ecology of the Pyrenean desman (Galemys pyrenaicus), a small semi-aquatic mammal endemic to the Iberian Peninsula and the Pyrenees, remains still largely unknown. The aim of this PhD thesis conducted within the framework of a National Action Plan was to identify the environmental variables influencing the Desman distribution at various spatial scales, by accounting for its imperfect detection (i.e. false absences and false presences). A high, but spatially heterogeneous at the French Pyrenees extent, probability of detection was highlighted. The distribution of the Pyrenean Desman was also emphasized to be spatially structured and mainly influenced by aquatic factors, but severely contracting for the last 25 years. These results enabled to suggest conservation measures for this endangered species.