Western boreal peatlands have diverse ground covers of Sphagnum and brown mosses that have important hydrological controls on peatland-atmosphere interactions. Since peatland mosses are non-vascular, their shoot structural morphologies and community growth forms affect the storage and fluxes of water that are critical for maintaining productivity and evaporative functions. While many of the mechanisms of capillary rise are fairly well understood for Sphagnum mosses, there is less information on the water dynamics in communities of Tomenthypnum nitens, a dominant brown moss species in northern rich fens. This study investigated how the different hydrophysical characteristics of moss and peat profiles of T. nitens from a rich fen and intermixed Sphagnum angustifolium and Sphagnum magellanicum, from a poor fen affect capillary flow and water retention to support evaporation and productivity; and how different groundwater and atmospheric sources of water affected these processes. Laboratory investigations indicated volumetric water content and gross ecosystem productivity decrease with water table depth for both mosses without the advent of precipitation, with Sphagnum capitula retaining 10-20% more water than T. nitens due to its moss structure and pore connectivity with the water table. Consequently, Sphagnum capillary rise was sufficient to sustain both high pore-water pressures for evaporation and high water content for productivity at all water table depths due to a gradual shift in average water-retaining pore sizes with depth. The structure of T. nitens moss turfs, consisting of live shoots and a basal layer of old, partially decomposed shoots sometimes overlying well-decomposed peat makes capillary rise more difficult, requiring extremely low matric pressures at the surface, sometimes causing desiccation of the uppermost portions of moss shoots, and hence reduced productivity. Additional nocturnal sources of atmospheric water from dew, distillation, and vapour fluxes provide small, but potentially critical sources of water to rewet desiccated moss shoots for early morning productivity for both T. nitens and Sphagnum mosses. Investigations in the field, however, indicated that with frequent precipitation to rewet the moss and the turf base to refill large pores, evaporative demands at the T. nitens moss canopy could drive capillary flow from the water table to maintain adequate θ for productivity. T. nitens mosses also can grow in turfs disconnected from the underlying iii peat, so that the basal layer temporarily retains water from precipitation for capillary rise. Thus, while capillary connection of the T. nitens moss turf with the underlying peat and water table is not critical to maintain productivity, it grows in a relatively large range of elevations from the water table, compared to Sphagnum and feather mosses. Rewetting of the capitula and the raising of the water table by precipitation provided higher water matric pressures within the moss matrix, and along with high evaporative demands, provided the mechanisms for sufficient capillary flow for productivity. Thus, Sphagnum could grow in habitats far from the water table like feather mosses, although the latter did not require capillary rise for productivity. Furthermore, disequilibrium between water vapour and liquid in the pores of T. nitens in the near-surface suggested pressures calculated with the Kelvin equation may not provide an accurate characterization of actual matric pressures in the moss. However, as the disequilibrium is caused by vapour pressure gradients between the moss and the atmosphere, it is likely a driving factor that helps maintain vapour and capillary water fluxes to provide moisture for T. nitens and other mosses. These results illustrate hydrological mechanisms that explain how moss growth form and habitat are linked. As such, the Sphagnum and T. nitens mosses are well adapted to maintain capillary in their poorly drained habitats in western boreal peatlands.

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The main goal of this thesis was to find and compare salt-forming ions from samples of a subsurface zone of sandstone and other porous rocks. The surveyed samples came from different environments (humid and arid climate) from different locations in the Czech Republic, Jordan and the United States of America. Identification of various types of salt was based on evaluation of chemical analyzes of leached samples. Furthermore a laboratory experiment in which I used a fluorescein dye to observe the capillary rise and evaporation in unsaturated samples of sandstone was carried out. The salt content in the Czech Republic humid environment locations is generally lower than the one in foreign arid climate locations. Halit dominates in the locations Petra and Crystal Peak. In the other locations sulphate minerals dominate. The salts containing aluminum - alums were determined in the Czech Republic in the area of Czech Paradise and the surrounding. Relatively high concentrations of nitrate mineral nitratine were identified in the Devil's Pulpit location in Pilsen, the Czech Republic. From the observation of capillary rising experiments performed with artificially created honeycombs, I conclude that the height of the capillary rise is crucial for the transport of solution, and at a certain capillary height,...

O presente trabalho teve por objetivo avaliar o potencial do ensaio de ascensão capilar e de uma técnica de otimização de parâmetros para estimar os parâmetros hidráulicos dos solos. O ensaio de ascensão capilar é de execução simples e rápida e reflete um fenômeno condicionado pelas propriedades hidráulicas do solo. Na representação matemática da ascensão capilar, utilizou-se o modelo de Terzaghi (1943) que considerou tratar-se de uma condição de fluxo governada pela condutividade hidráulica saturada (ks), e o modelo de Lu & Likos (2004b), que utilizaram a equação de Gardner (1958) para representar a função condutividade hidráulica, considerando que o fluxo se dá em meio não saturado. O processo de otimização utilizou a rotina SOLVER componente do programa EXCEL, e foi testado utilizando-se os dados experimentais de Lane & Washburn (1946) e de Zhang & Fredlund (2009). Em seguida, resultados de ascensão capilar de oito amostras de solos típicos do Estado do São Paulo, Brasil, foram modelados com os parâmetros derivados da técnica. Observou-se que tanto o modelo de Terzaghi (1943) quanto o de Lu & Likos (2004b) conseguiram reproduzir os resultados experimentais de ascensão capilar, com melhores resultados associados ao modelo de Lu & Likos (2004b) para a maior parte dos solos analisados. A previsão da condutividade hidráulica saturada, de forma geral, diferiu menos de uma ordem de grandeza dos valores medidos experimentalmente, embora maiores discrepâncias tenham sido notadas para determinados tipos de solos. O parâmetro de Gardner da função condutividade hidráulica resultou em valores da mesma ordem de grandeza dos valores reportados na literatura para solos similares. Os resultados sobre a aplicação do ensaio de ascensão capilar e da técnica de otimização mostraram-se promissores para a determinação de parâmetros hidráulicos dos solos analisados, com a vantagem de ter-se um procedimento simples e rápido para a finalidade descrita. / This study evaluates the potential of capillary rise test and a parameter optimization technique to estimate soil hydraulic parameters. The capillary rise is a simple and expedite test that is conditioned by soil hydraulic properties. In the mathematical representation of the capillary rise we used the model of Terzaghi (1943), who considered that saturated hydraulic conductivity commands the phenomeno and the model of Lu & Likos (2004b) who used the Gardner equation (1958) to represent the hydraulic conductivity function, considering that the flow takes place in a non-saturated condition. The optimization process used the SOLVER routine, component of the EXCEL program, that was firstly tested using experimental data of Lane & Washburn (1946) and Zhang & Fredlund (2009). Then, results of capillary rise of eight samples of typical soils of the State of São Paulo, Brazil, were modeled with the parameters derived from the technique. It was observed that both the Terzaghi (1943) and Lu & Likos (2004b) models were able to reproduce the experimental results of capillarity, although the best results were yielded by the model Lu & Likos (2004b) for most soils. The prediction of saturated hydraulic conductivity, in general, differed less than one order of magnitude of experimentally measured values, although larger discrepancies have been noted for certain types of soils. The resulting Gardner parameter of the hydraulic conductivity function were of the same order of magnitude of the values reported in the literature for similar soils. The results on the application of capillary rise test and optimization technique proved promising for the determination of soil hydraulic parameters analyzed, with the advantage of having a simple and rapid procedure for the purpose described.

O presente trabalho teve por objetivo avaliar o potencial do ensaio de ascensão capilar e de uma técnica de otimização de parâmetros para estimar os parâmetros hidráulicos dos solos. O ensaio de ascensão capilar é de execução simples e rápida e reflete um fenômeno condicionado pelas propriedades hidráulicas do solo. Na representação matemática da ascensão capilar, utilizou-se o modelo de Terzaghi (1943) que considerou tratar-se de uma condição de fluxo governada pela condutividade hidráulica saturada (ks), e o modelo de Lu & Likos (2004b), que utilizaram a equação de Gardner (1958) para representar a função condutividade hidráulica, considerando que o fluxo se dá em meio não saturado. O processo de otimização utilizou a rotina SOLVER componente do programa EXCEL, e foi testado utilizando-se os dados experimentais de Lane & Washburn (1946) e de Zhang & Fredlund (2009). Em seguida, resultados de ascensão capilar de oito amostras de solos típicos do Estado do São Paulo, Brasil, foram modelados com os parâmetros derivados da técnica. Observou-se que tanto o modelo de Terzaghi (1943) quanto o de Lu & Likos (2004b) conseguiram reproduzir os resultados experimentais de ascensão capilar, com melhores resultados associados ao modelo de Lu & Likos (2004b) para a maior parte dos solos analisados. A previsão da condutividade hidráulica saturada, de forma geral, diferiu menos de uma ordem de grandeza dos valores medidos experimentalmente, embora maiores discrepâncias tenham sido notadas para determinados tipos de solos. O parâmetro de Gardner da função condutividade hidráulica resultou em valores da mesma ordem de grandeza dos valores reportados na literatura para solos similares. Os resultados sobre a aplicação do ensaio de ascensão capilar e da técnica de otimização mostraram-se promissores para a determinação de parâmetros hidráulicos dos solos analisados, com a vantagem de ter-se um procedimento simples e rápido para a finalidade descrita. / This study evaluates the potential of capillary rise test and a parameter optimization technique to estimate soil hydraulic parameters. The capillary rise is a simple and expedite test that is conditioned by soil hydraulic properties. In the mathematical representation of the capillary rise we used the model of Terzaghi (1943), who considered that saturated hydraulic conductivity commands the phenomeno and the model of Lu & Likos (2004b) who used the Gardner equation (1958) to represent the hydraulic conductivity function, considering that the flow takes place in a non-saturated condition. The optimization process used the SOLVER routine, component of the EXCEL program, that was firstly tested using experimental data of Lane & Washburn (1946) and Zhang & Fredlund (2009). Then, results of capillary rise of eight samples of typical soils of the State of São Paulo, Brazil, were modeled with the parameters derived from the technique. It was observed that both the Terzaghi (1943) and Lu & Likos (2004b) models were able to reproduce the experimental results of capillarity, although the best results were yielded by the model Lu & Likos (2004b) for most soils. The prediction of saturated hydraulic conductivity, in general, differed less than one order of magnitude of experimentally measured values, although larger discrepancies have been noted for certain types of soils. The resulting Gardner parameter of the hydraulic conductivity function were of the same order of magnitude of the values reported in the literature for similar soils. The results on the application of capillary rise test and optimization technique proved promising for the determination of soil hydraulic parameters analyzed, with the advantage of having a simple and rapid procedure for the purpose described.

Moisture damage in asphalt mixes refers to the loss of serviceability due to the presence of moisture. The extent of moisture damage, also called moisture susceptibility, depends on internal and external factors. The internal factors relate to the properties of the materials and the microstructure distribution, while the external factors include the environmental conditions, production and construction practices, pavement design, and traffic level. The majority of the research on moisture damage is based on the hypothesis that infiltration of surface water is the main source of moisture. Of the two other principal mechanisms of water transport, permeation of water vapor and capillary rise of subsurface water, the latter has been least explored. A laboratory test and analysis methods based on X-ray computed tomography (CT) were established to assess the capillary rise of water. The amount and size of air voids filled with water were used in the capillary rise equation to estimate the distribution of the contact angles between the water and the mastic. The results were able to show the influence of air void size on capillary rise and contact angles. The relationship between air void structure and moisture susceptibility was evaluated using a fundamental fracture model based on dissipated energy of viscoelastic materials. Detailed description is provided in this dissertation on the deduction of the model equation, the selection of the model parameters, and the required testing protocols. The model parameters were obtained using mechanical tests and surface energy measurements. The microstructure of asphalt mixes prepared in the laboratory having different air void structures was captured using X-ray CT, and image analysis techniques were used to quantify the air void structure and air void connectivity. The air void structure was found to influence the mix resistance to moisture damage. To validate the fracture model, asphalt mixes with known field performance were tested. The results demonstrated that the fracture model is an effective tool to characterize moisture susceptibility. In addition, the model showed good correlation with the reported field performance of the asphalt mixes. The findings of this study will be useful to highway engineers to evaluate asphalt mixes with alternative mix designs and internal air void structures and to estimate the rate of moisture infiltration in order to maximize the resistance of asphalt mixes to moisture damage.

The heterogeneous structure of fractured media can lead to complex spatiotemporal fluid invasion dynamics. It thus brings forward challenging fundamental questions in the context of out-of-equilibrium dynamical systems, but also relevant to many processes of interest. The goal of the Thesis is to study the spatio-temporal dynamics of the oil-air interface between displaced air and invading oil, in imbibition through a model open fracture. The research combines exhaustive experimental work with accurate data analysis based on methods of nonlinear statistical physics. The mean postion of the interface h(t) is studied in capillary rise experiments, giving rise to a new analytical solution for h(t). The fluctuations of the interface in forced-flow experiments are analysed in the context of kinetic roughening, characterizing a super-rough scaling scenario. Finally, the burst-like dynamics is studied by analysing the local and global velocities of the front, which are widely distributed and display complex spatio-temporal correlations. We define local and global avalanches whose sizes and durations are also widely distributed, with cutoffs that diverge with the capillary number. Intermittentcy of the global signal is quantified. The ensemble of results presented in this Thesis supports a very general picture of the nonequilibrium dynamics of slowly-driven fronts in open fractures: the lateral propagation of interfacial fluctuations is controlled by local mass conservation, through the lateral correlation length; and the advancement of the interface in the direction of propagation is controlled by the characteristic extent of the disorder d and by the mean front velocity.

Ce travail propose une étude expérimentale visant à caractériser les processus dynamiques se produisant au sein de matériaux vitreux mous. La première partie présente des mesures de diffusion de traceurs nanométriques dans la Laponite (une suspension colloïdale) obtenues par une méthode de recouvrement de fluorescence (FRAP). Cette étude montre que la diffusion varie avec la concentration de Laponite et la taille du traceur. Un modèle hydrodynamique de diffusion confinée permet de décrire quantitativement les données expérimentales. Une deuxième partie concerne l’étude expérimentale du vieillissement de matériaux vitreux. Nous testons en pratique le concept théorique de température effective. Celle-ci est obtenue grâce à la technique de FRAP par la mesure simultanée de la diffusion et la convection de sondes fluorescentes dans la Laponite en cours de prise. Contrairement à certaines mesures de la littérature, le système est bien gouverné par la température ambiante. Nous présentons ensuite une étude visant à caractériser le comportement de la Laponite cisaillée. Nous avons pour cela mis au point un dispositif permettant d’appliquer un champ électrique au système, et ainsi créer des déformations locales. L’effet obtenu s’est révélé trop faible, avec d’assez grandes incertitudes (probablement liées à la complexité du système), pour être considéré comme significatif. Enfin, nous avons étudié les propriétés du Carbopol, un fluide à seuil, en mesurant sa dynamique d’ascension par capillarité. La rugosité de surface des capillaires influe énormément sur la montée du fluide. Nous montrons aussi que l’ascension est pilotée par la rhéologie du système, notamment par le seuil d’écoulement. / This work is based on an experimental analysis of the dynamical processes which occur within soft glassy materials. The first part provides measurement results of nanotracers diffusion in Laponite (a colloidal suspension) obtained by a method of fluorescence recovery (FRAP). This study shows that the diffusion is affected by the concentration of Laponite as well as the size of the tracer. A hydrodynamic model with confined diffusion allows a quantitative description of the experimental data. In a second part, an experimental study is carried out, dealing with the aging processes of glassy materials. The theoretical concept of effective temperature is probed experimentally. The effective temperature is determined using the technique of FRAP, by simultaneously measuring diffusion and convection of fluorescent probes within the aging Laponite. Contrary to some measurements found in literature, results show that the system is controlled by the bath temperature. The following study then aims at characterizing the behavior of the sheared Laponite : an experimental device is developed in this perspective, by applying an electric field to the system and thus creating local deformations. However, the observed effect appears to be too low, with relatively large uncertainties (probably linked to the complexity of the system), which impede on the significance of our results. Finally, the properties of Carbopol, a yield stress fluid, are analyzed by measuring the dynamics of capillary rise. It is shown that the surface roughness of capillary strongly affects the rise of the fluid and that the latter is controlled by the rheology of the system, and more specifically by the yield stress value.

Quand un fluide mouillant visqueux (comme une huile) pénètre un milieu hétérogène tel qu’une fracture, l’interface (entre l’air déplacé et l’huile) développe des corrélations à longue portée menant à une dynamique spatio-temporelle complexe. Dans cette Thèse, nous avons étudié expérimentalement et théoriquement ce processus de transport d’un fluide, appelé imbibition, dans un modèle de fracture ouverte, pertinent dans diverses situations. Notre travail a combiné une étude expérimentale détaillée, avec une analyse précise des données, basées sur des méthodes de physique statistique et non-linéaire. D’abord, la position moyenne de l'interface h(t) est étudiée lors d’expériences de montée capillaire donnant lieu à une nouvelle solution analytique pour h(t). Nous avons ensuite étudié les propriétés d’invariance d’échelle de l’interface et en particulier leur évolution pour des processus d’imbibition forcées, caractérisée par un scénario dit «super-rugueux». Enfin, nous avons étudié et quantifié la dynamique intermittente par avalanches des fronts d’imbibition à partir de l’analyse multi-échelle (spatiales et temporelles) de leurs vitesses. L'ensemble des résultats présentés dans cette Thèse propose une image très générale de la dynamique hors équilibre des fronts d’imbibition se propageant lentement dans des fractures ouvertes. La propagation latérale des fluctuations interfaciales est contrôlée par conservation de la masse locale. L'avancement de l'interface dans la direction de propagation est contrôlé par l’échelle caractéristique du désordre et la vitesse moyenne du front. / The heterogeneous structure of fractured media can lead to complex spatiotemporal fluid invasion dynamics. It thus brings forward challenging fundamental questions in the context of out-of-equilibrium dynamical systems, but also relevant to many processes of interest. The goal of the Thesis is to study the spatio-temporal dynamics of the oil-air interface between displaced air and invading oil, in imbibition through a model open fracture. The research combines exhaustive experimental work with accurate data analysis based on methods of nonlinear statistical physics. The mean postion of the interface h(t) is studied in capillary rise experiments, giving rise to a new analytical solution for h(t). The fluctuations of the interface in forced-flow experiments are analysed in the context of kinetic roughening, characterizing a super-rough scaling scenario. Finally, the burst-like dynamics is studied by analysing the local and global velocities of the front, which are widely distributed and display complex spatio-temporal correlations. We define local and global avalanches whose sizes and durations are also widely distributed, with cutoffs that diverge with the capillary number. Intermittentcy of the global signal is quantified. The ensemble of results presented in this Thesis supports a very general picture of the nonequilibrium dynamics of slowly-driven fronts in open fractures: the lateral propagation of interfacial fluctuations is controlled by local mass conservation, through the lateral correlation length; and the advancement of the interface in the direction of propagation is controlled by the characteristic extent of the disorder d and by the mean front velocity.