Dissertations / Theses on the topic 'Water coupling'

A new closed-loop frequency-domain model is developed to incorporate the water hammer effect with pump rotordynamics, in order to investigate the sub-synchronous instability problem observed in a field pump. Seal flow-rate perturbations due to eccentricity are calculated from Soulas and San Andres's seal code. A complete transfer function matrix between rotor motion and reaction force due to pressure perturbation is developed in detail. Stability analysis with transfer-function'add-in' modules is conducted in XLTRC2. Seal clearances and the reaction force angle are found to be important in shifting natural frequencies and damping. The sub-synchronous instability observed in field is duplicated successfully with double-clearance seals.

The collaboration between the University of Barcelona and Acciona Agua was focused on optimizing greenhouses hydric resources. The functionality of a combined treatment had to be assessed, when applied to the discard stream of a recycling system of the Advanced Greenhouse leachates. The coupling consisted on an Advanced Oxidation Processes (AOP), photo-Fenton, based on hydroxyl radical oxidative potential, produced by the interaction between Fe2+ and H2O2, and a slow sand filtration column acting as a bioreactor. The recycling system will require the synergy of chemical and biological processes to be able to work efficiently with the particular characteristics of greenhouses effluents: high salinity content and the presence of pesticides. Two recycling strategies proposed by the project defined two conductivity thresholds that the coupled system should be able to cope with. The first strategy proposed a simple semi-closed system that recycled nutrient solution from the hydroponics crops until a maximum value of 11 mS•cm(-1), phytotoxicity limit. Part of the current was then diverted to be treated by the integrated system. The second strategy introduced reverse osmosis membrane technology that concentrated that diverted stream, sending the permeate for its reuse directly to the greenhouse, while the brine had to be treated by the coupled process. In this case the maximum level of salinity in the effluents could reach conductivities close to those for seawater, around 50 mS•cm(-1). The performance of photo-Fenton reaction was essayed in order to improve the knowledge regarding this treatment technique. On the first place, this AOP and the ozonation process were compared. Results shown that increasing toxicity of ozonation effluents confirmed the choice of photo-Fenton as the most adequate treatment for pesticide polluted effluents. Experimental design criteria allowed then to determine optimal working conditions depending on the content of the reaction media, and enabled to prove the existence of endogenous catalyst inhibition in the presence of fosetyl-Al. Salinity essays were finally performed, yielding positive results even for highest conductivity effluents. Those positive results were also reflected in the increase of the biodegradability of the treated effluents, what leaded to the next step of the research. Biocompatibility of pretreated effluents was essayed by means of sequencing batch reactors (SBR). These devices were used to show how photo-Fenton indeed increased biodegradability of the effluents, and how it grown until a certain point when more hydrogen peroxide did not lead to better results. They were also utilized to assess the biocompatibility of high salinity pretreated effluents, as a first step towards the coupling with the slow sand filtration at high conductivities. Results obtained were extremely encouraging, given that even for the highest salinity concentrations (10 and 50 mS•cm(-1)), the performance of the bioreactor achieved an organic content reduction for more than 80% of the loaded concentration, which compared to the 10-20% removal achieved by photo-Fenton, justifies the need of combining both treatments. Guided by those positive results, the load of the slow sand filtration column with different salinity pretreated effluents was performed. Also positive results were obtained. The achieved elimination of the organic content was more than 75% when loaded with 10 mS•cm-1 effluent, and the refractory fraction (the remaining organic matter that cannot be oxidized either by photo-Fenton reaction or by the biomass metabolism) was the lowest also for this high conductivity. Molecular biology tools, MTBs, used in this thesis were based on cloning and sequencing techniques of 16S rRNA genes. They allowed characterizing the bacterial population of one of the assessed SBRs and of the different loading stages of the slow sand filtration column. They showed how with the increase of salinity, the population in the slow sand filtration column loosed diversity, despite the fact that the performance of the column was still proficient. This fact stated how a very different microbial consortium could be developing the same functions as others. According to obtained results, it could be finally concluded that the coupling between photo-Fenton reaction and slow sand filtration column could be an effective treatment alternative for implementing the recycling strategies of hydroponics greenhouse leachates proposed by CENIT-MEDIODIA Project. For its part, MBTs were revealed as powerful tools to characterize microbial population and increase the understanding of the bioreactions taking part in bioremediation.
Esta tesis se enmarca en la colaboración entre el Departamento de Ingeniería Química de la Universidad de Barcelona y el Departamento de I+D de Acciona Agua S.A.U, en el marco del Proyecto CENIT- MEDIODIA (2007-2010). Esta iniciativa la componen un consorcio de empresas un consorcio de empresas y centros de investigación que unieron esfuerzos de innovación en el desarrollo de un nuevo concepto de Invernaderos Hidropónicos Avanzados. La colaboración entre la Universidad de Barcelona y Acciona Agua se centró en la optimización de los recursos hídricos de dichos invernaderos. Así se evaluó la funcionalidad de un tratamiento combinado que integrara un Proceso de Oxidación Avanzada (reacción foto-Fenton), y un reactor biológico (columna de arena de filtración lenta), aplicados a la corriente de desecho de un sistema de recirculación de lixiviados provenientes del nombrado invernadero avanzado. Las particularidades de dicho sistema de reciclado harían que el sistema combinado tuviese que trabajar con efluentes con alto contenido en pesticidas (metomilo, imidacloprid y fosetyl-Al, fueron escogidos para simular los lixiviados de invernadero) y conductividades entre 11 y 50 mS•cm-1. De este modo el principal objetivo del proceso integrado sería el de conseguir la máxima eliminación de los compuestos xenobióticos y de la carga orgánica que los acompañe en el efluente tratado. Así pues, la experimentación se llevó a cabo frente a tres aspectos relacionados con el sistema combinado: estudio de la reacción foto-Fenton, ensayos con biorreactores, y empleo de herramientas de biología molecular (MBT, en sus siglas en inglés) aplicadas a la caracterización de la biomasa desarrollada en los biorreactores ensayados. Según los resultados obtenidos, se llegó a la conclusión de que la combinación de la reacción foto-Fenton y la columna de filtración lenta podría ser una alternativa de tratamiento eficaz para la aplicación de las estrategias de reciclaje de los lixiviados hidroponía presentadas en Proyecto CENIT-MEDIODIA. Además, MBT se revelaron como poderosas herramientas para caracterizar la población microbiana de distintos biorreactores y las funciones que desempeñan.

Previous research has shown coupling of mechanical behaviour and water retention behaviour in unsaturated soils at a constitutive level, with degree of saturation (in addition to suction) influencing mechanical behaviour and volumetric strains influencing water retention behaviour. An innovative elasto-plastic modelling framework incorporating coupling of mechanical behaviour and water retention behaviour has been proposed by Wheeler, Sharma and Buisson (2003) for isotropic stress states. These authors presented a single constitutive model for both mechanical behaviour and water retention behaviour. They did not, however, fully validate the model against experimental results. The objectives of the current research included undertaking an experimental programme specifically designed to investigate the coupling between mechanical behaviour and water retention behaviour, and using experimental results to investigate the validity of the Wheeler et al. (2003) model. Developments and refinement of the model were also to be explored An experimental programme of suction-controlled testing was carried out on one-dimensionally compacted samples of speswhite kaolin in a single steel-walled triaxial cell and an isotropic cell. In addition to standard stress paths, such as isotropic loading, unloading, wetting, drying and shearing, many non-standard stress path tests were also performed. These produced a unique data set, providing evidence of aspects of behaviour never previously studied. In terms of constitutive model development, the Wheeler et al. (2003) model was extended to triaxial stress states, to include the role of deviator stress. In addition, bounding surface plasticity concepts were used to develop simple realistic water retention models for rigid or deformable unsaturated soils, and a new bounding surface plasticity version of the Wheeler et al. (2003) model was developed. However, a problem of theoretical inconsistency in the Wheeler et al. (2003) model was identified, which occurs if plastic volumetric strains are predicted while the soil is fully saturated. A simple, but rather unsatisfactory, solution to this inconsistency was identified, and further research is required to identify a more satisfactory solution. Codes were developed for stress point simulations with the original version of the Wheeler et al. (2003) model, the new bounding surface plasticity version of the model and the conventional Barcelona Basic Model. Simulations were performed of all the experimental tests performed in the current research, to explore the performance of the different models. Comparison of model simulations with experimental results showed that the Wheeler et al. (2003) model was able to represent basic concepts of the mechanical behaviour of unsaturated soils, but sometimes not with the same level of accuracy or flexibility as the Barcelona Basic Model. The Wheeler et al. (2003) model was however able to capture features of mechanical and water retention behaviour that could not be represented by the Barcelona Basic Model or by other conventional models for mechanical or water retention behaviour. The bounding surface plasticity version of the Wheeler et al. (2003) model sometimes produced improved predictions. There remained, however, specific aspects of behaviour that were not well matched by either versions of the Wheeler et al. (2003) model. Some of these may be solved in the future by refinement of specific constitutive equations within the Wheeler et al. (2003) model, but others appear more likely to be insoluble without a major change to the proposed modelling framework.

Introduction Combined thermal and fluid modeling is useful for design and optimization of cyclotron water targets. Previous heat transfer models assumed either a distribution of void under saturation conditions [1] or a static volumetric heat distribution [2]. This work explores the coupling of Monte Carlo radiation transport and Computation Fluid Dynamics (CFD) software in a computational model of the BTI Targetry visualization target [3]. In a batch water target, as the target medium is heated by energy deposition from the proton beam, a non-uniform density distribution develops. Production target operation is ultimately limited by the range thickness of the target un-der conditions of reduced water density. Since proton range is a function of target density, the system model must include the corresponding change in the volumetric heat distribution. As an initial attempt to couple the radiation transport and fluid dynamics calculations, the scope of this work was limited to subcooled target conditions. With the increasing availability of multi-phase CFD capabilities, this work provides the basis for extending these calculations to boiling targets where the coupling of the radiation transport and fluid dynamics is expected to be much stronger. Material and Methods The Monte Carlo radiation transport code MCNPX was used to create energy deposition data tallies from proton interaction with the target water and beam window. The beam was modeled as a Gaussian distribution with 50% transmission through a 10 mm diameter collimator. The energy deposition tally was translated into a 3-dimensional, point-wise heat generation table and supplied as an input to the CFD code ANSYS CFX. An iterative method was developed to couple the volumetric heat distribution from MCNPX to the fluid density distribution computed within ANSYS CFX. A 3-dimensional table of water density was exported from ANSYS CFX and imported into MCNPX. MCNPX was then used to calculate the heat generation rate (due to proton interactions) based on the assumed density profile. Applying the new heat generation profile to the ANSYS CFX model resulted in changes to the beam shape and penetration depth. The iterative scheme continued until converged values for density and heat generation rate were achieved. Monte Carlo methods are computationally ex-pensive due to the large number of particle histories needed to generate accurate results. CFD simulations are also computationally expensive due to the large number of mesh elements needed. Optimization methods were used for both MCNPX and ANSYS CFX to result in achievable solution times and memory requirements. Local mesh refinement in the beam strike area was necessary for convergence. This was achieved by extending the boundary layer of the mesh within the target water domain deeper into the fluid. This allowed for better resolution within the beam strike area without significantly increasing the expense in the remainder of the fluid domain. Additionally, direct simulation of the cooling water domain was decoupled from the computational model during the iterative process. Heat transfer coefficients from the first iteration were applied as a boundary condition for subsequent iterations. Once the beam and density distributions reached convergence, the beam data was applied to a high fidelity “full” model, which included the cooling water domain as well as increased particle histories in MCNPX. Results and Conclusions The target was initially modeled assuming a 10 μA beam of 18 MeV protons into uniform density target water with operating pressure of 400 psi. These conditions resulted in predicted maximum temperatures below the saturation temperature. The final converged beam data was compared to the original (uniform density) beam data. As expected, the density-dependent beam penetrates farther into the target water than when a uniform density is assumed. The density-dependent beam has a broader Bragg peak region with a lower maximum heat generation rate than the original beam. A line plot of the volumetric heat generation rate through the center of the beam is shown in FIG. 2. Even though the maximum volumetric heat generation rate was lower, the density-dependent beam resulted in a higher maximum fluid temperature. Experiments were performed with the visualization target on an IBA 18/9 cyclotron, and video was recorded for a range of target operating conditions. Analysis of the video recordings from the experiment gives a peak fluid velocity in the target chamber of roughly 5–10 centimeters per second with a 10 A beam current. The velocities predicted by the CFD model are within the same range. There is also good agreement be-tween proton beam range between the experiment and model. The effective proton range can be seen in FIGURES 3 and 4. Future work will include applying the coupling technique for two-phase boiling conditions and to gas targets. If successful, this method should be a powerful tool for design and optimization of liquid and gas targets.

This thesis covers the subject of deriving and solving the system of partial differential equations known as the Shallow Water Equations (SWE), and coupling the solutions of this equation system to a simplified model of a surfer - or any floating object, with the right choice of parameters. The SWE are generally used to analyze fluid movement on shallow areas, such as ocean waves nearing the shore, and are derived from the Navier-Stokes equations and restricted to conservation of mass and momentum in a fluid. In this project the solution to these equations was made to yield a propagating wave profile. From the solution, the steepening behaviour and the slow propagation speed of shallow water waves are explained - properties that are necessary for wave surfing. The SWE was solved with the first order accurate finite volume scheme known as the Lax Friedrichs Method (LxF), and a surfable wave is created with a suitable set of initial- and boundary conditions parameter values. LxF is also derived from the discretization of the conservation form of the SWE. The solver can also handle a non-horizontal seabed - bathymetry, but does not take into consideration friction from the seabed. A "surfer" was created as a point mass acted on by three forces: hydrodynamic drag, gravity and buoyancy. The "surfer" is made to move realistically by simulating the effect of these forces and updating position and velocity of the surfer accordingly. The surfer is made to move along with the wave.

Thesis (M.S.)--Joint Program in Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science; and the Woods Hole Oceanographic Institution), 1994.
Includes bibliographical references (p. 57-58).
by Denis Peregrym.
M.S.

Thesis (S.M. in Mechanical Engineering and S.M. in Ocean Engineering)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2005.
Includes bibliographical references (p. 159-164).
Air-water interaction flow between two parallel flat plates, known as Couette flow, is simulated by direct numerical simulation. The two flowing fluids are coupled through continuity of velocity and shear stress condition across the interface. Pseudo-spectral method is used in each flow subdomain with Fourier expansion in streamwise and spanwise directions and finite difference in vertical direction. Statistically quasi-steady flow properties, such as mean velocity profiles, turbulent intensities, Reynolds stress and turbulent kinetic energy (TKE) budget terms show significant differences between air-water interface turbulence near the water side (IntT-w) and wall-bounded turbulence(WT) while there are some similarities between IntT-w and free surface turbulence (FST). Due to the velocity fluctuation at the interface, water side near interface turbulence flow (IntT-w) is characterized with a thinner viscous sub-layer and decreased intercept parameter B in log-law layer, strengthened Reynolds stress and eddy viscosity, together with a stronger production term, decreasing-then-increasing dissipation term and negative turbulent diffusion term in TKE budget.
(cont.) Abundant physical phenomena exist on the water side turbulent flow with four major types of three-dimensional vortex structures identified near the interface by variable-interval spacing averaging (VISA) techniques. Each type of vortex structures is found to play an essential role in the turbulent energy balance and passive scalar transport.
by Song Liu.
S.M.in Mechanical Engineering and S.M.in Ocean Engineering

Efficient methods for the numerical simulation of the shallow water equations are important for understanding flooding events and related phenomena. One such approach is to couple 2D shallow water floodplain flow model to 1D Saint Venant's open channel flow model. Currently, these methods are mostly designed in horizontal fashion, meaning that the separate models are coupled at the horizontal interface between the 2D and 1D regions. These methods cannot be adapted for different flooding scenarios and are not able to compute a 2D flow structure within the channel without solving the full 2D models at all times. In this thesis, we propose coupling methods that aim to overcome these limitations. First, we propose the horizontal coupling method (HCM) in the lines of existing methods. The HCM follows the derivation of coupling terms proposed in [Marin and Monnier, 2009] but we arrive at a slightly different coupling term. Then, a discrete coupling term in closed form and the computation of two lateral discharges over channel cross sections, are proposed. Next, we propose a completely new approach to model coupling; we call it the vertical coupling method (VCM). The VCM is based on vertically partitioning the channel flow into two layers. Flows in the lower and upper layers are assumed to be 1D and 2D respectively, and the appropriate flow models derived. By preserving conservation and 1D consistency, the numerical algorithm for coupling the two layer models, is formulated. We show that (i) both the HCM and the VCM are well-balanced and preserve the no-numerical flooding property, (ii) that the VCM adapts to the flow situation: solving the upper layer 2D model only if flooding. Numerical experiments show that both methods provide promising results and that the VCM is able to compute the 2D flow structure within the channel, whenever flooding. We also discuss (without numerical details) how the VCM is a family of methods and some areas of possible further research work are suggested.

Abstract In this thesis nuclear magnetic resonance (NMR) and magneto-optical rotation (MOR) parameters are investigated for water, paying special attention to the effect of solvation from gaseous to liquid phase. Nuclear magnetic shielding and quadrupole coupling tensors of NMR spectroscopy are studied for gaseous and liquid water. Liquid state is modelled by a 32-molecule Car-Parrinello molecular dynamics simulation, followed by property calculations for the central molecules in clusters cut out from the simulation trajectory. Gaseous state is similarly represented by a one-molecule simulation. Gas-to-liquid shifts for shielding constants obtained this way are in good agreement with experiments. To get insight into the local environment and its effect on the properties the clusters are divided into groups of distinct local features, namely the number of hydrogen bonds. The analysis shows in detail how the NMR tensors evolve as the environment changes gradually from the gas to liquid upon increasing the number of hydrogen bonds to the molecule of interest. The study sheds light on the usefulness of NMR experiments in investigating the local coordination of liquid water. To go a bit further, the above mentioned NMR parameters along with the spin-spin coupling constant are examined for water dimer in various geometries to have insight into solvation and hydrogen bonding phenomena from bottom to top. Characteristic changes in the properties are monitored as the geometry of the dimer is systematically varied from very close encounter of the monomers to distances and orientations where hydrogen bonding between monomers ceases to exist. No rapid changes during the hydrogen bond breaking are observed indicating that the hydrogen bonding is a continuous phenomenon rather than an on-off situation. However, for analysis purposes we provide an NMR-based hydrogen bond definition, expressed geometrically, based on the behaviour of the NMR properties as a function of dimer geometry. Our definition closely resembles widely used definitions and thus reinforces their validity. Magneto-optical rotation parameters, the nuclear spin optical rotation (NSOR) and the Verdet constant, are computed for gaseous and liquid water, in the same manner as the NMR properties above. Recent pioneering experiments including NSOR for hydrogen nuclei in liquid water and liquid xenon have demonstrated that this technique has a potential to be a useful new probe of molecular structure. We reproduce computationally, applying a first-principles theory developed recently in the group, the experimental NSOR for hydrogen nuclei in liquid water, and predict hydrogen NSOR in gaseous water along with the oxygen NSOR in liquid and gaseous water. NSOR is an emerging experimental technique that needs interplay between theory and computation for validation, steering and insight.

When properly designed, hypolimnetic aeration and oxygenation systems can replenish dissolved oxygen in water bodies while preserving stratification. A comprehensive literature review of design methods for the three primary devices was completed. Using fundamental principles, a discrete-bubble model was first developed to predict plume dynamics and gas transfer for a circular bubble-plume diffuser. This approach has subsequently been validated in a large vertical tank and applied successfully at full-scale to an airlift aerator as well as to both circular and linear bubble-plume diffusers. The unified suite of models, all based on simple discrete-bubble dynamics, represents the current state-of-the-art for designing systems to add oxygen to stratified lakes and reservoirs. An existing linear bubble plume model was improved, and data collected from a full-scale diffuser installed in Spring Hollow Reservoir, Virginia (U.S.A.) were used to validate the model. The depth of maximum plume rise was simulated well for two of the three diffuser tests. Temperature predictions deviated from measured profiles near the maximum plume rise height, but predicted dissolved oxygen profiles compared very well to observations. Oxygen transfer within the hypolimnion was independent of all parameters except initial bubble radius. The results of this work suggest that plume dynamics and oxygen transfer can successfully be predicted for linear bubble plumes using the discrete-bubble approach. To model the complex interaction between a bubble plume used for hypolimnetic oxygenation and the ambient water body, a model for a linear bubble plume was coupled to two reservoir models, CE-QUAL-W2 (W2) and Si3D. In simulations with a rectangular basin, predicted oxygen addition was directly proportional to the update frequency of the plume model. W2 calculated less oxygen input to the basin than Si3D and significantly less mixing within the hypolimnion. The coupled models were then applied to a simplified test of a full-scale linear diffuser. Both the W2 and Si3D coupled models predicted bulk hypolimnetic DO concentrations well. Warming within the hypolimnion was overestimated by both models, but more so by W2. The lower vertical resolution of the reservoir grid in W2 caused the plume rise height to be over-predicted, enhancing erosion of the thermocline.
Ph. D.

Sound does not transmit well across the interface of two media. Therefore, most organisms communicate using one medium. Some anurans vocalize at the interface of air and water, though reception of these vocalizations is generally unknown. The túngara frog ( Engystomops pustulosus ) may be the first anuran to have evidence suggesting simultaneous acoustic communication both above and below the air-water interface. This thesis addresses whether the female túngara frog would be receptive to underwater acoustic signals and if males project their advertisement calls at biologically relevant intensities underwater. Females floated and swam with their eardrums and body walls constantly submerged. Using laser Doppler vibrometry, peak vibrations of female eardrums were found to be centered at about 3.5 kHz in air, but dropped to about 1.4 kHz underwater. The peak velocity of the eardrum was about 0.2 mm/s in air and 0.04 mm/s in water when stimulated with tones at 80 dB relative to 20 µPa. Males projected their advertisement calls with a sound pressure level of 121 dB (at 10 cm, re. 20 µPa) in water and 98 dB (at 10 cm, re. 20 µPa) in air. In relation to air, the dominant frequency of the advertisement call (0.8 kHz) was the most intense spectral band underwater whereas the dominant frequency of the chuck (2.5 kHz in air) was less intense. The advertisement signal for the male túngara frog was broadcasted underwater with more energy than in air at its main frequencies. Female eardrums were sensitive to frequencies within the male advertisement call both in air and in water, if the frequencies were transmitted at amplitudes plausible to be encountered in nature. These results strengthen the available evidence of underwater communication, and indicate the presence of auditory specializations in the acoustic communication of this species.

Linkages between nutrient limitation in the Masinga reservoir in Kenya and nutrient supply from its catchment were approached by the study of phosphorus dynamics. The pattern of rainfall and the warm temperatures were characteristic of tropical climates and determined the state of phosphorus in the soil and its delivery to aquatic systems. Mechanism of phosphorus transport were related to adsorption/desorption equilibria between orthophosphate and metal (hydr)oxides fixed at the surface of clay particles. The monitoring of suspended solids, total and dissolved phosphorus, dissolved nitrogen, conductivity and silicate during a one and a half year field study in a selected subcatchment highlighted patterns of nutrient mobilization and transport from rivers to the reservoir. Yearly budgets of suspended sediment and total phosphorus export from the subcatchment yielded respectively 161 t/km2/ann and 109 kg/km2/ann for a yearly runoff of 346 mm. Phosphorus loading was contemporaneously monitored in the reservoir. The annual loading was 10.4 gP/m2 (1993) and did not result in the establishment of eutrophic conditions. Constant high temperatures, high concentrations of suspended solids and the occurrence of a deep water outlet combined to generate density flows. Part of the load was sedimented in well oxygenated, shallow, upper sections of the reservoir while the rest exited through the deep water uptake and was transported to other reservoirs downstream. The study of phytoplankton biomass and primary production in relation to nutrient availability revealed that periods of phosphorus limitation alternate with light limitation. The phytoplankton assemblage responds with an alternation of periods dominated by filamentous Cyanophytes (Cylindrospermopsis africana, Planktolyngbya limnetica) and pennate diatoms (Achnanthes sp., Synedra ulna). Gross primary production varied between 0.03 and 1.43 g C/m2/d. A survey of four other reservoirs in the cascade suggested that bottom sediments are a phosphorus sink.

A majority of carbon in freshwater and marine ecosystems is in the form of ultraplankton, heterotrophic and autotrophic plankton &<&5 &\mu&m including heterotrophic bacteria, Prochlorococcus, cyanobacteria, and autotrophic eucaryotes. However, ultraplankton and subsequently microbial food webs have yet to be incorporated into models of benthic-pelagic coupling despite the preponderance of macroinvertebrates with the capacity to feed on ultraplankton. I have examined the role of microbial food webs in benthic-pelagic coupling in three ecosystems: Lake Baikal, Siberia, Russia; Gulf of Maine, Northwest Atlantic Ocean; and Conch Reef, Florida Keys, USA. Using sponges as a model organism and in situ measurements, I have quantified (1) suspension feeding on ultraplankton and (2) release of dissolved inorganic nitrogen (DIN) and phosphorus (DIP) resulting in direct evidence that benthic macroinvertebrates do occupy the level of primary consumer within the microbial food web. Dual-beam flow cytometry was employed to quantified sponge suspension feeding on five types of ultraplankton: heterotrophic bacteria, Synechococcus-type cyanobacteria, autotrophic picoplankton &<&3 &\mu&m, autotrophic eucaryotes 3-10 &\mu&m, and in marine ecosystems Prochlorococcus. Grazing by the freshwater sponges Baikalospongia intermedia and B. bacilliferia and the boreal marine sponge, Mycale lingua, was unselective for all types of ultraplankton with efficiencies ranging from 63-99%. This is the first time that grazing on Synechococcus-type cyanobacteria and Prochlorococcus by macroinvertebrates has been quantified in freshwater and marine ecosystems. Conversely, the coral reef sponges Ircinia felix and I. strobilina release significant amounts of DIN and DIP as a result of grazing on procaryotic plankton. Using a general model for organism-mediated fluxes, it is conservatively estimated that through active suspension feeding sponges in Lake Baikal retain 1.97 g C day&\sp{lcub}-1{rcub}& m&\sp{lcub}-2{rcub}& and M. lingua retains 29 mg C day&\sp{lcub}-1{rcub}& m&\sp{lcub}-2{rcub}& while at Conch Reef sponges released 204 &\mu&mol DIN day&\sp{lcub}-1{rcub}& m&\sp{lcub}-2{rcub}& and 48 &\mu&mol DIP day&\sp{lcub}-1{rcub}& m&\sp{lcub}-2{rcub}&. A majority of the carbon retained at all three locations was from procaryotic cell types suggesting that ultraplankton are an important overlooked component of benthic-pelagic coupling.

This thesis deals with Sector coupling problematics. First, it deals with the development and present situation in the generation and consumption of electric power and the development and present situation in the extraction and consumption of natural gas in the Czech Republic and in the European union. Further, the thesis deals with Sector coupling, this concept is explained, and it is adumbrated what questions it deals with. Then, the technologies that can be achieved in the future of Sector coupling are introduced. Pilot projects of these technologies are presented as part of the discussion about these technologies. Finally, a consideration of the future use of Sector coupling technologies in the Czech Republic is given.

The main objective of this research was to develop and utilize a coupled surface water groundwater model to simulate hydrological responses of watersheds. This was achieved by coupling the U.S. Geological Survey (USGS) groundwater flow model, MODFLOW, and the rainfall runoff model, TOPMODEL, in one case study and coupling MODFLOW with a networked version of TOPMODEL called TOPNET in another case study. The model coupling was achieved using the InCouple approach, which utilizes Potential Coupling Interfaces (PCIs) that are abstractions from model flow diagrams that expose only those aspects of a model relevant to coupling. Coupling the rainfall-runoff models to MODFLOW involved development of a routine relating the spatial discretization of MODFLOW to TOPMODEL and similarly MODFLOW to TOPNET and development of a feedback scheme where groundwater and surface water interact in the soil zone. The key coupling concept was replacing the wetness index-based depth-to-water table concept of TOPMODEL with the groundwater heads simulated by MODFLOW. In the MODFLOW-TOPMODEL coupling, using data for the Tenmile Creek watershed, for the period, 1968 to 1972, it was concluded that the coupled model was able to continuously simulate the stream flow. However, the coupled model under predicted stream flow and did not agree well with observations in a point wise comparison. A mean coefficient of efficiency of 0.54 was obtained between simulated and measured stream flow. Only 24% of received precipitation was observed as baseflow and this shows that there is limited interaction between surface water and groundwater in the watershed. It was demonstrated using the coupled model that the lateral flow processes and the interactions between groundwater and surface water have a major importance for the water balance. For the Big Darby watershed, for the period 1992 to 2000, the coupled model adequately predicts the stream and groundwater flow distribution in the watershed. After model calibration, simulated groundwater showed the greatest residual variance, attributed to model error and uncertainty in model parameters. Model fit efficiencies of 0.61 and 0.69 were obtained for simulating stream flow measured at two gaging stations. The overall watershed hydrologic budget also showed small mass balance errors using the coupled model. However, the study also shows the need for further research in regard to constraining the groundwater recharge parameter which links the models.

The making and breaking of O-O bonds has implications ranging from artificial photosynthesis and water oxidation to the use of O₂ as a selective, green oxidant for transformations of small molecules. Oxidative generation of O₂ from coupling of two H₂O molecules remains challenging, and well defined systems that catalytically evolve O₂ are exceedingly rare. Recent theoretical studies have invoked metal oxyl radicals (L[subscript n]M=O*) containing a singly occupied M-O π-type orbital as precursors to O-O bond forming events in both biological and synthetic water oxidation catalysts. However, the lack of stable metal oxyl complexes makes it difficult to explore and understand this hypothesis. The activation of dioxygen (breaking of O-O bonds) to produce terminal metal oxos also remains a challenge. There is an inherent kinetic barrier to the spin-forbidden reactions of triplet dioxygen, and features that engender selective O₂ reduction are not easily transferable from system to system. The primary thrust of this thesis work has been to elaborate new methods to generate well-defined metal oxyl radicals for studies of their reactions in radical bond-forming reactions similar to the radical coupling hypothesis of water oxidation. A library of >20 5- and 6-coordinate high-valent oxorhenium complexes containing redox-inert and redox-active ligands has been prepared. The complexes containing redox-active ligands have shown the ability for ligand-mediated radical coupling reactions. Mechanistic studies of bimetallic O₂ homolysis (the microscopic reverse of water oxidation) and nitroxyl radical deoxygenation at five-coordinate oxorhenium(V) reveal that, in both net 2e⁻ reactions, coupling to a redox-active ligand lowers the kinetic barrier to the reaction by facilitating formation and stabilization of 1e⁻ oxidized intermediates. Coordinatively unsaturated high-valent oxorhenium complexes containing redox-active ligands direct bond-forming reactions towards the metal center. This is undesirable towards the goal of forming O-O bonds. To address this problem coordinatively saturated Re(V) and Re(VII) complexes were prepared. Oxidation of these species by chemical oxidants allowed for the isolation of "masked" oxyl species. These complexes showed reactivity towards Si and trityl radicals to produce new Si-O and C-O bonds, whereas their closed-shell congeners were inert. We have successfully developed a method for the preparation and isolation of "masked" oxyl radicals and shown their utility in ligand-mediated radical coupling reactions.

We report results for the development of a flow-through integrated cavity absorption meter (ICAM.) Absorption measurements have been made with 2% or less change in the signal in the presence of up to 10 m-1 of scattering in the medium. The operating range of the ICAM ranges from 0.004 m-1 to over 40 m-1 of absorption. This range allows one to use a single instrument to measure the absorption from sediment laden rivers out to the cleanest of ocean waters. Further, the ICAM signal has been shown to be independent of the flow rate and turbulence in the medium. In addition we report the development of a diffuse reflector which, to our best knowledge, has the highest measured diffuse reflectivity of 0.998 at 532 nm and 0.996 at 266 nm. We also show that the average distance a photon travels between successive reflections in an integrating cavity of arbitrary shape is four times the volume divided by the surface area, 4 V/S. Further, for a cavity which is formed by planes tangent to an inscribed sphere and which maintains a homogeneous and isotropic field, the average distance traveled by a photon between successive reflections is equal to 4 V/S of the inscribed sphere. Thus, each cavity has the same ratio of V/S as the inscribed sphere. These advances lead to an increase in the sensitivity of absorption spectroscopy. The sensitivity approaches that of cavity ring down spectroscopy (CARS), without the adverse scattering effects traditionally associated with CARS.

With the growing use of membranes in the water industry, different methods for using membranes to treat water is still occurring. Enhancing membrane performance is generally performed with extensive pretreatment methods before the feedwater is filtered by the membrane. With the utilization of direct membrane filtration (DF), no pretreatment is performed and the membrane is exposed to raw wastewater. While this may suggest that membrane performance and permeate quality would suffer in the process, DF testing with a 0.03 µm ultrafiltration PVDF membrane showed that relatively high membrane flux was sustained while producing a high quality effluent. Due to the rejection of the membrane, a highly concentrated fraction of the wastewater, which is significantly reduced in volume but high in solids and organic strength, is obtained and can be treated in other ways. A process is proposed to treat municipal wastewater by coupling a DF system with an anaerobic membrane bioreactor (AnMBR). AnMBRs generally treat industrial strength wastewater, which is high in chemical oxygen demand (COD), and may struggle with domestic wastewater, which is generally considered low strength in terms of COD. By coupling the DF with an AnMBR, the DF-AnMBR can be used to treat the low strength domestic wastewater. The DF portion can handle the bulk of the liquid fraction, while the highly concentrated fraction of wastewater is treated by the AnMBR stage, thus improving the energy profile of the AnMBR and enhancing performance. A series of flow and mass balance equations for the combined DF-AnMBR was developed, and used to shed insight on design parameters relevant to this novel treatment process. Since membrane fouling occurs gradually over weeks or months, it is difficult to systematically determine how processes changes may affect membrane performance. Hence, a method to rapidly determine the fouling propensity of wastewater was desired. The modified fouling index (MFI) was previously developed to test the fouling propensity of feedwater for seawater RO desalination, but has not been applied to membrane filtration of wastewater. The MFI method was adapted and used to test the fouling propensity of various treatment streams in the DF-AnMBR system, including raw domestic wastewater, concentrated domestic wastewater (20X by DF), and liquor from an active AnMBR. The effect of powdered activated carbon (PAC) on fouling propensity was also investigated. Raw wastewater had a fouling potential of about 25% of the AnMBR MFI, and with the utilization of PAC the fouling potential was further decreased to nearly 50% of the original fouling potential. The DF concentrated stream had a higher MFI value than liquor from the AnMBR, but presumably some of organics contributing to fouling would be degraded in the AnMBR. This study demonstrated that DF of raw wastewater is feasible, and the combined use of DF and AnMBR is highly promising.

The increasing water demand coupled to the depletion of natural water sources has raised the need to investigate and develop in wastewater treatment and reuse. Even more, the application of circular economy principies to water cycle has highlighted the need to see wastewater as a source of water and resources. Therefore, hybridization of already developed technologies can help achieve circular economy goals. Moreover, these hybrid systems that take the best of each technology are capable to gain to the limitations of current conventional treatments. Thus, in this thesis, different hybrid systems have been developed and tested (at bench and pilot scales) for wastewater treatment, both urban and industrial. On one hand, three upflow anaerobic sludge blanket (UASB) reactors with different configurations: flocculent biomass, flocculent biomass and membrane solids separation and granular biomass and membrane solids separation (UASB-AnMBR), were operated to compare start-up, solids hydrolysis and effluent quality. The challenges of this work were both the low temperature and the low COD content. A really quick start-up was observed for the three reactors and was attributed to the previous acclimation of the seed sludge. The UASB configurations with membrane retained the solids in the reactor increasing solids hydrolysis efficiency. Moreover, flocculent biomass promoted slightly higher hydrolysis than granular one. Therefore, a configuration based on flocculent UASB-AnMBR was appropriate for the treatment of urban wastewater with low COD content at 10°C. ' On the other hand, a single-stage AnMBR for the treatment of cheese whey and its co-digestion with cattle slurry was investigated with the aim of potentially recovering water and energy. High COD removal (91% ± 7%) was achieved with a biogas production of 0.2-0.9 m3 biogas/kg COD removed. Therefore, high energy recovery could be obtained when using this process with a mean value of 2.4 kWh/kg COD removed. Although energy recovery was directly validated, severallimitations were detected regarding water reuse. Those limitations comprised high salt concentration in the permeate, which should be removed prior to its reuse. Moreover, petrochemical wastewater pre-treatment was optimised with the final objective of water recycling. lt consisted in a coagulation-flocculation (CF) step followed by a moving bed biofilm reactor (MBBR) aimed to decrease suspended solids (SS) and organic content. In this case, only the first part of the hybrid system was optimised, membrane units were not included in this work. CF tests showed a decrease in wastewater turbidity but no significant DOC removal. Wastewater was then treated by MBBR. In MBBR, high sCOD removal efficiency (80-90%) was maintained. The MBBR proved to be also effective when treating raw wastewater as well as when feed wastewater effluent proportions were changed. The obtained results showed that MBBR was a suitable technology for petrochemical wastewater pre-treatment. Finally, a novel treatment strategy for landfillleachate aimed to decrease its environmental impact was studied. The system consisted in a membrane bioreactor (MBR) pre-treatment aimed to remove COD, N and SS. lt was followed by a combined reverse osmosis-electrodialysis reversa! (RO-EDR) treatment aimed to remove salts and decrease brine volume. MBR decreased inorganic carbon by 92 ± 8% and achieved N removal of 85%. RO achieved a recovery of 84% and rejections of above 95%. EDR unit treating RO brine achieved a recovery of 67%. Thus, average recovery of the whole system was above 90%. lt is important to highlight that end-of-life RO regenerated membranes were used in this study. This fact, together with the low volume of brine (<10%) helped decrease the environmental impact of leachate treatment. Hence, this thesis was conducted from an applied research approach, aimed to reduce the gap between basic technology development and industrial implementation.
La creixent demanda d'aigua i l'esgotament de les fonts naturals ha generat la necessitat d'investigar i desenvolupar nous tractaments d'aigua així com la seva reutilització. L'aplicació dels principis de l'economia circular al cicle de l'aigua ha posat de manifest la necessitat de percebre les aigües residuals com a font d'aigua i recursos. Així dones, la hibridació de tecnologies ja desenvolupades pot ajudar a complir els objectius de l'economia circular. A més, aquests sistemes híbrids són capaços de superar les limitacions deis tractaments convencionals. Així dones , en aquesta tesi, s'han desenvolupat i provat diferents sistemes híbrids (a escala de banc de proves i pilot) per al tractament d'aigües residuals urbanes i industrials. D'una banda, s'han operat tres configuracions de reactors UASB (Upflow Anaerobic Sludge Blanket) per comparar la posada en marxa, la hidrólisi dels sòlids i qualitat de l'efluent. Aquestes configuracions eren: biomassa flocular, biomassa flocular amb separació per membrana i biomassa granular amb separació per membrana (UASB-AnMBR). Els reptes d'aquest treball han estat tant la baixa temperatura com el baix contingut en DQO. La posada en marxa ha estat molt ràpida per als tres reactors, atribuïda a l'aclimatació prèvia dels fangs . Els resultats mostren que una configuració basada en UASB-AnMBR amb biomassa flocular ha estat adequada peral tractament d'aigües residuals urbanes amb baix contingut en DQO a 10°C. D'altra banda, s'ha investigat un AnMBR per al tractament de xerigot i la seva codigestió amb purí amb l'objectiu de recuperar aigua i energia . S'ha aconseguit una elevada eliminació de DQO (91% ± 7%) amb una producció de biogàs de 0,2 a 0,9 m3 de biogàs/kg de DQO eliminada. Per tant, es calcula que es podria obtenir una elevada recuperació d'energia amb un valor mitja de 2,4 kW/kg de DQO eliminada. Tot i que s'ha validat directament la recuperació d'energia, s'han detectat diverses limitacions en relació amb la reutilització de l'aigua. Aquestes limitacions inclouen una elevada concentració de sal en el permeat, que caldria eliminar abans de la seva reutilització. A més, s'ha optimitzat el pretractament pera aigües residuals petroquímiques amb l'objectiu de reciclar l'aigua. Aquest ha consistit en una coagulació-floculació (CF) seguida d'un MBBR (Moving Bed Biofilm Reactor) per tal de disminuir els sòlids en suspensió (SS) i el contingut orgànic. En aquest cas, només s'ha optimitzat la primera part del sistema híbrid ja que no s'han inclòs les etapes de membrana en aquest treball. Les proves de CF han mostrat una disminució de la terbolesa de les aigües residuals sense eliminació significativa de DQO. Aquest efluent s'ha tractat per MBBR. A I'MBBR s'ha mantingut una elevada eficiència d'eliminació de DQOs (80-90%). Els resultats obtinguts mostren que el MBBR és una tecnologia adequada per al pretractament de les aigües residuals petroquímiques. Finalment, s'ha estudiat una nova estratègia de tractament de lixiviats d'abocador per disminuir el seu impacte ambiental. El sistema s'ha basat en un pretractament amb bioreactor de membrana (MBR) pera l'eliminació de DQO, Ni SS seguit d'un tractament combinat d'osmosi inversa-electrodiàlisi reversible (01-EDR) pera l'eliminació de sals i disminució el volum de salmorra . L'MBR ha disminuït el carboni inorgànic en un 92 ± 8% i ha aconseguit una eliminació de N del 85%. Gracies a les etapes d'OI i EDR, la recuperació mitjana de tot el sistema ha superat el 90%. És important destacar que en aquest estudi s'han utilitzat membranes regenerades d'OI al final de la seva vida útil. Aquest fet, juntament amb el baix volum de salmorra {<10%) ha contribuït a disminuir !'impacte ambiental del tractament de lixiviats. Per tant, aquesta tesi s'ha dut a terme des d'un enfoc de recerca aplicada, amb l'objectiu de reduir la bretxa entre el desenvolupament tecnològic basic i la implementació industrial

Grand Coulee Dam created Franklin D. Roosevelt Lake as part of the Columbia Basin Project. Located in northeastern Washington State, the Project provides economically important hydropower (19 billion kilowatt hours per year), irrigation (225,000 ha), flood control, and sport fishing ($5 to 20 million annually). A good system understanding aids in balancing these beneficial uses for the 230 km long reservoir. The reservoir's atypical 45-day mean residence time is much shorter than a typical lake, and much longer than for a riverine dam. The spring freshet requires drawdowns of 15 to 20 m for flood control—the driving characteristic of reservoir operations. A physically based two-dimensional hydrodynamic and water quality model, CE-QUAL-W2 Version 3.5 (Cole and Wells, 2006), is coupled with a fish bioenergetics model based on the Stockwell and Johnson model (1997, 1999) to examine the effects of hydrodynamics on the reservoir algae-zooplankton-kokanee food web. This model was applied and calibrated to Lake Roosevelt with model improvements of multiple zooplankton compartments and zooplankton omnivory. Calibration parameters included temperature, dissolved oxygen, nutrients, algae, and zooplankton. The fish bioenergetics model is applied over the entire reservoir model space to generate a spatial and temporal fish growth potential distribution. The fish model refinements include sub-daily time-steps and an optimized vertical foraging strategy. The linked model suggests that kokanee fish growth potential is seasonally limited by both warm water and prey densities. While the lake ecology is significantly affected by the reservoir operations in general, the pelagic fish growth potential did not appear sensitive to minor changes in reservoir operations. However, the model suggests that the advantageous foraging locations shift seasonally and that optimal foraging strategies are dependent on fish size.

Els reactius de iode hipervalent són oxidants eficients en diverses transformacions oxidatives. Kita havia utilitzat el sistema PIFA/BF3·Et2O per assolir acoblaments oxidatius arè-arè. El nostre grup va extendre aquesta metodologia a l’acoblament oxidatiu directe de quatre components (four-component direct oxidative coupling) en el que estaven implicats binaftalè i arens. Seguint amb el nostre interés en aquest tema, en aquesta tesi hem preparat diversos tris-, tetra- i hexanaftalens arilats, compostos que tenen potencial interès en les àrees dels colorants i dels dispositius òptics orgànics. Dins també del tema dels organoiodans hipervalents, Koser havia emprat una quantitat estequiomètrica de PhI(OH)(OTs) en la formació oxidativa d’enllaços C-O. Atès que el reactiu hipervalent reverteix al correspondent iodoarè, el procés fóu millorat posteriorment per Ochiai mitjançant l’ús de quantitats catalítiques de iodurs d’aril en presència d’un oxidant terminal, de manera que les espècies hipervalents es generaven in situ. En aquesta tesi hem desenvolupat iodurs d’aril immobilitzats pel mètode sol-gel com a catalitzadors reciclables en l’α-tosiloxilació de cetones. Inesperadament, una sílica híbrida derivada de (3-iodopropil)trietoxisilà també va mostrar activitat catalítica. A partir d’aquí, posteriors investigacions van revelar que els iodoalcans poden actuar també com a pre-catalitzadors en aquest procés oxidatiu. En presència d’un oxidant (m-CPBA), els iodoalcans experimenten una degradació oxidativa per donar espècies catalítiques inorgàniques (probablement IO— o IO2-- ). La sobreoxidació de l’espècie inorgànica formada in situ produeix la desactivació del catalitzador i la formació d’una nova fase de l’àcid iódic (HIO3), no descrita fins ara, estructura que s’ha resolt ab initio a partir de dades de difracció de raigs-X de pols. Per altra banda, les nanopartícules (NPs) metàl.liques són molt útils en catàlisi degut a les particulars propietats derivades de la seva mida i morfología. Es requereix un agent estabilizant (S) per evitar l’aglomeració de les NPs i controlar la reactivitat en la superfície. En aquesta tesi s’ha dissenyat i sintetitzat un nou estabilitzant amb elevat contingut de nitrogen i cadenes de PEG, per preparar NPs d’or(0) i de rodi(0) solubles en aigua. Variant la relació molar S/Rh es controla la mida i la morfologia de les NPs de Rh(0), des de petits clústers a nanoflowers. Un fenòmen similar s’ha observat en les NPs d’Au(0), on la morfologia varia des de petites esferes fins a nanotadpoles i la mida depèn de la quantitat d’estabilitzant. Els nanomaterials s’han caracteritzat completament. Les NPs de Rh en forma de flor han mostrat bona activitat catalítica en la hidrosililació estereoselectiva d’alquins interns i s’han pogut reciclar fàcilment, mentre que les NPs d’Au són catalitzadors eficients i reciclables en la reducció selectiva de nitroarens a les corresponents anilines en aigua a temperatura ambient.
Hypervalent iodine reagents are known to act as efficient oxidants in a range of oxidative transformations. Kita and coworkers previously used the PIFA/BF3·Et2O system to achieve the dehydrogenative arene-arene coupling. Our group extended this methodology to a direct oxidative coupling of four molecules involving binaphthalene and arenes. Following the group’s work in this field, we have prepared in this doctoral work new arylated tris-, tetra- and hexa-naphthalene oligomers, which constitute compounds of potential interest in the field of dyes and organic optical devices. As a separate topic on hypervalent organoiodanes, Koser et al. used stoichiometric amounts of PhI(OH)(OTs) in the oxidative formation of C-O bonds. Given that the hypervalent reagent reverts to the parent iodoarene, the process was made catalytic by Ochiai using sub-stoichiometric quantities of the aryl iodides in the presence of a terminal oxidant, with the hypervalent species being generated in situ. In this thesis we have developed recyclable sol-gel immobilized aryl iodides for the catalytic α-tosyloxylation of ketones. Unexpectedly, a hybrid silica derived from (3-iodopropyl)triethoxysilane was also catalytically active. Further investigations revealed that, unexpectedly, even iodoalkanes can act as pre-catalysts for this oxidative process. We found that in the presence of m-CPBA, the iodoalkanes undergo an oxidative breakdown to inorganic catalytic species (likely IO-- or IO2--). Overoxidation of the in situ formed inorganic species resulted in catalyst deactivation via the formation of a hitherto unreported phase of the iodic acid (HIO3), whose structure has been solved ab initio from the powder x-ray diffraction data. As a second topic, metal nanoparticles are very useful in catalysis due to the particular properties imparted by their size and morphology. A stabilizing agent (S) is usually required to prevent the agglomeration of the NPs, as well as to control the reactivity at the surface. In this thesis, a new PEG-tagged nitrogen-rich stabilizer has been designed and synthesized to prepare water-soluble Au and Rh NPs. We found that by varying the molar ratio S/Rh, we can achieve size and morphology controllable Rh NPs from small atom clusters to nanoflowers. A similar phenomenon was also found for the gold NPs, with morphologies varying from small spheres to nanotadpoles, the sizes of particles depending on the amount of stabilizer. The nanomaterials have been fully characterized. The flower-like Rh NPs proved to be very effective to catalyze the stereoselective hydrosilylation of internal alkynes and they could be easily recycled. The Au NPs were efficient and recyclable catalysts for the selective reduction of various nitroarenes to the corresponding anilines in water at room temperature.

The issues of conflicts between water, energy and food (often referred to as WEFnexus) has become a problem in countries where the energy system is rapidly expanding; one of those countries is Ethiopia. Ethiopia has a large potential of hydropower, which is what most of the electricity production currently comes from. However, this has proven to cause problems on other practices around or close to the power plants. An example is the Omo River basin where the development of the Gibe hydropower cascading scheme, with currently the three power plants Gibe I, I and III operating, have brought up the discussion of the downstream impact. For instance, indigenous people living in the lower parts of Omo river, practice flood recession agriculture, meaning they are depending on the seasonal floods. Further, Omo river has its outflow into Lake Turkana, Kenya, and the lake is highly dependent on the flow regime of the Omo river. Studies on the Omo river have been many, an example is the ones using Topkapi-ETH, a physically based rain-fall runoff model, that models the hydrological aspects of the river and considers, among others, water abstraction for irrigation and diversions to reservoirs for hydropower. However, the hydropower modelled worked on the basis of an averaged power demand; not necessarily reflect the actual demand. Hence, OSeMOSYS, the long-term energy optimization tool, was proposed to complement this study by modelling the energy system in Ethiopia. This current thesis had the aim to do so with the attempt to explore the possibility of a coupling between the models Topkapi-ETH and OSeMOSYS. The aim was to feed OSeMOSYS with varying water availability from Topkapi-ETH; in return, OSeMOSYS would feed Topkapi-ETH with a more realistic required energy production demand. An OSeMOSYS model was set up for Ethiopia, with national data extracted from the study The Electricity Model Base for Africa (TEMBA), disaggregating the hydropower to be able to model each of the hydropower plants in the Gibe cascading scheme individually. To couple the two models, two approaches were developed: Storage module and Reservoir module. The Storage module used the storage feature within OSeMOSYS and used the varying volume in the reservoir from Topkapi-ETH and converted it into an energy potential, as input to OSeMOSYS. The Reservoir module, on the other hand, used the external inflow (sum of all flows except upstream release), obtained from Topkapi-ETH, to the reservoir. An experimental set-up was performed to test how the OSeMOSYS model, with the two modules, would react to the input and which inputs were the driving forces affecting the electricity production. The results showed that OSeMOSYS can respond to the varying water availability received from Topkapi-ETH with the electricity production from the Gibe cascading scheme showed results reflecting this. However, there was a mismatch in the hydrological response in which OSeMOSYS did not seem to fully reflect the volume in the reservoir. For certain cases, the volume would be zero, indicating it would not store any water but instead use all incoming water directly for energy production. Hence, with respect to the results presented in this study, one can conclude that OSeMOSYS is prone to respond to changes in water availability. However, due to the incompatibility in the hydrological perspective in regard to the volume, the coupling is not complete. Before such a complete coupling can be achieved one needs to understand why OSeMOSYS does not reflect the hydrological characteristics. If this can be solved, then a feedback of the required energy production in the Gibe hydropower plants ought to be sent back to Topkapi-ETH.
Konflikten mellan vatten, energi och mat (ofta benämnt WEF-nexus) har blivit ett problem i länder där energisystemet snabbt utvecklas; ett av dessa länder är Etiopien. Etiopien har stor potential i vattenkraft, från vilket den största delen av elektriciteten kommer ifrån idag. Däremot har detta visat skapa problem kring andra verksamheter runtomkring eller i närheten av kraftverken. Ett exempel är Omo RIVER BASIN, beläget i sydvästra Etiopien. Exploateringen av Gibe vattenkraftverk i en kaskad schema, idag med de tre kraftverket Gibe I, IO och III i bruk, har skapat diskussion kring påverkan nedströms. Till exempel så bot Urbefolkningen i den nedre delen av Omo floden, där de utövar så kallad flood recession jordbruk, vilket innebär att de är beroende av säsonger av översvämningar för att bevattna marken. Vidare, Omo floden har sitt utflöde in i Lake Turkana, Kenya, och skön är starkt beroende av flödesregimen i Omo floden. Studier kring Omo floden har varit manga, ett exempel är de som har använt sig av Topkapi-ETH, en fysikaliskt baserad nederbörd yt-avrinnings modell, som modellerat de hydrologiska aspekterna I floden och tar hänsyn till, bland annat, extrahering av vatten i bevattningssyfte och diversion till vattenkraftsdam. Dock modellerade vattenkraftverken med utgångspunkt från ett uppskattat energibehov; nödvändigtvis inte det faktiska behovet. Således föreslogs att OSeMOSYS, en LONGTERM energi optimerings modell, skulle komplimentera denna studie genom att modellera energisystemet i Etiopien. Den här uppsatsen hade som avsikt att testa de föregående med en ansats att undersöka möjligheten att sammankoppla de två modellerna Topkapi-ETH and OSeMOSYS. Målet var att förse OSeMOSYS med en varierad vatten tillgänglighet från Topkapi-ETH; i retur skulle OSeMOSYS förse Topkapi-ETH med ett mer realistiskt energiproduktions behov. En modell i OSeMOSYS skapades för Etiopien, med nationella data extraherad från studien The Electricity Model Base for Africa (TEMBA), där vattenkraftverk disaggregerades för att kunna modellera varje kraftverk I Gibe kaskad schema enskilt. För att sammankoppla de två modeller skapades två tillvägagångssätt: Lagrings modul och Reservoar modul. Magasin modulen använde en lagrings funktion i OSeMOSYS med en funktion av den varierande volym i en reservoar från Topkapi-ETH som omvandlades till en potentiell energi. Reservoar modulen däremot använde externt inflöde (summan av alla flöden förutom upströms utflöde), taget från Topkapi-ETH till reservoaren. Ett försök sattes upp för att testa hur OSeMOSYS modellen, med de två modulerna, skulle reagera till indata och vilken indata som är drivande och påverkar produktionen av elektricitet. Resultaten visade att OSeMOSYS kan besvara ett varierade vatten tillgänglighet kommen från Topkapi-ETH där produktionen av elektricitet från Gibe kaskad schema återspeglade detta. Däremot fanns en missanpassning i den hydrologiska responsen där OSeMOSYS inte fullt ut avspeglade volymen i reservoaren. I vissa fall var volymen noll, vilket tyder på att inget vatten kan lagras utan allt inkommande vatten går direkt till turbiner för produktion av energi. Således, med avseende på resultaten presenterade i den här studien, kan en dra slutsatsen att OSeMOSYS kan svara på variationer i vatten tillgängligheten. Däremot, på grund av missanpassning i hydrologiska perspektivet med avseende på volmen, så är inte sammankopplingen mellan modellerna fullständig. Före en sådan fullständig sammankoppling kan uppnås måste en förstår varför OSeMOSYS inte återspeglar denna hydrologiska karaktär. Om detta kan förstås, så kan en feedback av den fordrade energiproduktionen i Gibe vattenkraftverken återsändas tillbaka till Topkapi-ETH.

Soil and freshwater are two absolutely essential resources for ecosystems and humanity. Agriculture depends very much on these resources, and so, without their correct management, farmland practices can trigger many adverse impacts on the environment and jeopardise the availability of soil and water for future agricultural activities. Agricultural lands represent only 12% of the world’s land area. However, roughly 70% of water withdrawals from nature are for irrigated agriculture and 30-40% of the agricultural land is affected by soil degradation. Desertification, irreversible soil degradation, is one of the main problems for sustainability in drylands, areas that cover 40% of the earth’s surface. For these reasons, the environmental impacts of the use of water and land by agricultural activities should be measured. Life cycle assessment (LCA) is a method to construct the environmental profile of production systems. It was initially developed for industrial production, but a considerable amount of research has been undertaken in recent years to adapt LCA to agricultural systems as well. Conventional LCA methodology does not determine the environmental impacts of water and land use, which is a very significant shortcoming when evaluating the environmental performance of agricultural systems. Furthermore, contrary to other global environmental impact categories such as global warming, the environmental impacts of water and land use vary in every location of the globe, depending on the spatio-temporal conditions of the location, requiring therefore an extension of current LCA methodology. This thesis focuses on the development of the LCA methodology to incorporate the environmental impacts arising from the use of water and land. The spatio-temporal variability of these resources is taken into account in the proposed methods using the complementary tool of geographic information systems (GIS). For water use, two screening frameworks are built to capture the impacts of soil-water consumption by plants, when, until now, efforts have been directed towards evaluating the environmental impacts of irrigation water consumption. For land use, a multi-indicator approach for a new impact category, desertification, until now never modelled in the LCA context, is provided, as well as a methodology for including soil erosion impacts, in which the soil loss has been related to the loss of organic carbon, as a measure of the soil quality, and finally, to the loss of biomass productivity of ecosystems. The methods developed deal with the life cycle inventory (LCI) and the life cycle impact assessment (LCIA) phases. In addition, to verify the applicability of the developed location-dependent methods and characterisation factors, these are applied to agricultural crop rotations with energy crops growing in Spain, with the aim of quantifying the side effects of producing bioenergy on the disputed water and land resources in the country. The outcomes indicate that there is no best solution of a single crop rotation grown in a specific location capable of minimising water and land use environmental impacts simultaneously. This is because, firstly, rainfed crop rotations exhibit higher land use related impacts but, in contrast, they are not irrigated. And secondly, locations with more surface, ground and soil water reserves are subjected to more intensive and erosive rainfalls, thus, to higher land use damages. Among other important follow-up lines of research, future work should focus on the study of suitable functional units for agricultural LCA, calculate the uncertainties of the developed methods as well as try to identify a feasible and relevant geographical scale at which to address the spatial differentiation of the characterisation factors for water and land use impacts, and in general, for any location-dependent impact category.
Suelo y agua dulce son dos recursos imprescindibles para los ecosistemas y la humanidad. La agricultura depende de la disponibilidad de estos recursos, que por tanto, debe gestionar correctamente. En caso contrario, las prácticas agrícolas pueden provocar impactos adversos en el medio ambiente y poner en peligro la disponibilidad de suelo y agua para futuras actividades agrícolas. Los suelos agrícolas representan sólo el 12% de la superficie terrestre mundial. Sin embargo, aproximadamente el 70% de las extracciones de agua de la naturaleza se utilizan en la agricultura de irrigación y el 30-40% de los suelos destinados a la agricultura están degradados. La desertificación, entendida como la degradación irreversible del suelo, es uno de los mayores problemas para la sostenibilidad de las tierras áridas, áreas que cubren el 40% de la superficie terrestre. Por estos motivos, deben evaluarse los impactos ambientales debidos al uso del suelo y del agua en la agricultura. El análisis de ciclo de vida (ACV) es un método para evaluar el perfil ambiental de sistemas productivos. El ACV se desarrolló inicialmente para estudiar la producción industrial, pero en los últimos años la investigación se ha dirigido a la adaptación del método para poder aplicarlo también en los sistemas agrícolas. La metodología convencional de ACV no determina los impactos ambientales debidos al uso del suelo y del agua, siendo ésta una importante deficiencia para evaluar el perfil ambiental de los sistemas agrícolas. Además, al contrario de otras categorías de impacto ambiental global, como el calentamiento global, los impactos ambientales derivados del uso del suelo y del agua son distintos en cada lugar del planeta, en función de las condiciones espacio-temporales del sitio. Por tanto, es necesario extender la metodología actual de ACV. Esta tesis se centra en el desarrollo de la metodología de ACV para incorporar los impactos ambientales resultantes del uso del suelo y del agua. La variabilidad espacio-temporal de estos recursos se tiene en cuenta en los métodos propuestos utilizando la herramienta complementaria de los sistemas de información geográfica (SIG). Para el uso del agua, se presentan dos métodos de aproximación para medir los impactos debidos al consumo de agua de las reservas del suelo, cuando, hasta la fecha, los estudios han intentado evaluar los impactos ambientales debidos al consumo de agua para la irrigación. Para el uso del suelo, se propone una aproximación multi-indicador para modelar el impacto de la desertificación, una categoría nunca antes incluida en ACV, así como una metodología para incluir los impactos de la erosión del suelo, donde la pérdida de suelo se relaciona con la pérdida de carbono orgánico, como medida de la calidad del suelo, y finalmente, con la disminución de producción de biomasa de los ecosistemas. Los métodos desarrollados comprenden las fases de inventario de ciclo de vida (ICV) y de evaluación de impacto de ciclo de vida (EICV). Además, para comprobar la aplicabilidad de los métodos regionalizados de ACV y de los factores de caracterización desarrollados, estos se aplican en rotaciones de cultivos con cultivos energéticos en España, con el objetivo de cuantificar los efectos colaterales de producir bioenergía sobre los recursos suelo y agua, muy disputados en el país. Los resultados revelan que no hay una solución idónea, con una rotación de cultivos sembrados en una zona específica del país, que sea capaz de reducir, simultáneamente, los impactos ambientales debidos al uso de suelo y agua. Esto se debe, en primer lugar, a que los cultivos de secano muestran mayores impactos relacionados con el uso del suelo, pero, al contrario, no utilizan agua de irrigación. Y en segundo lugar, a que las zonas con más reservas de agua en superficie, acuíferos y suelos están también sometidas a lluvias más intensas y erosivas, y en consecuencia, a un mayor deterioro del suelo. Entre otras importantes líneas de investigación a seguir, próximos trabajos deben centrarse en el estudio de unidades funcionales adecuadas para el ACV de sistemas agrícolas, el cálculo de las incertidumbres de los métodos desarrollados en la tesis, así como en la identificación de una escala geográfica significativa y de aplicación factible que aborde la diferenciación espacial de los factores de caracterización para los impactos del uso del suelo y del agua, y, en general, para cualquier categoría de impacto ambiental regional.

Les nanotechnologies ont ouvert de nouvelles perspectives pour l’administration ciblée des médicaments. Les approches actuelles en nanomédecine sont basées sur l’encapsulation d’un principe actif dans un nano-vecteur. Nous proposons dans ce travail l’utilisation de nanoparticules non plus pour adresser un médicament encapsulé vers sa cible, mais pour manipuler une protéine d’intérêt en milieu biologique, ce qui constitue une nouvelle stratégie thérapeutique. Avec cet objectif, nous avons identifié une formulation de nanoparticules de palladium, stable, non toxique et dotée d’un pouvoir catalytique remarquable de la réaction de Suzuki-Miyaura. Ce nano-catalyseur permet, en utilisant un dérivé du bore approprié, de greffer des résidus aromatiques sur des acides aminés halogénés dans un tampon phosphate à température et pH physiologiques. En parallèle, la formulation sous forme de nanoparticules de calixarenes fonctionnalisés par des complexes carbéniques du palladium a été également étudiée. Ce nano-réacteur permet d’effectuer dans l’eau et à température ambiante une réaction d’arylation d’amino acides halogénés de manière très efficace. Nous montrons qu’il est possible grâce à ces nanoparticules de modifier sélectivement par une liaison covalente, la thyroglobuline, une protéine naturelle halogénée, impliquée dans la maladie de Basedow et dans certains cancers de la thyroïde. L’absence de modèle cellulaire exprimant la protéine nous a conduit à tester la réaction dans un homogénat d’organe provenant de l’exérèse chirurgicale de la thyroïde chez un patient de la maladie de Basedow. Le couplage de la thyroglobuline par réaction de Suzuki-Miyaura a pu être détecté par analyse protéomique grâce au marquage par un cycle aromatique simple, et par western blot à l’aide d’une sonde biotine autorisant une détection par immuno-essai. En conclusion, la thèse apporte la démonstration de la formation sélective d’une liaison C-C sur une protéine par des nanoparticules de palladium dans un milieu biologique complexe et en conditions physiologiques. Ces résultats pourraient ouvrir la voie à de nouvelles options thérapeutiques permettant de controler le taux de thyroglobuline dans le cas d’une dérégulation hormonale
Nanotechnology has opened up new perspectives for targeted drug delivery in the treatment of severe diseases. Current approaches in nanomedicine are based on the encapsulation of an active drug in a nanocarrier. In the present study, we have used nanoparticles not to address an encapsulated drug to a target tissue, but for manipulating a protein of interest in a complex biological medium. With this aim, we have identified a stable, non-toxic palladium nanoparticle formulation, embedding a remarkable catalytic activity on the Suzuki-Miyaura reaction. This nano-catalyst allows by using an appropriate boron derivative to couple aromatic residues onto halogenated amino acids in a phosphate buffer at physiological pH. By the same way, the formulation as nanoparticles of calixarene derivatives functionalized with palladium carbene complexes was studied. This new nano-reactor allowed similarly the arylation reaction of halogenated amino acids in water and at ambient temperature in a very efficient manner.We showed that it is possible, thanks to these nanoparticles, to modify selectively by a covalent bond the thyroglobulin, a halogenated natural protein, implicated in Graves' disease and in certain thyroid cancers. The absence of a protein-expressing cellular model led us to test the reaction in an organ homogenate from surgical thyroid excision from a Graves' disease patient. The coupling of thyroglobulin by Suzuki-Miyaura reaction was detected by proteomic analysis by labeling with a simple aromatic ring and by western blotting using a biotin probe allowing detection by immunoassay. In conclusion, the study undertaken in the thesis has shown the selective formation of a CC bond onto a natural protein in a complex biological medium and under physiological conditions, by using palladium nanoparticles. This result paves the way for new therapeutic perspectives to control the level of thyroglobulin in the case of hormonal dysregulation

Ce travail porte sur la mise en œuvre de simulations sur des pales de machines tournantes. Une première partie de la thèse porte sur l’amélioration des performances du couplage fluide-structure. Des nouveaux algorithmes sont présentés. Une nouvelle méthode de déformation de maillage est évaluée. Les développements sont validés à partir de plusieurs cas tests. La deuxième partie porte sur l’application des avancées à des machines tournantes. Une première validation est faite sur une hydrolienne. La vibration d’une pale au passage du mat est étudiée. Enfin, des résultats sur une hydrolienne industrielle sont exposés
A methodology to simulate blades of turbines is developed. A first part is dedicated to improving the performance of the fluid-structure coupling. New algorithms are presented. A new mesh morphing solution is shown. Developments are validated on many test cases. A second part is dedicated to applying the developments on turbines. A first validation is made on a water turbine. The vibration of a blade interacting with a mast is studied. Finally, some results of an industrial water turbine are shown

Thesis (Ph. D.)--Chemistry and Biochemistry, Georgia Institute of Technology, 2008.
Christoph J. Fahrni, Committee Member ; Mostapha A. El-Sayed, Committee Member ; Christopher W. Jones, Committee Member ; Marcus Weck, Committee Chair ; E. Kent Barefield, Committee Member.

A number of novel isoindoline nitroxides have been synthesised using a variety of synthetic techniques. Several carbon-carbon bond forming methodologies, including the first examples of Heck and Sonogashira coupling applied to the isoindoline nitroxide class, were utilised to give novel robust aromatic frameworks. Palladium-catalysed Heck coupling of brominated nitroxides and ester-substituted olefins generates novel nitroxides possessing extended conjugation. Hydrolysis of the nitroxide esters gave the corresponding carboxylic acids, which showed enhanced water solubility. Sonogashira coupling of an iodo-isoindoline nitroxide gave several novel alkynesubstituted nitroxides in high yield. Subsequent coupling of a deprotected ethynyl nitroxide with aromatic iodides gave acetylene-linked nitroxides and an acetylene linked nitroxide dimer. A butadiyne linked dinitroxide was successfully synthesised via Eglinton oxidative coupling of two ethynyl nitroxides. The synthesis of a novel water-soluble dicarboxy nitroxide was achieved by base hydrolysis of a dinitrile. Functional group interconversion furnished anhydride and imide substituted nitroxides from the diacid. Subjecting the imide to the Hofmann rearrangement gave an unexpected brominated amino-carboxy nitroxide. The dicarboxy nitroxide and the brominated amino-carboxy nitroxide were both shown to have a protective effect on Ataxia-Telangiectasia cells, indicating a possible role as antioxidants in the treatment of this disease. A fluorescein nitroxide was successfully synthesised through the condensation of the anhydride substituted nitroxide and resorcinol. After limited success using a variety of other techniques, Buchwald-Hartwig amination was able to furnish a rhodamine nitroxide, via a triflate-fluorescein nitroxide. The extended aromatic nitroxides possess suppressed fluorescence and we have described these systems as profluorescent. The profluorescent nitroxides were found to have significantly lower quantum yields than the non-radical analogues and displayed a substantial increase in fluorescence intensity upon radical trapping, making them useful probes for free radical reactions.

La photocatalyse est un procédé d’oxydation avancée et son utilisation est répandue dans le traitement de l’eau. Cette thèse traite de la dépollution d’eau au sein d’un réacteur original mettant en oeuvre un textile lumineux photocatalytique. Le textile est composé de fibres optiques parallèles situées sur une face d’un tissu fibreux. L’unité d’un tel système est assurée par des points de liage répartis périodiquement fixant les fibres optiques au tissu. Un traitement de microtexturation des fibres optiques permet la création d’une multitude de trous sur leur surface latérale. Une émission de lumière macroscopiquement homogène est provoquée lors de la connexion des fibres optiques à une lampe UV. Un dépôt de catalyseur, tel que le dioxyde de titane, sur l’intégralité du textile, conjuguée au rayonnement UV induit une activité photocatalytique. Cette thèse consiste à l’étude des phénomènes agissant dans un dispositif intégrant le textile lumineux photocatalytique. Dans ce réacteur plan modèle, le textile est confiné entre deux plaques et un écoulement unidirectionnel parallèle aux fibres optiques est mis en oeuvre. La dépollution d’un fluide par photocatalyse résulte du couplage de plusieurs mécanismes : écoulement, transport et réaction. Des modèles numériques sont ainsi développéssur un volume élémentaire représentatif du textile (appelé RVE) pour simuler la dépollution d’une eau comportant une molécule test, à l’échelle microscopique. Cette géométrie est choisie en tenant compte des caractéristiques structurelles du textile photocatalytique. La première étape est l’analyse de l’hydrodynamique au sein du textile, qui couple des écoulements fluide et en milieu poreux. Une étude expérimentale préliminaire a permis l’acquisition de données nécessaires à une représentation réaliste de l’écoulement en milieu poreux. Dans un second temps, le transport est caractérisé par une étude de la distribution des temps de séjour (DTS) au sein du réacteur. Des simulations successives utilisant des conditions aux limites pseudo-périodiques sont réalisées pour calculer numériquement la DTS. Elles sont validées par des mesures expérimentales de traçage de colorant. Enfin, la dégradation d’une molécule test est analysée expérimentalement et numériquement. L’étude numérique présente des approches macroscopique et microscopique. L’étude à l’échelle macroscopique permet de quantifier globalement les performances du réacteur et de fournir des valeurs de constantes cinétiques nécessaires aux simulations àl’échelle microscopique. Une analyse fine et précise de la dépollution est ainsi réalisée au sein du RVE. Elle montre les atouts et limitations du réacteur modèle en termes d’efficacité de dépollution et d’homogénéité de fonctionnement. Des propositions d’améliorations sont finalement émises, notamment une configuration de réacteur comportant un empilement de textiles photocatalytiques
The photocatalysis is known as an advanced oxidation process and its use is common for the water treatment. This thesis deals with the water depollution within an original reactor integrating the UV-light photocatalytic textile. The textile is composed of parallel optical fibres located on a side of a fibrous fabric. The unity of the system is ensured by bonding points periodically distributed fixing the optical fibres to the fabric. A microtexturization treatment is applied to the optical fibres and a multitude of punctual light sources are thus created on their lateral surface. A light emission macroscopically homogeneous is provided by the connection of optical fibres to an UV lamp. The coating of catalyst, such as titanium dioxide, associated with UV irradiation generates photocatalytic activity. This thesis consists in studying phenomena which occurs within a setup containing the UV-light photocatalytic textile. In this model plane reactor, the textile is confined between two plates and a unidirectional flow parallel to optical fibres is applied. The fluid depollution results of the coupling between several mechanisms : fluid flow, transport and reaction. Numerical models are thus developed on a representative volume element of the textile (called RVE) to simulate at the microscopic scale the depollution of water containing a test molecule. This geometry is designed by taking account the structural characteristics of the photocatalytic textile. The first stage is the analysis of the hydrodynamic within the textile that combines free flow regions and porous medium flows. A preliminary experimental study allows the acquisition of data necessary to a realistic representation of the porous medium flow. Secondly, the transport is characterized by a study of the residence time distribution (RTD) within the reactor. Successive simulations using pseudo-periodic boundary conditions are performed to numerically calculate the RTD. They are validated by experimental measurements using dye tracing. Finally, the degradation of a test molecule is analysed experimentally and numerically. The numerical study presents both approaches macroscopic and microscopic. The study at the macroscopic scale allows to globally quantify the reactor performances. On the other hand, kinetic constants necessary to simulations at the microscopic scale are determined by fitting of the macroscopic model with experimental measurements. An accurate analysis is thus realized within the RVE. It points the advantages and limitations of the model reactor in terms of depollution efficiency and functioning homogeneity. Suggestions of structural improvement are proposed and especially a reactor integrating a stack of photocatalytic textiles

Les sites chimiques, pétrochimiques et pétroliers génèrent des effluents chargés en polluants soumis à une réglementation de plus en plus stricte. Le travail de thèse se focalise sur le traitement des effluents industriels et plus spécifiquement sur l'amortissement des pics de pollution via un procédé d'adsorption/désorption afin de minimiser les impacts négatifs sur l'épuration biologique. Pour cela, deux études complémentaires ont été menées en parallèle. La première étude concerne l'adsorption et la désorption de polluants en phase aqueuse avec notamment la sélection d’un adsorbant puis la détermination de ses capacités d'adsorption vis-à-vis de deux molécules modèles. Plusieurs cycles d'adsorption et de désorption ainsi que des pics de pollution ont été réalisés afin de (i) démontrer la faisabilité du procédé, (ii) d'identifier les phénomènes mis en jeu et les paramètres déterminants dans la capacité d'amortissement d'une colonne d'adsorbant et (iii) étudier les phénomènes de compétition entre molécules. Les données expérimentales ont pu être modélisées avec succès à l'aide d’un couplage du modèle Linear Driving Force (LDF) et de l'isotherme de Freundlich. D'autre part, l'impact d'une variation de charge sur les performances épuratoires du traitement biologique seul a été examiné et comparé aux effets observés lors d'un pic de pollution sur un procédé couplant une colonne d'adsorbant (en amont) et le traitement biologique. Un intérêt a également été porté aux foisonnements de bactéries filamenteuses, survenus à plusieurs reprises : une identification des filaments a été réalisée et un traitement de lutte efficace a été mis en place. Les résultats ont démontré qu'une colonne d'adsorbant placée en amont du bassin de biodégradation permet d'améliorer la qualité de l'effluent traité et ainsi de respecter les normes de rejet fixées par la législation.

[ES] En la actualidad, una gran cantidad de infraestructuras están compuestas de forma parcial o total de materiales cementicios, siendo el hormigón uno de los materiales cementicios más antiguos y utilizados en la construcción debido a su bajo coste, durabilidad y características mecánicas y estructurales. Pese a sus características, estos materiales están expuestos a diversas condiciones adversas del entorno y sufren procesos de deterioro que afectan a su integridad y seguridad. El reconocimiento de la integridad y seguridad en las estructuras cementicias ha implicado una extensa investigación y el desarrollo de diversas pruebas para verificar su calidad y estado. Mediante la destrucción de una muestra extraída de la estructura, en el caso de los ensayos destructivos (ED), o mediante la inspección de la estructura sin necesidad de dañarla o alterar sus propiedades, en el caso de los ensayos no destructivos (END). Existen multitud de técnicas END que tratan de caracterizar estas estructuras sin dañarlas, siendo la inspección mediante ultrasonidos una de las más utilizadas en materiales cementicios. Tradicionalmente estas técnicas ultrasónicas se basan en el estudio de las ondas longitudinales (P) y transversales (S), que permiten caracterizar una estructura mediante la realización de múltiples medidas. Sin embargo, existe otro tipo de ondas, formadas por la superposición de los desplazamientos de las partículas de las ondas P y S denominadas ondas guiadas, las cuales permiten inspeccionar una estructura de forma global a partir de una única medida, además de ser capaces de propagarse a grandes distancias manteniendo una buena relación señal-a-ruido en comparación a las ondas P y S. Dentro de las ondas guiadas más utilizadas para inspeccionar materiales cementicios, se encuentran las ondas de Rayleigh y las ondas de Lamb. Las ondas de Rayleigh se propagan en estructuras de gran espesor, mientras que las ondas de Lamb se propagan en placas. Las ondas de Lamb presentan una naturaleza dispersiva y multimodal. Su naturaleza dispersiva implica que las velocidades de fase y grupo de estas ondas depende de la frecuencia, mientras que la naturaleza multimodal implica que existen cada vez más modos de propagación conforme aumenta la frecuencia de excitación. Se pueden excitar y detectar selectivamente los distintos modos de Lamb mediante la incidencia oblicua, es decir, variando la inclinación del transmisor y el receptor. Para ello, existen distintas técnicas de acoplamiento que permiten la incidencia oblicua, como el acoplamiento por cuñas sólidas, el acoplamiento por agua y el acoplamiento por aire. La presente tesis se ha centrado en el estudio de nuevas técnicas de END basadas en ondas guiadas para caracterizar diferentes tipos de daño en los materiales cementicios. Para ello, se han llevado a cabo un número considerable de medidas experimentales basadas en distintas técnicas de acoplamiento para la generación y captación de ondas guiadas. Inicialmente se han analizado materiales homogéneos como los metales, para, posteriormente, utilizar el conocimiento adquirido en dichos materiales y estudiar materiales más heterogéneos como los cementicios. Se han evaluado diferentes tipos de técnicas de acoplamiento junto con diferentes tipos de transductores. Los materiales cementicios se han inspeccionado mediante ondas guiadas ultrasónicas con dos tipos de daño: la carbonatación, estudiando el efecto con probetas de dos capas de mortero, y el envejecimiento de fibras en placas de cemento reforzado con fibra de vidrio (GRC). Se ha demostrado que las ondas guiadas son sensibles a estos daños, obteniendo resultados esperanzadores. Concretamente, las ondas de Rayleigh se han utilizado en el daño por carbonatación debido a su sensibilidad a capas superficiales de degradación, mientras que en el envejecimiento de fibras se han utilizado las ondas de Lamb, por su sensibilidad a defectos a lo largo
[CA] En l'actualitat, una gran quantitat d'infraestructures estan formades totalment o parcialment de materials cementants. El formigó és un dels materials cementants més antics i utilitzats en la construcció degut al seu preu, la seua durabilitat i les seues característiques mecàniques i estructurals. Malgrat la seua durabilitat i característiques, aquests materials estan exposats a diverses condicions adverses de l'entorn i pateixen processos de deterioració que afecten la seua integritat i seguretat. El reconeixement de la integritat i seguretat en les estructures cementants ha implicat una extensa investigació i el desenvolupament de diverses proves per a verificar la seua qualitat i estat. Mitjançant la destrucció d'una mostra de l'estructura en el cas dels assajos destructius, o mitjançant la inspecció de l'estructura sense danyar-la o alterar les seues propietats en el cas dels assajos no destructius. Existeixen multitud de tècniques d'inspecció no destructiva que tracten de caracteritzar aquestes estructures sense danyar-les. La inspecció mitjançant ultrasons és un dels assajos no destructius més utilitzats en materials cementants. Tradicionalment, aquestes tècniques ultrasòniques estan basades en l'estudi de les ones longitudinals (P) i transversals (S), que permeten caracteritzar una estructura mitjançant la realització de múltiples mesures en l'estructura. No obstant, existeixen altres tipus d'ones, formades per la superposició dels desplaçaments de les partícules de les ones P i S, denominades ones guiades, les quals permeten inspeccionar una estructura de manera global a partir d'una única mesura, a més de poder propagar-se a grans distàncies mantenint una bona relació senyal-soroll en comparació a les ones P i S. Dins de les ones guiades més utilitzades per a inspeccionar materials cementants, es troben les ones de Rayleigh i les ones de Lamb. Les ones de Rayleigh es propaguen en estructures de gran grossària, mentre que les ones de Lamb es propaguen en plaques. Les ones de Lamb presenten una naturalesa dispersiva i multimodal. La seua naturalesa dispersiva implica que les velocitats de fase i grup d'aquestes ones depenen de la freqüència, mentre que la naturalesa multimodal implica que apareguen més modes de propagació a l'augmentar la freqüència d'excitació. Es poden excitar i detectar selectivament els diferents modes de Lamb mitjançant la incidència obliqua, és a dir, variant la inclinació del transmissor i el receptor. Existeixen diferents tècniques d'acoblament que permeten la incidència obliqua, com l'acoblament per metacrilat, l'acoblament per aigua i l'acoblament per aire. Aquesta tesi s'ha enfocat en l'estudi de noves tècniques d'assajos no destructius basades en ones guiades (ones de Rayleigh i ones de Lamb) per a caracteritzar diferents tipus de dany en els materials cementants. S'han realitzat un nombre considerable de mesures experimentals basades en diferents tècniques d'acoblament per a la generació i captació d'ones guiades. Inicialment s'han analitzat materials homogenis com els metalls per a, posteriorment, utilitzar el coneixement adquirit en aquests materials i estudiar d'altres més heterogenis com els cementants. Concretament, s'han avaluat diferents tipus de tècniques d'acoblament i diferents tipus de transductors. Els materials cementants s'han inspeccionat mitjançant ones guiades ultrasòniques amb dos tipus de dany o degradació: la carbonatació, estudiant el seu efecte amb provetes de dues capes de morter, i l'envelliment de fibres en plaques de ciment reforçat amb fibra de vidre (GRC). S'ha demostrat que les ones guiades són sensibles a aquests danys, obtenint resultats esperançadors. Concretament, les ones de Rayleigh s'han utilitzat en el dany per carbonatació a causa de la seua sensibilitat a capes superficials de degradació, mentre que en l'envelliment de fibres s'han utilitzat les ones de Lamb, per la seua sensibilitat a defe
[EN] Nowadays, a large number of infrastructures are partially or wholly built with cementitious materials. Concrete is one of the oldest and most popular cementitious materials due to its low cost, durability and remarkable mechanical and structural characteristics. However, if these materials are exposed to different environments and harsh conditions, they suffer damaging processes that affect their integrity and safety. To verify their state and quality, extensive research has been conducted and several tests have been developed, such as destructive testing and non-destructive testing. Destructive testing (DT) requires a sample of the inspected structure while non-destructive testing (NDT) allows the inspection of the structure without altering its properties and without damaging it. There are several NDT techniques that characterize cementitious structures without harming them, such as ultrasonic testing, which is one of the most widely used. This technique is based on the study of longitudinal (P) and shear (S) waves, which enable the characterization of a structure by a point-by-point scan. However, there are another kind of waves, called guided waves, which are composed of the superposition of the P and S wave particle displacements. Unlike P and S waves, guided waves allow a global inspection of a structure from a single transducer position and they are able to propagate over long distances with a good signal-to-noise ratio. Rayleigh and Lamb waves are the most frequently used guided waves in NDT of cementitious materials. Rayleigh waves propagate in thick structures while Lamb waves propagate in plate-like structures. Lamb waves are dispersive (their phase and group velocities depend on frequency) and multimodal (as frequency increases, many propagation modes with different velocities exist in the received signal). Lamb wave modes can be selectively excited and detected by means of oblique incidence, i.e., by varying the inclination of the transmitting and receiving transducers. Different coupling techniques can be used to change the inclination of the transducers, such as the contact technique with angle beam wedge transducers, water coupling and air coupling. This thesis has been focused in the study of new NDT techniques based on guided waves (Rayleigh and Lamb waves) to characterize different types of damage of cementitious materials. For this goal, a significant number of experimental arrangements based on different coupling techniques have been carried out. Firstly, homogeneous materials as metals have been analized, because they are a reference in guided wave testing. After performing different experiments in metals, the acquired knowledge has been used to inspect heterogeneous materials as cementitious ones. Different coupling techniques (variable angle wedges, immersion testing, fixed angle wedges, ...) with different types of transducers (contact transducers, immersion transducers and air-coupled transducers) have been employed. Cementitious materials with two damaging processes have been inspected by means of guided waves: two-layered mortar specimens to study carbonation and glass-fibre reinforced cement (GRC) plates to study fiber ageing. This thesis demonstrates that guided waves are sensitive to these damaging processes and the obtained results are encouraging. Specifically, Rayleigh waves have been used to detect carbonation due to its sensitivity to surface layers, while Lamb waves have been used to detect fiber ageing due to its sensitivity to defects along the thickness of the GRC plates.
La investigación realizadaen esta tesis se ha financiado con las siguientes ayudas y proyectos concedidos por el gobierno español: Ayudas para contratos predoctorales para la formación de doctores 2015 (BES-2015-071958); Nuevas aplicaciones de ensayos no destructivos basados en ondas mecánicas para la evaluación de la degradación en materiales cementantes (BIA2014-55311-C2-2-P); Desarrollo y aplicación de ensayos no destructivos basados en ondas mecánicas para la evaluación y monitorización de reología y autosanación en materiales cementantes (BIA2017-87573-C2)
Vázquez Martínez, S. (2021). Nuevas técnicas de ensayos no destructivos basadas en ondas mecánicas para la valoración del daño en materiales cementicios [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/165531
TESIS

DYN3D is an best estimate advanced code for the three-dimensional simulation of steady-states and transients in light water reactor cores with quadratic and hexagonal fuel assemblies. Burnup and poison-dynamic calculations can be performed. For the investigation of wide range transients, DYN3D is coupled with system codes as ATHLET and RELAP5. The neutron kinetic model is based on the solution of the three-dimensional two-group neutron diffusion equation by nodal expansion methods. The thermal-hydraulics comprises a one- or two-phase coolant flow model on the basis of four differential balance equations for mass, energy and momentum of the two-phase mixture and the mass balance for the vapour phase. Various cross section libraries are linked with DYN3D. Systematic code validation is performed by FZR and independent organizations.

DYN3D is an best estimate advanced code for the three-dimensional simulation of steady-states and transients in light water reactor cores with quadratic and hexagonal fuel assemblies. Burnup and poison-dynamic calculations can be performed. For the investigation of wide range transients, DYN3D is coupled with system codes as ATHLET and RELAP5. The neutron kinetic model is based on the solution of the three-dimensional two-group neutron diffusion equation by nodal expansion methods. The thermal-hydraulics comprises a one- or two-phase coolant flow model on the basis of four differential balance equations for mass, energy and momentum of the two-phase mixture and the mass balance for the vapour phase. Various cross section libraries are linked with DYN3D. Systematic code validation is performed by FZR and independent organizations.

Cette thèse développe et discute différentes approches micro-économiques de modélisation de l’agriculture pour représenter l’effet de changements globaux et de politiques de gestion de l’eau sur l’adaptation de l’agriculture et sur les ressources en eau. Après un chapitre de synthèse et une revue de la littérature, quatre essais sont présentés. Le premier essai décrit la représentation du comportement de dix exploitations agricoles en Alsace et en Bade (Allemagne) à partir de modèles de programmation linéaire qui intègrent la prise en compte du risque. Après extrapolation, les résultats de simulation sont couplés à une chaîne de modèle plante-sol et de transfert hydrogéologique afin d’estimer la concentration future en nitrate dans l’aquifère du Rhin supérieur. Les simulations des trois scénarios de changements - tendanciel, libéral et interventionniste - suggèrent que les concentrations en nitrates baissent dans les trois cas par rapport à la référence. Le second essai explore l’effet de l’incertitude de changements globaux sur les ressources en eau par des simulations Monte Carlo pour le modèle alsacien (premier essai) et un modèle de demande en eau agricole (Sud-Ouest). Plusieurs niveaux de dépendance entre les paramètres incertains sont caractérisés. L’analyse des résultats montre que les objectifs environnementaux peuvent être déterminés avec suffisamment de précision malgré l’incertitude forte. Le troisième essai développe un modèle agricole régional de programmation mathématique positive avec élasticité de substitution constante entre l’eau et la terre afin d’explorer comment l’agriculture, partiellement irriguée, de Beauce s’adapte à une baisse de la disponibilité en eau. La réponse du rendement à l’eau est calibrée à partir d’information agronomique. Les adaptations à la baisse de disponibilité en eau sont distinguées selon qu’elles correspondent à des baisses de dose d’eau d’irrigation ou de changement de culture. Environ 20% de la réduction est due à la baisse des doses d’eau (marge intensive). Le dernier essai présente un modèle hydro-économique “holistic” de l’agriculture et de l’aquifère de Beauce afin d’évaluer plusieurs politiques de gestion quantitatives de l’eau ainsi que d’évaluer le cas où l’accès à la ressource n’est plus régulé. Des simulations dynamiques sont réalisées à l’horizon 2040 en tenant compte de l’incertitude liée au changement climatique. La politique actuelle de quotas annualisés semble être plus coût-efficace que les autrespolitiques testées (taxes, transferts etc.)
This thesis develops and discusses agricultural-supply modeling approaches for representing the adaptation of farming to global changes and water policies: their effects on agricultural economics and water resources comprise critical information for decision makers. After a summary and a review chapter, four essays are presented. The first essay describes a representation of the behavior of ten typical farms using a risk linear programming model connected to a plant-soil-hydrodynamic model chain, to assess the future level of nitrate contamination in the upper Rhine valley aquifer. The baseline, liberal, and interventionist scenarios for 2015 all result in lower nitrate concentrations. The second essay explores the effects of the economic uncertainty of global changes by means of a Monte Carlo approach distinguishing various levels of dependence on uncertain parameters. Analyses for a nitrate-oriented and a water-use model (in Alsace and southwestern France) show that the environmental objectives can be targeted withsufficient confidence. The third essay develops a flexible specification for positive mathematical programming - constant elasticity of substitution with decreasing returns - to explore how irrigated farming adapts to increased water scarcity in Beauce, France. The possibility of adjusting the application of water per hectare accounts for about 20% of the response. The last essay presents the development of a holistic hydro-economic model of Beauce’s agriculture and aquifer under climate-change uncertainty, so as to evaluate various water policies, as well as the open-access case, up to the year 2040. The results show that the baseline policy is more cost-effective than the other instruments tested (tax, transfer,etc.)

Este trabalho está focado no desenvolvimento de complexos de rutênio binucleares baseados no ligante ponte 2,6-bis(2-piridil)benzodiimidazol (dpimH2) com potencial aplicação como catalisadores para oxidação da água. O acoplamento eletrônico entre os centros metálicos bem como as propriedades eletrônicas e catalíticas podem ser controlados via reações ácido-base no ligante bis-bidentado. Dessa forma, neste trabalho descrevemos o preparo e a caracterização do respectivo composto mononuclear, bem como do complexo binuclear simétrico [{RuCl(phtpy)}2(dpimH2)](Otf) 2 (onde phtpy=4-fenil-2,2\':6\',\'\'-terpiridina), e do análogo assimétrico [{Ru(bpy)2}(dpimH2){Ru(phtpy)Cl}](ClO4)3 (onde bpy=2,2\'-bypiridina), que possui um centro catalítico e um grupo cromóforo na mesma molécula como esperado em um fotocatalisador, em que os dois centros catalíticos estão covalentemente conectados através do ligante ponte funcional. As caracterizações estrutural e eletrônica de ambos os complexos por 1H RMN, ESI-MS e espectroscopia de absorção UV-Vis indicaram a presença de isômeros geométricos com perfis eletrônicos similares. Por outro lado, a análise eletroquímica por voltametria cíclica demonstrou menores potenciais Ru(III/II) quando comparados a complexos polipiridínicos análogos. Este potencial redox pode ainda ser catodicamente deslocado através da remoção de prótons dos grupos imidazóis do ligante ponte, possibilitando, dessa forma, a modulação das propriedades eletrônicas e catalíticas destes complexos de rutênio através de reações de protonação/desprotonação dos grupos -NH. Além disso, neste trabalho é investigada a inesperada formação do complexo [Ru(phtpy)2] nas reações do complexo [RuCl3(phtpy)] puro com ligantes bidentados, utilizando-se espectroscopia UV-Vis e de 1H RMN.
This work is focused on the development of dinuclear ruthenium complexes with potential application as catalysts for oxidation of water, that are characterized by a benzobisimidazole 2,6-bis(2-pyridyl)benzodiimidazole (dpimH2) bridging ligand, whose interaction between the metal centers as well as the electronic and catalytic properties can be tuned by acid-base reactions in that moiety. Thus, the preparation and characterization of the respective mononuclear species are described. The dinuclear complex [2(dpimH2)](Otf)2(phtpy=4-phenyl-2,2\':6\',2\'\'-terpiridine), in which two catalytic centers are covalently linked through that bridging ligand, and of the [(dpimH2)](ClO4)3 complex (where bpy=2,2\'-bypiridine) integrating a chromophore and a catalytic center in the same molecule as expected for a photocatalyst. The structural and electronic characterization of both complexes by NMR, ESI-MS and UV-vis spectroscopy indicated the presence of geometric isomers with similar electronic profiles. On the other hand, the electrochemical analysis by cyclic voltammetry displayed redox potential values for the Ru3+/Ru2+ couples lower than the respective polypyridyl complex counterparts. This redox potential can be even more shifted to less positive potentials by removal of protons from the imidazole groups in the bridging ligand, opening the possibility of tuning the electronic and catalytic properties of those ruthenium complexes based on protonation/deprotonation of the -NH groups. Furthermore, in this work is analyzed the unexpected formation of the bisterpyridine [Ru(phpy)2] complex in reactions starting with pure [RuCl3(phtpy)] complex with bidentated ligands, as through UV-Vis spectroscopy and RMN.

In this project we have been working with two different instruments home-made AMA 254 and Hydride Generator. Home-made AMA 254 was coupled to a fluorescence detector. The Hydride Generator was coupled to atomic absorption spectroscopy (AAS), by an optical path. Calibration of mass-flow controller by applying a suitable gas in the inlet and a bubbles calibration unit at the outlet. All date was saved by labview program was used The first configurations, carrier gas was fed into the middle of the catalyzer tube and the gold-trap by a T-shape connector to carry mercury to the detector. Condensation of mercury vapour when the gas-stream collided to the silicon walls, at the T-shape connection leads to failing. Second configuration, two positioned-switching valve was introduced between the oxygen and argon tanks, allowing only one gas to reach MFC depending on the switching position. There are four different parameters memory effects, repeatability, accuracy and sensitivity, have to investigated to know that the machine gives reliable result when running real samples. Memory effects: Memory effect is one reason for deviation of the analysis. It is obvious that some mercury still remains within the tube after running. Memory effect is not significant at high concentration of the analyte, but could be troublesome at lower concentration. Repeatability: Repeatability was tested by running 3 replicates with the same concentration of the analyte. This is important for knowing the precision of the analysis. Accuracy: The Reference material MESS-92 (92ppb) was used to evaluate the accuracy of the analysis . Triplicate was running and the mean value was calculated to 98.3 ppb, the deviation was 6.86%. Sensitivity: By comparing the mercury fluorescence detector and atomic absorption (AAS) it become evident that the fluorescence detector is much more suitable for analysis with AMA 254 as it gave an overloaded signal whereas the atomic absorption only appeared as noise. Minor Field Study in Chemistry – Autumn 2010 Page 4 The comparison between the mercury fluorescence detector and atomic absorption (AAS) was done with 0.05 gram(g) tuna fish samples. Mercury fluorescence detector gave an overloaded signal, whereas the AAS signal appeared as noise. It is evident that the fluorescence detector is much more sensitive than the AAS detector. Hydride generation is one common method for determining mercury in water. Three different channels are used for pumping the solutions and forming hydride, they are Hydrochloric acid, NaBH4and sample (blank, standards). The hydride form of mercury was flushed and collected into the gold trap by nitrogen gas. After that the gold-trap is heated up to release mercury optical cell where the absorption as a peak was measured in the same manner as normal flame AAS without using of flame. In our project we also made up a temperature controller to control the temperature. The real temperature was measured by thermocouple and was designed like a small box.