No description available.

Les sols organiques de la région de Montérégie permettent une culture maraîchère productive. Cependant, leur mise en culture amène la dégradation du sol. Un sol organique dégradé peut montrer un drainage problématique pour deux raisons principales. Premièrement, il est composé de particules de sols très fines qui migrent dans le sol et forment une couche compacte de très faible perméabilité relativement près de la surface, typiquement entre 25 et 40 centimètres de profondeur. Cette couche va limiter de façon importante le rabattement de l’eau de surface. Deuxièmement, lorsqu’il se décompose, le sol s’affaisse sous son propre poids et la couche de dessous, composée principalement d’argile ou de coprogène peu perméable, vient jouer un rôle de plus en plus important dans le ralentissement du drainage. Une solution à ce problème généralisé de drainage pourrait être l’installation des drains en tranchées drainantes remplies avec un matériel de meilleure perméabilité comme un mélange de sol organique et de biomasse broyée. Le premier objectif de ce mémoire est d’évaluer la stabilité de différents mélanges par le changement de la conductivité hydraulique à saturation au cours d’un drainage continu en colonnes de sol. Le second objectif est de modéliser l’effet comparé de la présence d’une tranchée drainante ou d’un drainage conventionnel sur le drainage d’un profil de sol réel ayant une faible profondeur de sol organique. Cinq différents mélanges ont été testés dans des colonnes d’une hauteur de 60 cm (trois mélanges de sol organique avec de la biomasse broyée de saule, de miscanthus ou de pin défibré, une tresse de fibre de coco qui agissait comme un drain vertical partant du drain à 20 cm de la surface et un témoin composé uniquement de sol organique). Les colonnes ont été gardées saturées avec une hauteur d’eau constante durant 36 jours au cours desquels la conductivité hydraulique saturée a été mesurée à plusieurs reprises. La modélisation du drainage s’est faite avec Hydrus. Les paramètres du modèle de Van Genuchten de la courbe de rétention mesurés en plusieurs points ont été déterminés pour les différents mélanges pour tranchée drainante. Les paramètres du modèle ont également été obtenus pour le profil de champ réel à l’aide de données de hauteurs d’eau et de débit au drain. Les résultats montrent que le mélange avec la plus grande stabilité était le pin défibré; il avait la conductivité la plus élevée pour une quantité d’eau passée dans la colonne plus importante. iii Avec la modélisation des interventions, le rabattement en tranchées drainantes avec mélanges de biomasses était approximativement de 1,5 à deux fois supérieur au rabattement en drainage conventionnel. Cette étude nous permet de conclure que le drainage en tranchée drainante avec mélange de biomasses devrait être privilégié dans un sol organique peu profond à la place ou en même temps de diminuer de l’espacement entre les drains. / In Montérégie, histosols enable a productive vegetable crop. Once drained and cultivated, organic soils start decomposing and subside. This leads to a problematic drainage for two main reasons. Firstly, histosols are composed of very fine organic material which migrates to downward in the soil profile to form a moorsh layer, typically between 25 and 40 cm below the root zone, and of very low permeability. Secondly, Soil subsidence also becomes a problem when the depth of the soil profile is reduced to less than a meter, because soil composition below that depth is dominated by low permeability clays or impermeable coprogenic material. A solution is to fill the drainage trench with material with a better permeability such as a mix of organic soil and shredded biomass. However, such material if organic will also start decomposing and compacting. The first objective of this study was to assess the stability of different mixes by measuring changes in the saturated hydraulic conductivity during continuous drainage in soil columns containing different organic soil mixtures. The second objective was to model the effect of the presence of a drainage trench as compared to conventional drainage in a shallow organic soil profile, based on the parameters of a real field. Five different trenches filling treatments were tested (three mixes of degraded organic soil with shredded biomasses of willow, miscanthus and defibered pine, a coarse rope of coconut fiber acting as vertical drain and a control with degraded organic soil). The mixes were filled into 60 cm high PVC columns and then fully saturated. Steadystate saturated flow was imposed, and the saturated hydraulic conductivity measured at different time intervals. The modeling of the drainage situation was done on Hydrus. The Van Genuchten parameters were determined for the different mixes for draining trench with points on the retention curve and for the real field profile with data of water table height and drain flow. The mix with defibered pine was the most stable. The difference of hydraulic conductivity between the defibered pine conductivity and the other two biomass mixes was not significant, but the amount of water which passed through the columns for defibered pine was twice the amount of the other two. For the modeling of the drainage process, the water table drawdown in the drainage trench with biomass mixes was approximately 1.5 to twice the water table drawdown of the classical drainage. This study enables us to conclude that drainage trench is efficient with or without decreasing drain spacing in a shallow organic soil.

Thesis (M.S.)--Ohio State University, 1981. / Includes bibliographical references (leaves 89-91). Available online via OhioLINK's ETD Center

A deterministic computer model was developed to continuously simulate the runoff from surface and subsurface-drained fields in the St. Lawrence lowlands. The model simulates all of the major hydrologic and hydraulic processes occurring both above and below the ground. Input data requirements include hourly rainfall, daily potential evapotranspiration, soil physical properties, field dimensions, open channel geometry and drainage system specifications. / Events for the years 1978 to 1982 were simulated, to compare the runoff characteristics between 20 ha, clay loam, surface-drained and subsurface-drained fields. Further simulations were conducted to examine the hydrologic effects of wide-spaced, deep, parallel field ditches. / Hydrographs for the one-in-200-year storm were also simulated. All of the simulations confirmed that the peak flow rate on the subsurface-drained field was less than that of the surface-drained field. Longer times to peak and lag times occurred on the subsurface-drained field.

No description available.

The overall aim of this work is to determine the ability of several types of in-sewer flow regulator to limit and attenuate, in conjunction with some type of storage unit, the flow of stormwater into a sewer system. The intended result of these devices is the reduction of overland flooding and downstream surcharge during storm events. Various stormwater management (SWM) techniques, practised both in the UK and abroad, were reviewed with particular emphasis on attenuation and control. Several types of flow regulators were tested where the choice was based on their popularity (i.e orifice plates and vortex), and novelty (i.e self regulating valve and throttle hose). A full size laboratory rig was built to allow experimentation and comparison of in-situ performance of several flow regulators. This system was capable of generating flows of up to 100 I/s which was controlled by a pneumatic valve interfaced to a dedicated PC. The flow characteristics(discharge and upstream head) were measured efficiently and accurately by two ultrasonic sensors. Investigation of the blockage performance of the vortex flow regulators indicated that these devices retained gross solids at higher heads (i. e. after formation of vortex) which either caused increase in discharge (up to 25% for a given upstream head) or reduced the outlet area (i. e. blockages). In terms of head/discharge relationships, the SRV offered optimum performance with consistent and near constant outflow (discharge changing 3% over 1m change in head). Vortex devices exhibited a linear relationship which is attributed to small changes in the air-core diameter. Comparisons were also made on the performance of these devices in terms of outlet opening, storage and passage of gross solids. A theoretical model was developed for the vortex regulator by combining the hydraulic properties of the free vortex with Bernoulli's equation and applying the principle of maximum discharge. In this way discharge could be predicted for a vortex flow regulator with an inlet opening in terms of upstream head and geometry of the device. The model was calibrated using the laboratory data and verified against independent data sets on blocked devices and from external sources.

No description available.

No description available.

No description available.

Trois procédés innovants ont permis d’extraire sélectivement des peptides actifs d’un hydrolysat complexe issu de la protéolyse pepsique de l’hémoglobine bovine. Un premier procédé d’extraction biphasique assistée par des alkyl-sulfonates a permis de modifier l’affinité des peptides pour la phase organique par la formation de paires d’ions. Ces études des conditions d’extraction de peptides opioïdes hydrophobes ont permis la mise en œuvre d’un système d’extraction dans l’octan-1-ol supporté par un contacteur à membrane. Dans un deuxième temps, un procédé de moussage-drainage fut développé sur les propriétés tensioactives des peptides et a permis de fractionner la population peptidique pour isoler une fraction aux propriétés antibactériennes. L’optimisation par plans d’expériences a mis en avant l’influence de quatre paramètres majeurs (concentrations en hydrolysat et en sel, pH des solutions d’hydrolysat et de drainage) et a permis de multiplier par 3,4 l’enrichissement de cette fraction dans la solution récoltée. Enfin un procédé récemment développé, l’électrodialyse associée à des membranes d’ultrafiltration ayant pour seule force motrice la différence de potentiel électrique, a permis d’isoler une fraction peptidique cationique. L’étude du comportement en encrassement a révélé l’existence de phénomènes de répulsion de charges empêchant la récolte d’une fraction peptidique anionique et la formation d’agrégats hème-peptides colmatant de manière partiellement réversible les membranes d’ultrafiltration. / Three innovative processes allowed to extract selectively active peptides from a complex hydrolysate from the pepsic proteolysis of bovine haemoglobin. A first process of biphasic extraction assisted by alkyl-sulfonates allowed to modify the affinity of peptides for the organic phase by the formation of ion-pairs. These studies of conditions of extraction of opioid hydrophobe peptides allowed the implementation of a system of extraction in octan-1-ol supported by a membrane contactor. Secondly, a process of bubbling-draining was developed based on the surface tension properties of the peptides and allowed to split the peptidic population to isolate a fraction showing antibacterial properties. The optimization by experimental design advanced the influence of four major parameters (concentrations of hydrolysate and KCl, pH of solutions of hydrolysate and drainage) and allowed to multiply by 3,4 the enrichment of this fraction in the collected solution. Finally a process recently developed, the electrodialysis associated with ultrafiltration membranes having for only driving strength the difference of electric potential, allowed to isolate a cationic peptidic fraction. The study of the behavior in fouling revealed the existence of phenomena of charge repulsion preventing the isolation of a anionic peptidic fraction and the formation of aggregates haem-peptides fouling in a partially reversible way the ultrafiltration membranes.