Basic oxygen furnace (BOF) slag media were studied through a series of laboratory, modeling and field studies as a potential treatment material for use in on site wastewater disposal systems. Microsphere enumeration methodology was examined in a factorial experiment to evaluate the minimum density and minimum number of microspheres that should be counted to ensure accurate and precise estimations of concentration. The results suggest that to minimize variability at least 350 microspheres should be counted and a microsphere density of 25-40 microspheres field-1 is necessary. A review of existing methodologies for high-titer bacteriophage production was conducted and an amalgamation of existing methodologies was chosen that reliably achieves elevated concentration and ensures a purified suspension. A combination of batch and column studies was conducted to evaluate the removal of the bacteriophage, PRD-1, and virus-sized fluorescent microspheres by BOF media, and to delineate the relative contributions of the two principle attenuation processes, inactivation and attachment. In the batch studies, substantial removal of PRD-1 does not occur in the pH 7.6 and 9.5 suspensions, but at pH 11.4, removal of the virus was 2.1 log C/C0 day-1 for the first two days, followed by 0.124 log C/C0 day-1 over the subsequent 10 days. Two column studies were conducted after 60 and 300 days of saturation with artificial groundwater at a flow rate of 1 pore volume day-1 using two BOF mixtures. After 300 days of column saturation, microsphere concentrations approached input levels, indicating a removal of 0.1-0.2 log C/C0 and suggesting attachment processes were negligible. PRD-1 removal was more pronounced (1.0-1.5 log C/C0). The reduction of PRD-1 is likely the result of a combination of virus inactivation at elevated pH (10.6-11.4), and attachment processes. Geochemical factors controlling microsphere attachment were compared between the two sets of experiments after 60 and 300 days of column saturation. Differences in attachment efficiency may be due to higher influent DOC concentration in the second experiment, conversion of amorphous iron phases to more crystalline forms over time, reductive dissolution of preferable attachment sites on iron phases, or precipitation of calcite. Hydrus-1D, a one-dimensional numerical model, was used to quantify transport processes, inactivation and attachment/detachment, occurring in the column experiments by model inversion. Fitted microsphere breakthrough closely matched observed data, whereas PRD-1 breakthrough with realistic parameter values does not closely match the peaked nature of the observed curves. The model achieved improved fits for microsphere and PRD-1 breakthrough when both strongly- and weakly-binding sites are represented. A unique set of parameter estimates could not be determined because of overparameterization of the inverse modeling for the experimental systems. An alternative latrine incorporating BOF slag media was constructed in a periurban community located near São Paulo, Brazil. Pathogen indicator removal is approximately 4-5 orders of magnitude in less than one meter of vertical transport through the BOF slag media. In a control latrine, constructed with similar hydraulic characteristics and inert materials, comparable reductions in pathogenic indicators were observed over three meters of vertical transport.

It has long been known that any activity that results in changes in subsurface pressure, such as hydrocarbon production or waste or water reinjection, also causes underground deformations and movement, which can be described in terms of volumetric changes. Such deformations induce surface movement, which has a significant environmental impact. Induced surface deformations are measurable as vertical displacements; horizontal displacements; and tilts, which are the gradient of the surface deformation. The initial component of this study is a numerical model developed in C++ to predict and calculate surface deformations based on assumed subsurface volumetric changes occurring in a reservoir. The model is based on the unidirectional expansion technique using equations from Okada’s theory of dislocations (Okada, 1985). A second numerical model calculates subsurface volumetric changes based on surface deformation measurements, commonly referred to as solving for the inverse case. The inverse case is an ill-posed problem because the input is comprised of measured values that contain error. A regularization technique was therefore developed to help solve the ill-posed problem. A variety of surface deformation data sets were analyzed in order to determine the surface deformation input data that would produce the best solution and the optimum reconstruction of the initial subsurface volumetric changes. Tilt measurements, although very small, were found to be much better input than vertical displacement data for finding the inverse solution. Even in an ideal case with 0 % error, tilts result in a smaller RMSE (about 12 % smaller in the case studied) and thus a better resolution. In realistic cases with error, adding only 0.55 % of the maximum random error in the surface displacement data affects the back-calculated results to a significant extent: the RMSE increased by more than 13 times in the case studied. However, in an identical case using tilt measurements as input, adding 20 % of the maximum surface tilt value as random error increased the RMSE by 7 times, and remodelling the initial distribution of the volumetric changes in the subsurface was still possible. The required area of observation can also be reduced if tilt measurements are used. The optimal input includes tilt measurements in both directions: dz/dx and dz/dy. iv With respect to the number of observation points chosen, when tilts are used with an error of 0 %, very good resolution is obtainable using only 0.4 % of the unknowns as the number of benchmarks. For example, using only 10 observation points for a reservoir with 2500 elements, or unknowns resulted in an acceptable reconstruction. With respect to the sensitivity of the inverse solution to the depth of the reservoir and to the geometry of the observation grid, the deeper the reservoir, the more ill-posed the problem. The geometry of the benchmarks also has a significant effect on the solution of the inverse problem.

The initiation of subduction requires the formation of lithospheric plates which mostly deform at their edges. Shear heating is a possible candidate for producing such localized deformation. In this thesis we employ a 2D model of the mantle with a visco-elasto-plastic rheology and enabled shear heating. We are able to create a shear heating instability both in a constant strain rate and a constant stress boundary condition setup. For the rst case, localized deformation in our specic setup is found for strain rates of 10-15 1/s and mantle temperatures of 1300°C. For constant stress boundaries, the conditions for a setup to localize are more restrictive. Mantle motion is induced by large cold and hot temperature perturbations. Lithospheric stresses scale with the size of these perturbations; maximum stresses are on the order of the yield stress (1 GPa). Adding topography or large inhomogeneities does not result in lithospheric-scale fracture in our model. However, localized deformation does occur for a restricted parameter choice presented in this thesis. The perturbation size has little effect on the occurrence of localization, but large perturbations shorten its onset time.

Basic oxygen furnace (BOF) slag media were studied through a series of laboratory, modeling and field studies as a potential treatment material for use in on site wastewater disposal systems. Microsphere enumeration methodology was examined in a factorial experiment to evaluate the minimum density and minimum number of microspheres that should be counted to ensure accurate and precise estimations of concentration. The results suggest that to minimize variability at least 350 microspheres should be counted and a microsphere density of 25-40 microspheres field-1 is necessary. A review of existing methodologies for high-titer bacteriophage production was conducted and an amalgamation of existing methodologies was chosen that reliably achieves elevated concentration and ensures a purified suspension. A combination of batch and column studies was conducted to evaluate the removal of the bacteriophage, PRD-1, and virus-sized fluorescent microspheres by BOF media, and to delineate the relative contributions of the two principle attenuation processes, inactivation and attachment. In the batch studies, substantial removal of PRD-1 does not occur in the pH 7.6 and 9.5 suspensions, but at pH 11.4, removal of the virus was 2.1 log C/C0 day-1 for the first two days, followed by 0.124 log C/C0 day-1 over the subsequent 10 days. Two column studies were conducted after 60 and 300 days of saturation with artificial groundwater at a flow rate of 1 pore volume day-1 using two BOF mixtures. After 300 days of column saturation, microsphere concentrations approached input levels, indicating a removal of 0.1-0.2 log C/C0 and suggesting attachment processes were negligible. PRD-1 removal was more pronounced (1.0-1.5 log C/C0). The reduction of PRD-1 is likely the result of a combination of virus inactivation at elevated pH (10.6-11.4), and attachment processes. Geochemical factors controlling microsphere attachment were compared between the two sets of experiments after 60 and 300 days of column saturation. Differences in attachment efficiency may be due to higher influent DOC concentration in the second experiment, conversion of amorphous iron phases to more crystalline forms over time, reductive dissolution of preferable attachment sites on iron phases, or precipitation of calcite. Hydrus-1D, a one-dimensional numerical model, was used to quantify transport processes, inactivation and attachment/detachment, occurring in the column experiments by model inversion. Fitted microsphere breakthrough closely matched observed data, whereas PRD-1 breakthrough with realistic parameter values does not closely match the peaked nature of the observed curves. The model achieved improved fits for microsphere and PRD-1 breakthrough when both strongly- and weakly-binding sites are represented. A unique set of parameter estimates could not be determined because of overparameterization of the inverse modeling for the experimental systems. An alternative latrine incorporating BOF slag media was constructed in a periurban community located near São Paulo, Brazil. Pathogen indicator removal is approximately 4-5 orders of magnitude in less than one meter of vertical transport through the BOF slag media. In a control latrine, constructed with similar hydraulic characteristics and inert materials, comparable reductions in pathogenic indicators were observed over three meters of vertical transport.

It has long been known that any activity that results in changes in subsurface pressure, such as hydrocarbon production or waste or water reinjection, also causes underground deformations and movement, which can be described in terms of volumetric changes. Such deformations induce surface movement, which has a significant environmental impact. Induced surface deformations are measurable as vertical displacements; horizontal displacements; and tilts, which are the gradient of the surface deformation. The initial component of this study is a numerical model developed in C++ to predict and calculate surface deformations based on assumed subsurface volumetric changes occurring in a reservoir. The model is based on the unidirectional expansion technique using equations from Okada’s theory of dislocations (Okada, 1985). A second numerical model calculates subsurface volumetric changes based on surface deformation measurements, commonly referred to as solving for the inverse case. The inverse case is an ill-posed problem because the input is comprised of measured values that contain error. A regularization technique was therefore developed to help solve the ill-posed problem. A variety of surface deformation data sets were analyzed in order to determine the surface deformation input data that would produce the best solution and the optimum reconstruction of the initial subsurface volumetric changes. Tilt measurements, although very small, were found to be much better input than vertical displacement data for finding the inverse solution. Even in an ideal case with 0 % error, tilts result in a smaller RMSE (about 12 % smaller in the case studied) and thus a better resolution. In realistic cases with error, adding only 0.55 % of the maximum random error in the surface displacement data affects the back-calculated results to a significant extent: the RMSE increased by more than 13 times in the case studied. However, in an identical case using tilt measurements as input, adding 20 % of the maximum surface tilt value as random error increased the RMSE by 7 times, and remodelling the initial distribution of the volumetric changes in the subsurface was still possible. The required area of observation can also be reduced if tilt measurements are used. The optimal input includes tilt measurements in both directions: dz/dx and dz/dy. iv With respect to the number of observation points chosen, when tilts are used with an error of 0 %, very good resolution is obtainable using only 0.4 % of the unknowns as the number of benchmarks. For example, using only 10 observation points for a reservoir with 2500 elements, or unknowns resulted in an acceptable reconstruction. With respect to the sensitivity of the inverse solution to the depth of the reservoir and to the geometry of the observation grid, the deeper the reservoir, the more ill-posed the problem. The geometry of the benchmarks also has a significant effect on the solution of the inverse problem.

The general objective of the research effort reported in this thesis was to develop the knowledge required to optimize the design and operation of solid and semi-solid manure handling and land application equipment. Selected physical and rheological properties of manure products deemed to have an influence on the performances of manure handling and land application equipment were measured and general trends were identified among the measured properties. Relationships were also established between the measured properties and the type of manure as well as its total solids concentration. Field experiments were carried out to evaluate the effects of selected mechanical configurations, operating parameters and product properties on the discharge of manure spreaders. The influence of the type of conveying system (scraper conveyor and system of four augers) and the velocity at which it is operated, the geometry of the holding system and the position of a flow-control gate were all included in the analysis. The discharge rates of the machines as well as the specific energy required by the unloading operations were measured. A numerical modeling method called discrete element method (DEM) was used to create virtual manure, a numerical model of the real product. The measured physical and flow properties were used to develop and validate the virtual manure models. It was found that manure products could successfully be represented in a DE framework and that several parameters defining the contact constitutive model in the DEM had an influence on the behaviour of the virtual products. The DEM was then used to study machine-product interactions taking place in handling and land application equipment. Results from field experiments carried out using various land application equipment were used in the development and validation of the interaction models. The predicted flow rates and power requirements were in good agreement with measured data. The results obtained allowed for a better understanding of the flow of manure products in manure handling and land application equipment. It was found that the constitutive model used for the product influenced the results of the machine-product interactions models. A precision banded applicator under development at the University of Saskatchewan was also modeled. The discharge rate of this equipment is influenced by a number of parameters. The predicted mass distribution across the width of the banded applicator was well correlated to the experimental results. The models developed in this thesis have the potential to become powerful engineering tools for the design of improved machines for the handling and land application of solid and semi-solid manure.

Intraseasonal oscillations (ISOs) are important elements of the tropical climate with time-scales of 20-80 day. The ISO is poorly simulated and predicted by numerical models. This work presents a joint diagnostic and modeling study of the ISO that examines the hypothesis that local coupling between the ocean and the atmosphere is essential to the existence and evolution of the ISO in the Indo-Pacific warm pool region. Low-level moistening during the transition phase preconditions the atmosphere for deep convection. The vertical structure of ISO from the ECMWF coupled model during different phases of the oscillation as well as the skill of the model in simulating the processes that occur during the transition phase were studied. The forecast skill of the vertical structure associated with the ISO is greater for winter than for summer events. Predictability of the convective period is poor when initialized before the transitional phase. When initialized within the transition period including lower tropospheric moistening, predictability increases substantially, although the model parameterizations appears to trigger convection quickly without allowing an adequate buildup of CAPE during the transition. The model tends to simulate a more stable atmosphere compared to data, limiting the production of deep convective events. Two different one-dimensional coupled models are used to analyze the role of local ocean-atmosphere coupling in generating ISO. The ocean component is a one-dimensional mixed layer model. In the first model the atmospheric component corresponds to the SCCM. Results suggest that convection in the model tends to be "overactive," inhibiting development of lower frequency oscillations in the atmosphere. In the second case, the atmospheric component is a semi-empirical model that allows reproducing the coupled ISO over long integration periods including only local mechanisms. In the semi-empirical scheme the rate of change of atmospheric variables is statistically related to changes in SST. The stable state of this model is a quasi-periodic oscillation with a time scale between 25 and 80 days that matches well the observed ISO. Results suggest that the period of the oscillation depends on the characteristics of the ocean mixed layer, with a higher frequency oscillation for a shallow mixed layer.

The analytical and numerical modeling of CO2 sequestration in deep saline aquifers having different properties was studied with diffusion and convection mechanisms. The complete dissolution of CO2 in the aquifer by diffusion took thousands, even millions of years. In diffusion dominated system, an aquifer with 100 m thickness saturated with CO2 after 10,000,000 years. It was much earlier in convective dominant system. In diffusion process, the dissolution of CO2 in aquifer increased with porosity increase / however, in convection dominant process dissolution of CO2 in aquifer decreased with porosity increase. The increase in permeability accelerated the dissolution of CO2 in aquifer significantly, which was due to increasing velocity. The dissolution process in the aquifer realized faster for the aquifers with lower dispersivity. The results of convective dominant mechanism in aquifers with 1md and 10 md permeability values were so close to that of diffusion dominated system. For the aquifer having permeability higher than 10 md, the convection mechanism began to dominate gradually and it became fully convection dominated system for 50 md and higher permeability values. These results were also verified with calculated Rayleigh number and mixing zone lengths. The mixing zone length increased with increase in porosity and time in diffusion dominated system. However, the mixing zone length decreased with increase in porosity and it increased with increase in dispersivity and permeability higher than 10 md in convection dominated system.

This research is dedicated to make a foreseeing of the future state of the Kizildere Geothermal Field in order to suggest acceptable solutions to the current problems. The non-isothermal mechanism of the geothermal field is simulated for the pressure and temperature variables. For this purpose, a finite element model (696 four-nodal elements with 750 nodes) of the field is formulated by considering the geological conditions and the present wells already drilled in the area. Then the model is calibrated to the field for the natural state by using appropriate physical properties, boundary and initial conditions. Comparison of the simulated and the observed pressures and temperatures has emphasized a very successful calibration study. After the calibration, response of the field to the production and injection for the period of 1984-2006 has been simulated by applying a history matching study. History matching runs have yielded very good correlations between the observed and the computed values of the pressure and temperature variables. The calibrated and history matched model has been applied to the field to simulate the future performance of the field for different production and injection scenarios. In the first scenario the field is simulated for the next 10-year production period keeping the on-going production conditions. Then, the influence of the production of two new wells has been investigated in two different scenarios. In the forth scenario, the effect of injection from one of the production wells has been simulated.

The purpose of this study is the characterization and modeling of Ulubey aquifer system which serves as an important water supply for USak province located in inner parts of the Aegean Region in Turkey. In recent years, growing population, accelarating industrial activities and on the contrary decreasing rainfall and contamination of the surface water resources made groundwater indispensable to meet domestic, agricultural and industrial water demands of USak province. All these facts necessitate the development of a groundwater management plan, which this study aims to end up with. For this purpose, every single component of the recharge/discharge mechanisms of the groundwater budget of the aquifer system should conceptually be comprehended. However, due to lack of data, all of the components can not be precisely determined. Hence, a mathematical groundwater flow model successfully calibrated under steady state conditions, is utilized to calculate the missing components of the groundwater budget and also to test the effects of increased pumping rates for irrigational and domestic uses to supply the increasing demand in the future. For this purpose, three management scenarios are set up under transient conditions over a planning period of 20 years. Drawdown maps, groundwater budgets and groundwater level hydrographs are utilized to observe the effects. The results of these simulations proved that neither of the tested management scenarios creates significant drawdowns or change in groundwater reserve of the Ulubey aquifer system.