<p>The objective of this research was to develop and calibrate a dynamic mechanistic model for biological nutrient (nitrogen and phosphorus) removal activated sludge systems treating municipal wastewater. The IAWPRC (ASM1) model for non-polyP heterotrophic and autotrophic organisms (Henze et al., 1987a,b) and the Wentzel et al. (1989b) model for polyP organisms were merged to form a general activated sludge model. After a number of initial modifications the model was tested against literature data from laboratory-scale nitrification denitrification biological excess phosphorus removal (NDBEPR) systems. Based on the preliminary results, a number of specific areas were identified which required further study. These included (1) accounting for sludge production and oxygen utilization in BEPR systems; (2) denitrification behaviour in BEPR systems; and (3) other issues such as hydrolysis under unaerated conditions.</p> <p>The main body of this thesis is presented as a series of five papers. The first paper (Chapter 4) presents a study of COD and nitrogen balances in activated sludge systems. The results suggest that systems incorporating anaerobic zones exhibit low COD balances compared to aerobic and anoxic-aerobic systems. Possible mechanisms for this "loss" of COD are discussed, including the possibility that the COD loss is related to fermentation processes occurring under anaerobic conditions.</p> <p>The second paper (Chapter 5) presents a study of denitrification behaviour in BEPR activated sludge systems. Results of a review of microbiological studies and many continuous and batch reactor experimental studies indicate that a significant fraction of the polyP organisms can use nitrate as an electron acceptor in the absence of oxygen for oxidation of stored PHB and simultaneous uptake of phosphorus.</p> <p>The development of a general activated sludge model for biological nutrient removal activated sludge systems is discussed in the third paper (Chapter 6). Several modifications were made to both the ASM1 and Wentzel et al. (1989b) model components, based on the results of literature review and model simulations. A fermentation process has been included for the conversion of readily biodegradable COD to short chain fatty acids (assuming a loss of COD). Hydrolysis of enmeshed slowly biodegradable COD under anaerobic conditions has been incorporated, as well as anoxic growth of polyP organisms. These modifications and others are discussed in this paper. The matrix representation and a description of the model processes are also presented, as well as a brief outline of influent wastewater characterization.</p> <p>The application of the general model is demonstrated in the fourth paper (Chapter 7) for aerobic and anoxic-aerobic systems, as well as a number of nutrient removal (NDBEPR) systems for both steady state and dynamic conditions. Results of simulations show the model is capable of predicting sludge production and oxygen utilization for a range of system types and configurations, as well as tracking changes in a number of parameters including soluble phosphorus and nitrate concentrations.</p> <p>In the final paper (Chapter 8) the consequences of the COD loss assumptions incorporated in the model are demonstrated for a number of experimental anoxic-aerobic and anaerobic-anoxic-aerobic systems. Results of model simulations indicate that without the assumption of COD loss, predictions of oxygen consumption and volatile suspended solids production are significantly over-estimated for NDBEPR systems (and to a lesser extent anoxic-aerobic systems). These systems apparently consume less oxygen and produce less volatile solids than aerobic systems for the same amount of COD removal.</p> <p>In conclusion, the merits and weaknesses of the general model are discussed. An important feature of the model is that a single set of kinetic and stoichiometric parameters produced quite accurate predictions for the wide range of systems to which the model was applied (with the exception of the nitrifier growth rate - discussed in Chapter 6). This provides a degree of support for the model structure and integrity. Many aspects of NDBEPR modelling require further investigation, including: the COD loss phenomenon, the fermentation processes occurring under anaerobic (and possibly anoxic) conditions, the hydrolysis of slowly biodegradable colloidal and particulate organics (particularly under anoxic and anaerobic conditions), and the impact these aspects have on denitrification behaviour in NDBEPR systems.</p> / Doctor of Philosophy (PhD)

<p>The scope of this thesis is to present a framework for the modelling of two-component, liquid/solid mixtures using the finite element method. The presentation is applicable to a wide range of two-component phenomena, however, special attention is paid to the liquefaction of sandy soils which is of particular concern to the civil engineer. In the past, much of the focus of research has been placed on the creation of models capable of capturing the mechanism of excess pore pressure development leading to liquefaction. Comparatively little attention has been placed on modelling the post-liquefaction event. This thesis provides a framework that allows the civil engineer to model soil deposits, predicting the onset of liquefaction and simulating the events that follow, namely post-liquefaction flow and the reconsolidation of the soil. The mixtures considered in this thesis are treated as two viscous fluids having momentum exchange between them via hydrodynamic drag. Two sets of Navier-Stokes equations are used to model the two-component mixture. The thesis presents the derivation of these equations along with the closure equations required to model the hydrodynamic drag and shear stress constitutive behaviour. A simple, novel approach to modelling the compaction/dilation behaviour of granular materials under the action of shear strain is also presented. It is shown that a recasting of the equations with anew set of variables is helpful in solving the equations via standard Galerkin finite element methods. An outgrowth of this recasting is also presented, that allows, for one-dimensional problems, to reduce the variable set from four unknowns to one, greatly simplifying the solution process and computation effort. Finally, several applications of the model are presented in order to validate the model and to demonstrate the wide range for which the model may be used.</p> / Doctor of Philosophy (PhD)

<p>This thesis presents a comprehensive approach to numerical modelling of human bone. Bone has been shown, in general, to be a heterogeneous material with orthotropic symmetry. The geometric arrangement of its porous micro-structure can be detected by high resolution tomographic imaging and then characterized by a 'fabric tensor.' This tensorial measure of material fabric can be correlated with mechanical properties and subsequently employed within numerical analyses of bone. In this work, the fabric tensor is incorporated into an elastic constitutive framework and a novel failure criterion for bone is proposed, which is seen as an important contribution to the numerical analysis of bone within the finite element (FE) methodology. The identification of fabric from micro-computed tomography (micro-CT) images of representative bone samples is achieved by a unified computational framework, described by a language independent pseudo-code. As a contribution to the constitutive representation of bone material, a new measure of fabric is defined and then identified using synthetic data of simple geometric shapes and micro-CT scans of human trabecular bone. The current potential for improvement in FE modelling of the mechanical behaviour of bone is illustrated through a discussion of bone fracture. The numerical analysis is an extension of the results presented in Pietruszczak et al. (1997, 1999) wherein a high resolution geometric model with heterogeneous distribution of orientation-dependent mechanical properties was employed. The use of the material model within a FE analysis is illustrated by a FE analysis pertaining to the prediction of fracture within a femur, under the simulated conditions of a fall to the hip. In particular, the distribution of damage within a femur is assessed under two porosity distributions, simulating a healthy and an aged bone.</p> / Doctor of Philosophy (PhD)

<p>This research uses Geographic Information System (GIS) databases to manipulate the actual travel routes used by urban commuter cyclists to address issues related to bicycle route choice and bicycle safely.</p> <p>Chapter 2 compares previously collected routes from Guelph to the shortest path routes. Most commuters divert little (0.4 km on average) and use major road routes. Although the cyclists tend to avoid grades, grade-separated railway crossings and high activity areas, they do not avoid high speed traffic or bridges. The cyclists use traffic signals especially for crossing major roadways and for turning. High-quality off-road paths are used infrequently, the lower quality ones even less.</p> <p>Chapter 3 uses a logit model for route choice. The choice set determination is critical logic that checks alternative routes for duplication of attribute combinations is used. A multinomial logit model that exhibited independence from irrelevant alternatives is estimated. The model identifies route attributes similar to those described above. In addition, personal variables (age, gender, winter cycling) were found to be significant.</p> <p>Chapter 4 describes the survey methodology used to collect two larger commuter bicycle route datasets in Toronto and Ottawa. Questionnaires containing a map for route collection as well as questions relating to cycling patterns and accident history were placed on cross-bars of parked bicycles. The return rate was 47% of the 6043 questionnaires.</p> <p>The overall rates per 100,000 commuter kilometres of collisions, falls, injuries and major injuries were found to be 3.26, 9.51, 7.60 and 1.10 respectively (Chapter 5). These are approximately 10 times comparable rates for automobiles. The GIS was used to determine the distance in the regular route that was undertaken on-road, off-road or on sidewalks in the Ottawa study area. Collision rates on different infrastructure were not statistically different. However, injury and fall rates were highest on sidewalks (4 times that of roads) followed by off-road paths (1.6 times that of roads).</p> / Doctor of Philosophy (PhD)

<p>There are many existing buildings which have been designed according to earlier codes. In these codes, either design for seismic loads was not a requirement or design was for lower levels of seismic forces. One of the major challenges that faces structural engineers is to determine the seismic capacity of an existing building and to rehabilitate these buildings to upgrade their seismic capacity if needed. At present, there are no guidelines available for the rehabilitation of existing structures and for the design of different retrofitting techniques. One of the most effective ways of rehabilitation is the addition of reinforced concrete (RC) walls. Until now, there is no robust analytical model available to study the effect of adding RC walls on the building behaviour up to failure. To determine the building seismic capacity and to study the effect of adding RC walls, the analytical model used should be capable of representing all the deficiencies in existing buildings. Moreover, it should be able to represent all possible failure modes such as beam-column joint shear failure, cumulative concrete crushing and bond slip failure. The objective of the present research is to evaluate the behaviour of buildings retrofitted by the addition of reinforced concrete structural walls. This was done by the development of a suitable analytical model that fully describes the behaviour of existing buildings before and after rehabilitation using RC structural walls. This model was verified using test results on specimens representing existing structures and found to give results that are closely correlated to the experimental results. The model was able to detect the failure mechanisms observed in the experiments. This model was used in the analysis of an existing three-storey building to determine its seismic capacity. The effect of ignoring the beam-column joint shear deformations, bond slip and concrete crushing was studied. Ignoring any of these parameters can change the building failure mechanism which could lead to misleading results. After that, a suitable rehabilitation technique using RC walls was chosen and the building behaviour after rehabilitation was studied.</p> / Doctor of Philosophy (PhD)

<p>Curbside collection of municipal solid waste is an expensive and increasingly complex operation. Municipalities across North America have been expanding their waste collection fleets steadily over the past decade due to population growth, the introduction of new collection services such as curbside recycling, and a decline in the number of active landfill sites. Despite the increasing cost and complexity of municipal solid waste collection systems, many collection programs are designed and operated without a clear understanding of the parameters responsible for those costs or the relationships between those parameters. Existing models of municipal waste collection operations often deal only with average system performance, ignoring large variations in important parameters such as the quantity of waste set out for collection or the percentage of households participating in a collection program. This research develops two different analytic models of municipal solid waste collection that explicitly address the variability of municipal solid waste collection operations. The first model is based on probability theory and vehicle dynamics, while the second model is based on queuing theory. Despite different starting assumptions, both models provide similar results and both models agree well with Monte Carlo computer simulation results. Both models are easier to use than computer simulations of the waste collection process, can be applied to any municipal waste collection operation, and can be coded on spreadsheets. The potential utility of the developed models has been demonstrated by application to a number of practical municipal solid waste collection problems. The models are not used to optimize systems of collection vehicles in this research, although they are used to generate improved strategies for the specific problems presented. However, either of the two models could be further incorporated into large scale optimization models for complete waste management systems. The models are of interest primarily to solid waste management practitioners. It is anticipated that they would make use of the models both to design new collection systems and to improve existing collection operations. Application of the models to local design and operational problems should result in more efficient and less costly waste collection operations. Specifically, these models can be used to minimize the size of the collection fleet and the amount of time required to collect municipal solid wastes, resulting in lower capital and operating costs, lower fuel consumption, and reduced air emissions from collection vehicles.</p> / Doctor of Philosophy (PhD)

<p>A method is developed for the analysis of two-span continuous composite beams in both elastic and inelastic ranges. A computer program is also formed as an integral part of this study. In order to verify the analysis and the computer program, three test beams were chosen as examples for computation. The computed results and the test results are in good agreement.</p> / Master of Engineering (ME)

<p>The discrepancy between the quantity and regime of water consumption and natural river flow usually gives rise to the need to create a multi-reservoir inter-basin water resource system to redistribute the river flow temporally and spatially. As the economic value of water increases and inexpensive sources of water supply diminish, the development of an optimal operation management model becomes more and more important.</p> <p>In this thesis, a stochastic operation management model composing of two integrated models of stochastic multi-site flow generation model and deterministic Dynamic Programming optimization model is developed to determine the optimal operation of a multi-reservoir inter-basin water resource system. The stochastic multi-site flow generation model is used to generate synthetic now series as input to the optimization model. In this model. the stochastic nature of historical flows to reservoirs, i.e. auto-correlation and cross-correlation, is explicitly considered. The deterministic Dynamic Programming optimization model is developed to determine the optimum operation policies for each of the many synthetic flow series through application of the optimization model to the multi-reservoir inter-basin water resource system. The approach of separating these two models will overcome the curse of dimensionality encountered in existing DP optimization models while allowing the stochastic nature of inflows to be incorporated into the optimization process and resulting optimum operation policies.</p> <p>The real case study approach, selection criteria and description of case study area, Lar-Kalan-Latian water resource system in Tehran, Iran as a multireservoir inter-basin water resource system is discussed. The superiority of a real case study in comparison with a hypothetical or abstract one is demonstrated.</p> <p>A comprehensive review and identification of stochastic multi-site now generation models and discussion of available flow generation computer programs are presented. The statistical analysis of historical monthly and annual now data of the case study, setting up of HEC-4 program as direct method and SPIGOT program as disaggregation technique, and generation and verification of synthetic monthly and annual flow series for the case study are discussed. The comparison of HEC-4 and SPIGOT synthetic flow series with historical data shows the effectiveness of SPIGOT program against HEC-4, even for the short historical flow input data.</p> <p>A detailed review and discussion of the Dynamic Programming techniques and development of deterministic DP optimization model for the multi-reservoir inter-basin water resource system is carried out. The generation, comparison, statistical analysis, and reliability characteristics of optimum monthly operation polices determine by applying the developed DP optimization model is discussed. The comparison of optimum operation with historical operation demonstrates the usefulness and improvement of optimum operation upon historical operation. It is further concluded that the DP optimization model is not sensitive to the type of stochastic flow generation model used to generate synthetic flows. Finally, the development of optimum operation reliability characteristics demonstrates the application ofstochastic operation management model in planning and operation of multi-reservoir inter-basin water resource system.</p> / Doctor of Philosophy (PhD)

<p>In this project, the behaviour of brick masonry under various states of stress is discussed. These stress states include: axial compression, eccentric compression, flexure and in-plane shear. In addition, the creep and shrinkage characteristics of brickwork and the effect of grouting on the axial capacity of brick masonry assemblages are investigated on a preliminary basis. Comprehensive literature reviews and results of accompanying series of tests are presented and discussed.</p> / Master of Engineering (ME)

<p>Despite its popularity over the past 55 years, suburban sprawl development is widely criticized in the planning literature. Suburban sprawl is automobile dependent, socially segregating, and overly consumptive of raw materials, land and energy. Typically constructed at densities that do not support effective transit systems, suburban sprawl is often viewed as an unsustainable development form. Interest in urban sustainability evolved following the publication of Our Common Future in 1987, such that many communities now have vision statements and objectives for achieving sustainable community designs. There also has been a revival of neo-traditional planning concepts for the design and construction of new neighbourhoods to resemble those constructed prior to WWII (a period of lesser automobile dependence). Despite these efforts, there are many existing suburban areas surrounding cities in North America that need retrofitting, so that they may become increasingly sustainable. This dissertation develops a conceptual model providing decision support for suburban retrofitting, with the intent that the retrofitted suburbs exhibit a greater degree of sustainability than existing conventional suburban developments. This model, applicable at the neighbourhood scale, represents a departure from current sustainable community planning which is more focussed on greenfield developments. The conceptual model provides retrofitting methodologies for nine aspects of conventional suburban development, including those for increased density, added commerce and employment components, and reduced water, energy and material consumption. Automobile dependence is, in part, addressed by enhancing pedestrian networks and the implementation of neighbourhood traffic calming measures. Three prototype decision support tools have been created to assist a municipal planner or engineer in retrofitting a conventional suburban neighbourhood. These tools could be used at various stages within the planning process: (1) during the development or review of a community's Official Plan; (2) at the time of major street or utility reconstruction (to coincide with traffic calming installation); or (3) when more modest alterations to the neighbourhood are being considered (e.g., addition of street trees or pedestrian paths). The decision support tools can be used independently to model specific retrofitting aspects of neighbourhoods that may be of current interest to planners (e.g., traffic calming). When integrated with one another, they could be used to develop strategies for how a city might incorporate future population growth within existing built up areas, thereby maintaining a strict urban growth boundary. The prototype decision support tools are compiled for use in ArcView GIS and allow the user to generate and evaluate retrofitting scenarios for pedestrian connectivity, neighbourhood traffic calming and neighbourhood greening. GIS is the most suitable framework for these tools as it is a primary component in neighbourhood and regional planning processes. Sample applications are provided for case study neighbourhoods in Hamilton, Ontario to demonstrate the use of these tools, particularly to illustrate the key benefits one can achieve by retrofitting conventional suburban areas.</p> / Doctor of Philosophy (PhD)