The importance of utilizing different types of energy and their technical application is discussed. Awareness around the globe about the world energy crisis and its critical environmental condition has put more emphasis on the use of renewable energies in every corner of life. It is a well‐known fact that global warming, inefficient use of energy and greenhouse gases are damaging the environment, species and human life drastically. These issues will be discussed in recently conducted research. To address the crucial state of our environment, two simultaneous scenarios are considered. Initially, energy conservation and the switch to a low carbon/no carbon fuel are studied. As for energy conservation in buildings, smart methods in the use of energy in buildings are discussed. Based on different research reported, humans must change their attitude toward the use of resources, and in particular, be conscientious about energy consumption. Next, renewable energy promises a suitable alternative to energy needs in this century, and the best means to overcome the environmental issue and energy crisis is discussed. The practical methods of calculation for solar technology equipment, ground source heat pumps, and wind turbines are explained. In the application part of the study, four buildings are chosen as case studies; two of them from residential sectors, one is a commercial/institutional building, and the fourth is an industrial building. A ground source heat pump for heating and cooling, a solar water heater for heating space or hot water, and a photovoltaic panel for generating electricity are designed for the case studies. Even projects under hybrid systems combined from two technologies are designed. 36 different energy options are calculated for the four case studies. Results show that if a target is reducing CO2 emissions, what systems are the best. In contrast, when decision making is based on budget, what system is the first choice? Not only are technology, environmental protection and cost the main parameters for deciding on renewable technologies, but so are reliability, installation, maintenance and ease of use. Hence, renewable energy systems are categorized based on a broad vision.

Ground-level ozone (O3) is a familiar pollutant because it is associated with summer haze and smog alerts. The 2000-2008 weekday-weekend variations of ozone concentration were examined in relation to the Toronto weather conditions. The goal of this work is twofold: (1) To determine whether extreme ozone events were associated with specific weather conditions, (2) To determine whether the weekday-weekend effect of extreme ozone events could be detectable during the nine-year study period. The results show that in the study period, there were totally 313 days having extreme ground-level ozone events with ozone concentration ≥ 80 ppb, which is the current Ontario Ambient Air Quality Criterion for ozone concentration, in the four selected Toronto sites. Additionally, the weather condition mainly associated with these 313 days was the Dry Tropical one. This study also shows the phenomenon of the weekday-weekend effect of extreme ozone events in the past nine years in Toronto.

The influence of supplementary materials such as slag, metakaolin and limestone in steam-cured ternary and quaternary cement blends on physical and chemical hydration mechanisms was studied by analyzing the evolution of non-evaporable water content, hydration products and compressive strength. The role of limestone in hydration reactions of cement was also investigated. These properties were studied through the use of differential thermal and thermogravimetric analyses, as well as the loss-on-ignition, X-ray diffraction and compressive strength tests at 1, 3, 7, and 28 days. Research findings revealed that it is possible to replace up to 40% cement with other materials and still achieve compressive strengths similar to mixtures with a 25% cement replacement at 0.34 w/b ratio. Additionally, ternary limestone mixtures exhibited superior mechanical properties to ternary metakaolin mixtures. Lastly, limestone powder was determined to behave as inert filler, accelerating hydration at early ages through heterogeneous nucleation.

During several years research has been performed at the Department of Laser Systems, the Swedish Defense Research Agency (FOI), to develop methods to produce high resolution 3D environment models based on data acquired with airborne laser systems. The 3D models are used for several purposes, both military and civilian applications, for example mission planning, crisis management analysis and planning of infrastructure. We have implemented a new format to store laser point data. Instead of storing rasterized images of the data this new format stores the original location of each point. We have also implemented a new method to detect outliers, methods to estimate the ground surface and also to divide the remaining data into two classes: buildings and vegetation. It is also shown that it is possible to get more accurate results by analyzing the points directly instead of only using rasterized images and image processing algorithms. We show that these methods can be implemented without increasing the computational complexity.

Ground-level ozone (O3) is a familiar pollutant because it is associated with summer haze and smog alerts. The 2000-2008 weekday-weekend variations of ozone concentration were examined in relation to the Toronto weather conditions. The goal of this work is twofold: (1) To determine whether extreme ozone events were associated with specific weather conditions, (2) To determine whether the weekday-weekend effect of extreme ozone events could be detectable during the nine-year study period. The results show that in the study period, there were totally 313 days having extreme ground-level ozone events with ozone concentration ≥ 80 ppb, which is the current Ontario Ambient Air Quality Criterion for ozone concentration, in the four selected Toronto sites. Additionally, the weather condition mainly associated with these 313 days was the Dry Tropical one. This study also shows the phenomenon of the weekday-weekend effect of extreme ozone events in the past nine years in Toronto.

The influence of supplementary materials such as slag, metakaolin and limestone in steam-cured ternary and quaternary cement blends on physical and chemical hydration mechanisms was studied by analyzing the evolution of non-evaporable water content, hydration products and compressive strength. The role of limestone in hydration reactions of cement was also investigated. These properties were studied through the use of differential thermal and thermogravimetric analyses, as well as the loss-on-ignition, X-ray diffraction and compressive strength tests at 1, 3, 7, and 28 days. Research findings revealed that it is possible to replace up to 40% cement with other materials and still achieve compressive strengths similar to mixtures with a 25% cement replacement at 0.34 w/b ratio. Additionally, ternary limestone mixtures exhibited superior mechanical properties to ternary metakaolin mixtures. Lastly, limestone powder was determined to behave as inert filler, accelerating hydration at early ages through heterogeneous nucleation.

This thesis explores the experiences and practices of disaster relief volunteers. This thesis is based on ethnographic fieldwork conducted over a period of fifty-three days in the summer of 2007 at the post-hurricane Katrina Lower Ninth Ward of New Orleans, Louisiana. Through innovative practices and a commitment to the principle of “solidarity not charity” volunteers produce not just material aid, but an ideology of social justice. This thesis is also an exercise in engaged scholarship in that the author directly participated in the disaster relief effort as a volunteer.

Closed-loop ground source heat pumps (GSHPs) are used to transfer thermal energy between the subsurface and conditioned spaces for heating and cooling applications. A basic GSHP is composed of a ground heat exchanger (GHX), which is a closed loop of pipe buried in the shallow subsurface circulating a heat exchange fluid, connected to a heat pump. These systems offer an energy efficient alternative to conventional heating and cooling systems; however, installation costs are higher due to the additional cost associated with the GHX. By further developing our understanding of how these ground loops interact with the subsurface, it may possible to design them more intelligently, efficiently, and economically. To gain insight into the physical processes occurring between the GHX and the subsurface and to identify efficiencies and inefficiencies in GSHP design and operation, two main research goals were defined: comprehensive monitoring of a fully functioning GSHP and intensive simulation of these systems using computer models. A 6-ton GSHP was installed at a residence in Elora, ON. An array of 64 temperature sensors was installed on and surrounding the GHX and power consumption and temperature sensors were installed on the system inside the residence. The data collected were used to help characterize and understand the function of the system, provide motivation for further investigations, and assess the impact of the time of use billing scheme on GSHP operation costs. To simulate GSHPs, two computer models were utilized. A 3D finite element model was employed to analyse the effects of pipe configuration and pipe spacing on system performance. A unique, transient 1D finite difference heat conduction model was developed to simulate a single pipe in a U-tube shape with inter-pipe interactions and was benchmarked against a tested analytical solution. The model was used to compare quasi-steady state and transient simulation of GSHPs, identify system performance efficiencies through pump schedule optimization, and investigate the effect of pipe length on system performance. A comprehensive comparison of steady state and pulsed simulation concludes that it is possible to simulate transient operation using a steady state assumption for some cases. Optimal pipe configurations are identified for a range of soil thermal properties. Optimized pump schedules are identified and analysed for a specific heat pump and fluid circulation pump. Finally, the effect of pipe spacing and length on system performance is characterized. It was found that there are few design inefficiencies that could be easily addressed to improve general design practice.

Near-surface sediments in the vadose zone play a fundamental role in the hydrologic system. The shallow vadose zone can act as a buffer to delay or attenuate surface contaminants before they reach the water table. It also acts as a temporary soil moisture reservoir for plant and atmospheric uptake, and regulates the seasonal groundwater recharge process. Over the past few decades, geophysical methods have received unprecedented attention as an effective vadose zone characterization tool offering a range of non-invasive to minimally invasive techniques with the capacity to provide detailed soil moisture information at depths typically unattainable using conventional point-measurement sensors. Ground-penetrating radar (GPR) has received much of this attention due to its high sensitivity to the liquid water phase in geologic media. While much has been learned about GPR soil moisture monitoring and characterization techniques, it has not been evaluated across highly dynamic natural soil conditions. Consequently, GPR’s capacity to characterize a complete range of naturally occurring vadose zone conditions including wetting/drying and freeze/thaw cycles, is not yet fully understood. Further, the nature of GPR response during highly dynamic moisture periods has not been thoroughly investigated. The objective of this thesis is to examine the capacity of various surface GPR techniques and methodologies for the characterization of soil moisture dynamics in the upper few meters of vadose zone, and to develop measurement strategies capable of providing quantitative information about the current and future state of the shallow hydrologic system. To achieve this, an exhaustive soil moisture monitoring campaign employing a range of GPR antenna frequencies and survey acquisition geometries was initiated at three different agricultural field sites located in southern Ontario, Canada, between May 2006 and October 2008. This thesis represents the first attempt to evaluate multiple annual cycles of soil conditions and associated hydrological processes using high-frequency GPR measurements. Summaries of the seven major works embodied in this thesis are provided below. Direct ground wave (DGW) measurements obtained with GPR have been used in a number of previous studies to monitor volumetric water content changes in the root zone; however, these studies have involved controlled field experiments or measurements collected across limited ranges in soil moisture. To further investigate the capacity of the DGW method, multi-frequency (i.e., 225 MHz, 450 MHz and 900 MHz) common-midpoint (CMP) measurements were used to monitor a complete annual cycle of soil water content variations at three sites with different soil textures (i.e., sand, sandy loam and silt loam). CMP surveys permitted characterization of the nature and evolution of the near-surface electromagnetic wavefields, and their subsequent impact on DGW velocity measurements. GPR results showed significant temporal variations in both the near-surface wavefield and multi-frequency DGW velocities corresponding to both seasonal and shorter term variations in soil conditions. While all of the measurement sites displayed similar temporal responses, the rate and magnitude of these velocity variations corresponded to varying soil water contents which were primarily controlled by the soil textural properties. Overall, the DGW measurements obtained using higher frequency antennas were less impacted by near-surface wavefield interference due to their shorter signal pulse duration. The estimation of soil water content using GPR velocity requires an appropriate petrophysical relationship between the dielectric permittivity and volumetric water content of the soil. The ability of various empirical relationships, volumetric mixing formulae and effective medium approximations were evaluated to predict near-surface volumetric soil water content using high-frequency DGW velocity measurements obtained from CMP soundings. Measurements were collected using 225, 450 and 900 MHz antennas across sand, sandy loam and silt loam soil textures over a complete annual cycle of soil conditions. A lack of frequency dependence in the results indicated that frequency dispersion had minimal impact on the data set. However, the accuracy of soil water content predictions obtained from the various relationships ranged considerably. The best fitting relationships did exhibit some degree of textural bias that should be considered in the choice of petrophysical relationship for a given data set. Further improvements in water content estimates were obtained using a field calibrated third-order polynomial relationship and three-phase volumetric mixing formula. While DGW measurements provide valuable information within the root zone, the characterization of vertical moisture distribution and dynamics requires a different approach. A common approach utilizes normal-moveout (NMO) velocity analysis of CMP sounding data. To further examine this approach, an extensive field study using multi-frequency (i.e., 225 MHz, 450 MHz, 900 MHz) CMP soundings was conducted to monitor a complete annual cycle of vertical soil moisture conditions at the sand, sandy loam and silt loam sites. The use of NMO velocity analysis was examined for monitoring highly dynamic vertical soil moisture conditions consisting of wetting/drying and freeze/thaw cycles with varying degrees of magnitude and vertical velocity gradient. NMO velocity analysis was used to construct interval-velocity-depth models at a fixed location collected every 1 to 4 weeks. Time-lapse models were combined to construct temporal interval-velocity fields, which were converted into soil moisture content. These moisture fields were used to characterize the vertical distribution, and dynamics of soil moisture in the upper few meters of vadose zone. Although the use of multiple antenna frequencies provided varying investigation depths and vertical resolving capabilities, optimal characterization of soil moisture conditions was obtained with 900 MHz antennas. The integration of DGW and NMO velocity data from a single CMP sounding could be used to assess the nature of shallow soil moisture coupling with underlying vadose zone conditions; however, a more quantitative analyses of the surface moisture dynamics would require definitive knowledge of GPR sampling depth. Although surface techniques have been used by a number of previous researchers to characterize soil moisture content in the vadose zone, limited temporal sampling and low resolution near the surface in these studies impeded the quantitative analysis of vertical soil moisture distribution and its associated dynamics within the shallow subsurface. To further examine the capacity of surface GPR, an extensive 26 month field study was undertaken using concurrent high-frequency (i.e., 900 MHz) reflection profiling and CMP soundings to quantitatively monitor soil moisture distribution and dynamics within a sandy vadose zone environment. An analysis on the concurrent use of reflection and CMP measurements was conducted over two contrasting annual cycles of soil conditions. Reflection profiles provided high resolution traveltime data between four stratigraphic reflection events while cumulative results of the CMP sounding data set produced precise depth estimates for those reflecting interfaces, which were used to convert interval traveltime data into soil water content estimates. The downward propagation of episodic infiltration events associated with seasonal and transient conditions were well resolved by the GPR data. The GPR data also revealed variations in the nature of these infiltration events between contrasting annual cycles. The use of CMP soundings also permitted the determination of DGW velocities, which enabled better characterization of short-duration wetting/drying and freezing/thawing processes. This higher resolution information can be used to examine the nature of the coupling between shallow and deep moisture conditions. High-resolution surface GPR measurements were used to examine vertical soil moisture distribution and its associated dynamics within the shallow subsurface over a 26 month period. While the apparent ability of surface GPR methods to give high quality estimates of soil moisture distribution in the upper 3 meters of the vadose zone was demonstrated, the nature of these GPR-derived moisture data needed to be assessed in the context of other hydrological information. As a result, GPR soil moisture estimates were compared with predictions obtained from a well-accepted hydrological modeling package, HYDRUS-1D (Simunek et al., 2008). The nature of transient infiltration pulses, evapotranspiration episodes, and deep drainage patterns were examined by comparing them with vertical soil moisture flow simulations. Using laboratory derived soil hydraulic property information from soil samples and a number of simplifying assumptions about the system, very good agreement was achieved between measured and simulated soil moisture conditions without model calibration. The overall good agreement observed between forward simulations and field measurements over the vertical profile validated the capacity of surface GPR to provide detailed information about hydraulic state conditions in the upper few meters of vadose zone. A unique DGW propagation phenomenon was observed during early soil frost formation. High-frequency DGW measurements were used to monitor the seasonal development of a thin, high velocity frozen soil layer over a wet low velocity unfrozen substratum. During the freezing process, the progressive attenuation of a low velocity DGW and the subsequent development of a high velocity DGW were observed. Numerical simulations using GPRMAX2D (Giannopoulos, 2005) showed that low velocity DGW occurring after freezing commenced was due to energy leaking across the frozen layer from the spherical body wave in the unfrozen half space. This leaky phase progressively dissipated until the frozen layer reached a thickness equivalent to one quarter of the dominant wavelength in the frozen ground. The appearance of the high velocity DGW was governed by its destructive interference with the reflection events from the base of the frozen layer. This interference obscured the high velocity DGW until the frozen layer thickness reached one half of the dominant wavelength in the frozen ground. While GPR has been extensively used to study frozen soil conditions in alpine environments, its capacity to characterize highly dynamic shallow freeze-thaw processes typically observed in temperate environments is not well understood. High-frequency reflection profiles and CMP soundings were used to monitor the freezing and thawing process during the winter seasonal period at the sand and silt loam sites. Reflection profiles revealed the long-term development of a very shallow (<0.5 m) soil frost zone overlying unfrozen wet substratum. During the course of the winter season, long-term traveltime analysis yielded physical properties of the frozen and unfrozen layers as well as the spatial distribution of the base of the soil frost zone. Short-term shallow thawing events overlying frozen substratum formed a dispersive waveguide for both the CMP and reflection profile surveys. Inversion of the dispersive wavefields for the CMP data yielded physical property estimates for the thawed and frozen soils and thawed layer thickness. It was shown that GPR can be used to monitor very shallow freezing and thawing events by responding to changes in the relative dielectric permittivity of the soil water phase. The works embodied in this thesis demonstrate the effectiveness of high-frequency GPR as a non-invasive soil moisture monitoring tool under a full range of naturally occurring moisture conditions with the temporal and vertical resolution necessary to quantitatively examine shallow vadose zone moisture dynamics. Because this study encompassed an unprecedented range of naturally occurring soil conditions, including numerous short and long duration wetting/drying and freezing/thawing cycles, complex geophysical responses were observed during highly dynamic soil moisture processes. Analysis and interpretation of these geophysical responses yielded both qualitative and quantitative information about the state of the hydrologic system, and hence, provided a non-invasive means of characterizing soil moisture processes in shallow vadose zone environments. In the future, these GPR soil moisture monitoring strategies should be incorporated into advanced land-surface hydrological modeling studies to improve our understanding of shallow hydrologic systems and its impacts on groundwater resources.

Not Empty is a two- part exploration of the relationship between humans and nature. In this essay I intend to discuss the relationship Australian Aboriginal peoples have with their environment. Their many cultures are among the oldest surviving civilizations on the planet, and their natural history is rich and complex. I plan to compare the relationship Australian Aboriginal cultures have to their environment to that of a Western civilization, specifically the United States. Neither relationship is perfect, nor is one of them 'better.' Both have histories riddled with extinction, evolution, and the conquest of new lands. The struggle Aboriginal Australians experienced when first settling their new land is concurrent to the degradation occurring today by Western cultures, with some differences, including scale and speed.