Image guided radiation therapy (IGRT) is a new type of radiotherapy used to deliver lethal doses of radiation to mobile tumors, while preventing surrounding healthy structures from receiving high doses of radiation. It relies on image guidance to track the tumor and ensure its prescribed position in the radiation beam. The main goal of this work was to determine if a new three-dimensional ultrasound (3D US) image guidance device, called the Restitu System, could safely replace (or be used interchangeably with) an existing method involving x-ray images of implanted fiducial markers (FMs) for prostate IGRT. Using comparison statistics called 95 % limits of agreement (LOA), it was found that the new 3D US system did not produce measurements that agreed sufficiently closely to those made using the FM technique, and therefore, could not safely replace FMs for prostate IGRT. Ultrasound image quality and user variability were determined to have a significant impact on the agreement between the two methods. It was further shown that using the Restitu System offered no significant clinical advantages over a conventional patient re-positioning technique.

The principal observational contribution of this thesis is an innovative technique, using spatially resolved spectroscopy of highly magnified, gravitationally lensed galaxies, to study their internal structure and kinematics at redshift, z≥1 on sub-galactic scales. The scientific objective is to measure the important, but poorly understood, role of star formation and associated feedback on galaxy evolution. With Gemini GMOS-IFU observations of CFRS03+1077, a lensed galaxy at z=2.94, we determined surface brightness and integration time requirements for spatially resolved kinematics with spectra in the visible region (< 1 micron). For reasonable exposure times the presence of a strong emission line is key, limiting the redshift range to < 1.5 for [OII]3727Å. To tackle the lack of suitable lenses for such studies, we designed a lens search algorithm suitable for multi-color photometric data (with a minimum of 2 colors). Our method uses a two-step approach, first automatically identifying galaxy clusters and groups as high likelihood lensing regions, followed by a dedicated visual search for lensed arcs in pseudo-color images of sub-regions centered on these candidates. By using the color-position clustering of elliptical galaxies in high density environments, the algorithm efficiently isolates candidates with a completeness ≥ 80% for z ≤ 0.6 in Monte-Carlo simulations. Implemented on the CFHT Legacy Survey-Wide fields with available g, r and i photometry, the present yield is 9 lenses (8 new and 1 previously known) from 104 deg². With Gemini GMOS, we confirmed two lensed galaxies with strong [OII]3727Å emission suitable for IFU spectroscopy. The follow-up of both systems, the confirmation of remaining lenses and the application of the lens detector to the remaining 91 square degrees of CFHTLS-Wide are ongoing. In a complementary project, we aim to understand non-linear structure formation within the Λ-CDM framework by characterizing the mass distributions and mass/light ratios of galaxy groups; these structures (where 60% of all galaxies reside), have masses representative of the critical break between cluster and field galaxy mass scales. We use strong gravitational lensing to constrain the mass in the inner core, with velocity dispersion measurements from MOS spectroscopy to map the mass distribution up to the scale of the virial radius. The formalism supporting this approach as well as the tools for analysis (including an efficient B-spline based method for flat fielding and sky subtraction of sky limited spectra) are presented in this thesis. The deflectors of 6 lenses in our catalog resemble galaxy groups suitable for this study. One group, for which the observations are complete, is compatible with either NFW or Hernquist profile; these results will be corroborated with observations of other candidates in forthcoming observing programs. The objective is to amalgamate our results with mass measurements from weak lensing and X-ray observations from our Strong Lensing Legacy Survey (SL2S) collaborators to build a comprehensive picture of the dark matter profile and thus constrain theoretical predictions of mass assembly in galaxy groups.

This thesis presents a simulation of the control system for Laser Guide Star (LGS) wavefront sensing of the Narrow Field Infrared Adaptive Optics System (NFIRAOS) which will be the Adaptive Optics (AO) system on the Thirty Meter Telescope. The control system is multirate and combines data from multiple sources, both natural and artificial, to provide wavefront correction. Artificial guide stars are generated by exciting atoms in the mesospheric sodium (Na) layer. The characteristics of the Na layer have been examined; its variability, altitude and thickness will lead to false atmospheric turbulence measurements by AO systems integrated with Extremely Large Telescopes. A periodically updated constrained matched filter algorithm has been implemented in the control system simulation in order to gauge its ability to mitigate these effects. The control system has also been implemented on the University of Victoria LGS Test Bench which reproduces wavefront measurements as they will be made by several of the wavefront sensors of NFIRAOS. The simulation has provided insight into the stability of the proposed control system and allowed necessary improvements to be made. It has been shown to meet the requirements of stability over long term with fast convergence. The matched filter algorithm has been shown to effectively reject the Na layer fluctuations both in simulation and on the test bench.

The Square Kilometer Array radio astronomy telescope will achieve the majority of its extremely large aperture area with thousands of parabolic dishes, each illuminated by a wideband antenna feed, and this thesis introduces a new such antenna. The wide bandwidth of this new antenna is achieved with the development of a directional log periodic antenna. Scaling the log periodic elements into three-dimensional space is the present method used for directional log periodic antennas. We propose confining these often complex log periodic elements into a single plane, while the ground "plane" takes on a three dimensional form, permitting low-cost implementations without requiring the introduction of a complicated scaffolding to support the log periodic elements in 3-D. This low-cost solution would scale well in the implementation of the thousands of antenna feeds that the Square Kilometer Array demands. We also introduce a previously unreported LP design: the log periodic log spiral antenna.

The formation of modern society has been dominated by coal and oil, and together these two fossil fuels account for nearly two thirds of all primary energy used by mankind.  This makes future production a key question for future social development and this thesis attempts to answer whether it is possible to rely on an assumption of ever increasing production of coal and oil. Both coal and oil are finite resources, created over long time scales by geological processes. It is thus impossible to extract more fossil fuels than geologically available. In other words, there are limits to growth imposed by nature. The concept of depletion and exhaustion of recoverable resources is a fundamental question for the future extraction of coal and oil. Historical experience shows that peaking is a well established phenomenon in production of various natural resources. Coal and oil are no exceptions, and historical data shows that easily exploitable resources are exhausted while more challenging deposits are left for the future. For oil, depletion can also be tied directly to the physical laws governing fluid flows in reservoirs. Understanding and predicting behaviour of individual fields, in particularly giant fields, are essential for understanding future production. Based on comprehensive databases with reserve and production data for hundreds of oilfields, typical patterns were found. Alternatively, depletion can manifest itself indirectly through various mechanisms. This has been studied for coal. Over 60% of the global crude oil production is derived from only around 330 giant oilfields, where many of them are becoming increasingly mature. The annual decline in existing oil production has been determined to be around 6% and it is unrealistic that this will be offset by new field developments, additional discoveries or unconventional oil. This implies that the peak of the oil age is here. For coal a similar picture emerges, where 90% of the global coal production originates from only 6 countries. Some of them, such as the USA show signs of increasing maturity and exhaustion of the recoverable amounts. However, there is a greater uncertainty about the recoverable reserves and coal production may yield a global maximum somewhere between 2030 and 2060. This analysis shows that the global production peaks of both oil and coal can be expected comparatively soon. This has significant consequences for the global energy supply and society, economy and environment. The results of this thesis indicate that these challenges should not be taken lightly.

Oil is the black blood that runs through the veins of the modern global energy system. While being the dominant source of energy, oil has also brought wealth and power to the western world. Future supply for oil is unsure or even expected to decrease due to limitations imposed by peak oil. Energy is fundamental to all parts of society. The enormous growth and development of society in the last two-hundred years has been driven by rapid increase in the extraction of fossil fuels. In the foresee-able future, the majority of energy will still come from fossil fuels. Consequently, reliable methods for forecasting their production, especially crude oil, are crucial. Forecasting crude oil production can be done in many different ways, but in order to provide realistic outlooks, one must be mindful of the physical laws that affect extraction of hydrocarbons from a reser-voir. Decline curve analysis is a long established tool for developing future outlooks for oil production from an individual well or an entire oilfield. Depletion has a fundamental role in the extraction of finite resources and is one of the driving mechanisms for oil flows within a reservoir. Depletion rate also can be connected to decline curves. Consequently, depletion analysis is a useful tool for analysis and forecasting crude oil production. Based on comprehensive databases with reserve and production data for hundreds of oil fields, it has been possible to identify typical behaviours and properties. Using a combination of depletion and decline rate analysis gives a better tool for describing future oil production on a field-by-field level. Reliable and reasonable forecasts are essential for planning and nec-essary in order to understand likely future world oil production.

As an operational approach to the Bekenstein-Hawking formula S_{BH}=A/4l_{Pl}^{2} for the black hole entropy, we consider the reversible contraction of a spinning thin shell to its event horizon and find that its thermodynamic entropy approaches $S_{\mathrm{BH}}$. In this sense the shell, called a "black shell", imitates and is externally indistinguishable from a black hole. Our work is a generalization of the previous result [10] for the spherical case. We assume the exterior space-time of the shell is given by the Kerr metric and match it to two different interior metrics, a vacuum one and a non-vacuum one. We find the vacuum interior embedding breaks down for fast spinning shells. The mechanism is not clear and worth further exploring. We also examine the case of a Kerr-AdS exterior, without trying to find a detailed interior solution. We expect the same behavior of the shell when the horizon limit is approached.

Raman spectroscopy is a form of vibrational spectroscopy that is capable of probing biological samples at a molecular level. In this work it was used in the analysis of ionizing radiation-induced damage in DNA. Spectra of both simple, short-stranded DNA oligomers (SS-DNA) and the more complicated calf-thymus DNA (CT-DNA) were acquired before and after irradiation to a variety of doses from 0 to ~2000 Gy. In a technique known as ultraviolet resonance Raman spectroscopy (UVRRS), three UV wavelengths of 248, 257 and 264 nm were utilized in order to selectively enhance contributions from different molecular groups within the samples. Assignment of the spectral peaks was aided by the literature, as well as through analysis of UVRR spectra of short strands of the individual DNA bases obtained at each of the three incident UV wavelengths. Difference spectra between the irradiated and unirradiated samples were calculated and the samples exposed to ~2000 Gy showed significant radiation-induced features. Intensity increases of spectral peaks, observed primarily in the CT-DNA, indicated unstacking of the DNA bases and disruption of Watson-Crick hydrogen bonds, while intensity decreases of spectral peaks, observed only in the SS-DNA, indicated both base damage and the loss of structural integrity of the DNA molecule. The high molecular specificity of UVRRS allowed for precise identification of the specific bonds affected by the radiation, and the use of the varying incident wavelengths allowed for the observation of damage to moieties that would otherwise have been excluded. The use of UVRRS shows promise in the study of radiation-induced damage to DNA and would be well suited for extension to the study of more complicated biological systems.

Organic semiconductors have gained a lot of interest due to their ease of processing, low-cost and inherent mechanical flexibility. Although most of the research has been on their electronic and optical properties, knowledge of the thermal properties is important in the design of electronic devices as well. Our group has used ac-calorimetric techniques to measure both in-plane and transverse thermal conductivities of a variety of organic semiconductors including small-molecule crystals and polymer blends. For layered crystals composed of molecules with planar backbones and silylethynyl (or germylethynyl) sidegroups projecting between the layers, very high interplanar thermal conductivities have been observed, presumably implying that heat flows between layers mostly via interactions between librations on these sidegoups. Since most organic semiconducting devices require materials in thin film rather than bulk crystal form, I have focused on using the “3ω- technique” to measure the thermal resistances of thin films of this class of organic semiconductors, including bis(triisopropylsilylethynyl) pentacene (TIPS-pn), bis(triethylsilylethynyl) anthradithiophene (TES-ADT), and difluoro bis(triethylsilylethynyl) anthradithiophene (diF-TES-ADT). For each material, several films of different thicknesses have been measured to separate the effects of intrinsic thermal conductivity from interface thermal resistance. For sublimed films of TIPS-pn and diF-TES-ADT, with thicknesses ranging from less than 100 nm to greater than 4 μm, the thermal conductivities are similar to those of polymers and over an order of magnitude smaller than those of single crystals, presumably reflecting the large reduction in phonon mean-free path due to disorder in the films. On the other hand, the thermal resistances of thin (≤ 205 nm) crystalline films of TES-ADT, prepared by vapor-annealing of spin-cast films, are dominated by their interface resistances, possibly due to dewetting of the film from the substrate during the annealing process.

The Standard Model of Particle Physics has been verified to unprecedented precision in the last few decades. However there are still phenomena in nature which cannot be explained, and as such new theories will be required. Since terrestrial experiments are limited in both the energy and precision that can be probed, new methods are required to search for signs of physics beyond the Standard Model. In this dissertation, I demonstrate how these theories can be probed by searching for remnants of their effects in the early Universe. In particular I focus on three possible extensions of the Standard Model: the addition of massive neutral particles as dark matter, the addition of charged massive particles, and the existence of higher dimensions. For each new model, I review the existing experimental bounds and the potential for discovering new physics in the next generation of experiments. For dark matter, I introduce six simple models which I have developed, and which involve a minimum amount of new physics, as well as reviewing one existing model of dark matter. For each model I calculate the latest constraints from astrophysics experiments, nuclear recoil experiments, and collider experiments. I also provide motivations for studying sub-GeV mass dark matter, and propose the possibility of searching for light WIMPs in the decay of B-mesons and other heavy particles. For charged massive relics, I introduce and review the recently proposed model of catalyzed Big Bang nucleosynthesis. In particular I review the production of Li6 by this mechanism, and calculate the abundance of Li7 after destruction of Be7 by charged relics. The result is that for certain natural relics CBBN is capable of removing tensions between the predicted and observed Li6 and Li7 abundances which are present in the standard model of BBN. For extra dimensions, I review the constraints on the ADD model from both astrophysics and collider experiments. I then calculate the constraints on this model from Big Bang nucleosynthesis in the early Universe. I also calculate the bounds on this model from Kaluza-Klein gravitons trapped in the galaxy which decay to electron-positron pairs, using the measured 511 keV gamma-ray flux. For each example of new physics, I find that remnants of the early Universe provide constraints on the models which are complimentary to the existing constraints from colliders and other terrestrial experiments.