Disinfection byproducts (DBPs), such as organic chloramines, THMs, HAAs, and nitrosamines, are formed during mandatory disinfection processes in drinking water treatment. Many of these DBPs have been shown to be potentially carcinogenic. Extensive research has been conducted on the occurrence and formation of these DBPs. However, there has been limited research on their relationships with each other, which may be important for the understanding of their formation mechanisms, and the nature of their precursors is still relatively unknown. Ultimately, this information will be key for the development of possible improvements in treatment technologies. Results of this study improve the understanding of DBP formation in swimming pool water. Some BFAs and PCP additives were identified as potential DBP precursors. Influence of BFAs and PCP additives on DBP formation in swimming pool water was also illustrated. Results provided feasible strategies to minimize DBP formation while maintaining the efficiency of disinfection.

Disinfection byproducts (DBPs), such as organic chloramines, THMs, HAAs, and nitrosamines, are formed during mandatory disinfection processes in drinking water treatment. Many of these DBPs have been shown to be potentially carcinogenic. Extensive research has been conducted on the occurrence and formation of these DBPs. However, there has been limited research on their relationships with each other, which may be important for the understanding of their formation mechanisms, and the nature of their precursors is still relatively unknown. Ultimately, this information will be key for the development of possible improvements in treatment technologies. Results of this study improve the understanding of DBP formation in swimming pool water. Some BFAs and PCP additives were identified as potential DBP precursors. Influence of BFAs and PCP additives on DBP formation in swimming pool water was also illustrated. Results provided feasible strategies to minimize DBP formation while maintaining the efficiency of disinfection.

The CWB has the stated objective of increasing producer returns through maximizing sales revenue and minimizing operating costs. To maximize producer returns the CWB derives value from single-desk selling, price pooling and the initial price guarantee.<p> The initial price allows the CWB to offer a price floor to producers which is guaranteed by the Federal government. This guarantee has come under review in recent World Trade Organization (WTO) negotiations with opponents stating that the Federal government is unfairly subsidizing producers. Therefore developing methods to hedge the initial payment and remove the CWB dependency on the Federal government guarantee has taken on considerable importance.<p> Hedging the initial price has two components, the first is commodity risk, and the second is currency risk. Commodity risk basically consists of the risk that wheat prices decrease significantly from the announcement of the initial payment resulting in a wheat pool account deficit. Currency risk relates to the risk of the Canadian dollar (CAD) increasing vis-à-vis the United States dollar (USD) resulting in lower wheat prices. This is due to the fact most sales are made in USD, necessitating the conversion of USD for CAD in order to pay Canadian producers. Given recent increases in exchange rate volatility this later risk is important. <p> The goal of this study is to evaluate the currency risk present in the initial payment and to examine alternate means of mitigating this risk. A number of call option strategies will be evaluated to determine its ability to reduce the probability of a wheat pool account deficit by offsetting the effect of a rising CAD.<p> The policy variables analyzed in the thesis are the initial payment as a percentage of the Pool Return Outlook for wheat and the strike price of the call options purchased. Therefore the study will examine the effect of inputting varying initial payment levels and different strike prices for the call options in the model. This will allow for quantifiable insight into cost versus risk reduction comparisons. These comparisons will be useful in determining the most efficient mode of action for the CWB.

The accurate prediction of warm-season convective systems, and the heavy rainfall and severe weather associated with them, remains a challenge for numerical weather prediction models. This study looks at one such circumstance in which back-building convection forms perpendicular to, and above the cold pool region behind strong bow echoes. We refer to this phenomenon as a "bow and arrow" because, on radar imagery, the two convective lines resemble an archer's bow and arrow. The "arrow" can extend over hundreds of kilometers and can cause damage from high winds, hail and flooding. Events of this nature pose a particular challenge to forecast because they require an accurate forecast of the earlier convection and the effects of that convection on the environment. In this study, radar and surface observations of four events are presented to identify common environmental conditions prior to the development of the back-building convection. Additionally, simulations of three cases using the Weather Research and Forecasting (WRF) model are analyzed in an attempt to understand the mechanisms responsible for initiating and maintaining the convective line. Due to coarse resolution, observational analyses are only useful for inspection of the synoptic-scale. Model output from numerical simulations is utilized to examine the mesoscale in the vicinity of the convective arrow. Several environmental characteristics are evident in each of the studied cases. Strong southwesterly flow (inducing warm air advection and gradual isentropic lifting), in addition to directional and speed convergence into the convective arrow region possibly contribute to convection initiation. Horizontal wind speed shear and increased wind speed in the area surrounding the arrow may be associated with the linear orientation of the arrow. It seems as though when these ingredients are combined with thermodynamic instability, there is a greater possibility of formation and maintenance of a convective arrow behind a bow echo.

This dissertation focuses on the spatial aspects of oil and natural gas production to investigate the extent and effects of inefficient and unnecessary spatial competition. Because oil and natural gas are migratory, operators can cause hydrocarbon resources to flow from a neighboring property onto his or her own through rapid extraction. This problem is compounded when productive leases are comparatively small, as is the case in Texas. Following an introduction and literature review, the third chapter takes advantage of a natural experiment to demonstrate how spillovers in production limit total cumulative recovery, and how the assignment of secure property rights can enhance economic outcomes. The chapter examines production from wells in Oklahoma and Texas near the panhandle border. While wells on either side of this line have similar geologies and so should be similarly productive they are exposed to different treatments: Oklahoma has a much higher rate of unitization (a contractual scheme where competing owners hire a common operator and share profits), whereas the unitization rate in Texas is lower. Using regression discontinuity design, I find that Oklahoma wells are produced more slowly early on, and that this results in greater cumulative recovery over the course of a well’s life (150% more relative to Texas). These results are robust after controlling for reservoir specific effects, and across parametric, semi-parametric and nonparametric specifications. xiiThe fourth chapter quantifies the degree to which competing owners interfere with each other’s production through spatial spillovers. I use a spatial econometric model that controls for spatial autocorrelation and spatial dependence and can therefore identify the spillovers in production. Additionally, by comparing leases owned by competing producers to leases owned by a common producer, I show empirically how securing property rights through common ownership can alleviate the externality in production. A priori, one would expect that when a common producer owns adjacent leases, the producer has the incentive to fully account for how spillovers in production affect neighboring wells. Conversely, when adjacent landowners are in competition to extract the resource, they will not account for the damage rapid production causes at neighboring wells. After controlling for secondary injection I find that this is indeed the case for Slaughter field of West Texas. The fifth chapter investigates the statistical properties of oil and natural gas production. I find striking evidence that both oil and natural gas production are power-law distributed with the exponent approximately equal to one. This distribution might arise from disequilibrium in production and exploration. Highlighting this distribution is important because it has potential consequences for the political economy of regulation as well as for resource management. For example, because the most productive wells lie in the far-right tail of the distribution, regulation geared to prevent a Deepwater Horizon scale spill need fall on a vanishingly small percent of wells. The distribution also has consequences for management because a company profitability depends disproportionately on how it manages its most productive wells. The sixth chapter provides a short conclusion.

Headwater streams provide diverse habitat for aquatic organisms, drinking water for downstream communities and abundant recreational activities. The addition of in-stream wood to headwater channels can influence the hydrology, morphology and ecology of the system. The recruitment of wood to the channel and the export mechanisms determine the wood load and structure types formed in-stream, thus altering the channel’s morphological response. This research examined the effects of in stream wood on channel morphology in two headwater streams along the eastern slopes of the Canadian Rocky Mountains; Lyons East (LE) and Corolla Creek (CC). Lyons East has natural and anthropogenic disturbance (burned and salvage-logged) in the watershed, while Corolla Creek has anthropogenic (grazing and recreation) disturbances in the watershed. An assessment of the longitudinal spatial distribution and a reach-scale geomorphic classification were conducted to investigate the impacts of in-stream wood on channel morphology, pool formation and sediment storage. The spatial distribution of in-stream wood was 1.49 sites/100m for both watersheds, results that are comparable to previously conducted studies in similar geographic watersheds. The types of structures found in both watersheds were predominately jam formations (LE - 43%, CC - 47%), which is consistent with the wood loading and spatial distribution conceptual model previously developed by Whol and Jaeger (2009) for in-stream wood accumulations in mountain streams. At the reach-scale level of analysis, in-stream wood was found to impact channel morphology and pool forming processes. The addition of wood to the stream caused half of the studied reaches to have forced pool-riffle morphology. For all six selected study reaches, there was a decrease in expected pool spacing and an increase in the diversity of pool types. The relationship between wood-affected pools and sediment storage was examined and the results show that more sediment was stored in the burned/salvage logged reaches. Cohesive sediment was stored only in pools influenced by wood structures for half of the studied reaches. V* was generally higher in wood-affected pools for five of the six study reaches. The weighted average (V*w), which provides information regarding the storage of cohesive at the reach scale, was greater in Lyons East than in Corolla Creek. The presence of both exposed bedrock in the channel as well as the amount of vegetation are possible reasons for the smaller amounts of sediment observed in Corolla Creek. The observations from this reach scale investigation led to the development of a conceptual model, which can be used to predict the location of cohesive sediment storage in headwater streams of the Oldman River Basin. This model highlights the relationship between simultaneous recruitment of in-stream wood and sediment from local sources as a mechanism for protecting and storing cohesive sediment deposits. This research examined channel responses to in-stream wood within the context of land-use planning and Alberta’s Water for Life Strategy. There was evidence of lateral channel migration in the floodplain of both watersheds. At some sites, the channel shifted up to 30 metres while in other sections of the watershed, the channel was confined within a narrow valley. Accordingly, it is recommended that the current salvage logging guidelines be changed to include a flexible riparian buffer that would more appropriately reflect the diversity in riparian widths throughout the watersheds. In addition the best management practice is to allow natural in-stream wood processes to evolve and not to remove in-stream wood from the channel. The in-stream wood provides diverse aquatic habitat and the cycle of wood being recruited and being in the stream is part of the natural ecosystem in forested environments.

The CWB has the stated objective of increasing producer returns through maximizing sales revenue and minimizing operating costs. To maximize producer returns the CWB derives value from single-desk selling, price pooling and the initial price guarantee.<p> The initial price allows the CWB to offer a price floor to producers which is guaranteed by the Federal government. This guarantee has come under review in recent World Trade Organization (WTO) negotiations with opponents stating that the Federal government is unfairly subsidizing producers. Therefore developing methods to hedge the initial payment and remove the CWB dependency on the Federal government guarantee has taken on considerable importance.<p> Hedging the initial price has two components, the first is commodity risk, and the second is currency risk. Commodity risk basically consists of the risk that wheat prices decrease significantly from the announcement of the initial payment resulting in a wheat pool account deficit. Currency risk relates to the risk of the Canadian dollar (CAD) increasing vis-à-vis the United States dollar (USD) resulting in lower wheat prices. This is due to the fact most sales are made in USD, necessitating the conversion of USD for CAD in order to pay Canadian producers. Given recent increases in exchange rate volatility this later risk is important. <p> The goal of this study is to evaluate the currency risk present in the initial payment and to examine alternate means of mitigating this risk. A number of call option strategies will be evaluated to determine its ability to reduce the probability of a wheat pool account deficit by offsetting the effect of a rising CAD.<p> The policy variables analyzed in the thesis are the initial payment as a percentage of the Pool Return Outlook for wheat and the strike price of the call options purchased. Therefore the study will examine the effect of inputting varying initial payment levels and different strike prices for the call options in the model. This will allow for quantifiable insight into cost versus risk reduction comparisons. These comparisons will be useful in determining the most efficient mode of action for the CWB.

An acoustic field is used to increase the critical heat flux of a copper boiling heat transfer surface. The increase is a result of the acoustic effects on the vapor bubbles. Experiments are being performed to explore the effects of an acoustic field on vapor bubbles in the vicinity of a rigid heated wall. Work includes the construction of a novel heater used to produce a single vapor bubble of a prescribed size and at a prescribed location on a flat boiling surface for better study of an individual vapor bubble s reaction to the acoustic field. Work also includes application of the results from the single bubble heater to a calibrated copper heater used for quantifying the improvements in critical heat flux.

The effect of nano-structured surfaces on pool boiling heat transfer is explored in this study. Experiments are conducted in a cubical test chamber containing fluoroinert coolant (PF5060, Manufacturer: 3M Co.) as the working fluid. Pool boiling experiments are conducted for saturation and subcooled conditions. Three different types of ordered nano-structured surfaces are fabricated using Step and flash imprint lithography on silicon substrates followed by Reactive Ion Etching (RIE) or Deep Reactive Ion Etching (DRIE). These nano-structures consist of a square array of cylindrical nanofins with a longitudinal pitch of 1 mm, transverse pitch of 0.9 mm and fixed (uniform) heights ranging from 15 nm – 650 nm for each substrate. The contact angle of de-ionized water on the substrates is measured before and after the boiling experiments. The contact-angle is observed to increase with the height of the nano-fins. Contact angle variation is also observed before and after the pool boiling experiments. The pool boiling curves for the nano-structured silicon surfaces are compared with that of atomically smooth single-crystal silicon (bare) surfaces. Data processing is performed to estimate the heat flux through the projected area (plan area) for the nano-patterned zone as well as the heat flux through the total nano-patterned area, which includes the surface area of the fins. Maximum heat flux (MHF) is enhanced by ~120 % for the nanofin surfaces compared to bare (smooth) surfaces, under saturation condition. The pool boiling heat flux data for the three nano-structured surfaces progressively overlap with each other in the vicinity of the MHF condition. Based on the experimental data several micro/nano-scale transport mechanisms responsible for heat flux enhancements are identified, which include: “microlayer” disruption or enhancement, enhancement of active nucleation site density, enlargement of cold spots and enhancement of contact angle which affects the vapor bubble departure frequency.

The effect of nano-structured surfaces on pool boiling heat transfer is explored in this study. Experiments are conducted in a cubical test chamber containing fluoroinert coolant (PF5060, Manufacturer: 3M Co.) as the working fluid. Pool boiling experiments are conducted for saturation and subcooled conditions. Three different types of ordered nano-structured surfaces are fabricated using Step and flash imprint lithography on silicon substrates followed by Reactive Ion Etching (RIE) or Deep Reactive Ion Etching (DRIE). These nano-structures consist of a square array of cylindrical nanofins with a longitudinal pitch of 1 mm, transverse pitch of 0.9 mm and fixed (uniform) heights ranging from 15 nm - 650 nm for each substrate. The contact angle of de-ionized water on the substrates is measured before and after the boiling experiments. The contact-angle is observed to increase with the height of the nano-fins. Contact angle variation is also observed before and after the pool boiling experiments. The pool boiling curves for the nano-structured silicon surfaces are compared with that of atomically smooth single-crystal silicon (bare) surfaces. Data processing is performed to estimate the heat flux through the projected area (plan area) for the nano-patterned zone as well as the heat flux through the total nano-patterned area, which includes the surface area of the fins. Maximum heat flux (MHF) is enhanced by ~120 % for the nanofin surfaces compared to bare (smooth) surfaces, under saturation condition. The pool boiling heat flux data for the three nano-structured surfaces progressively overlap with each other in the vicinity of the MHF condition. Based on the experimental data several micro/nano-scale transport mechanisms responsible for heat flux enhancements are identified, which include: "microlayer" disruption or enhancement, enhancement of active nucleation site density, enlargement of cold spots and enhancement of contact angle which affects the vapor bubble departure frequency.