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Full-Text Articles in Physical Sciences and Mathematics

Development Of Exploratory Data Analysis Methods For Chemical, Spatial And Temporal Analysis Of Surface Water Quality Data: The Ontario Provincial Water Quality Monitoring Network, Shuyang Wang Dec 2018

Development Of Exploratory Data Analysis Methods For Chemical, Spatial And Temporal Analysis Of Surface Water Quality Data: The Ontario Provincial Water Quality Monitoring Network, Shuyang Wang

Electronic Thesis and Dissertation Repository

Surface water quality (SWQ) databases have been widely compiled to provide information characterizing environmental conditions. But SWQ databases appear to be under-utilized, given the large investment in their creation. One reason is that database spatial, temporal, and compositional dimension vary through time, reflecting changing priorities through time and contrasts between different agencies, making coherent analysis challenging. This thesis explores the Ontario Provincial Water Quality Monitoring Network (PWQMN) to derive higher order hydrochemical properties, to render SWQ data in “network space” permitting catchment-wide visualization, and in undertaking temporal trend analysis.

Rivers play a critical role in the terrestrial carbon cycle, but …


Causes And Consequences Of Soil Carbon Mobilization And Lake Brownification In Northern Forested Landscapes, Óscar Esbrí Senar Nov 2018

Causes And Consequences Of Soil Carbon Mobilization And Lake Brownification In Northern Forested Landscapes, Óscar Esbrí Senar

Electronic Thesis and Dissertation Repository

Global changes are fundamentally changing terrestrial and aquatic ecosystems. Some of the highest rates of global change are in the north, where they are leading to the faster destabilization of forest soil carbon and its mobilization as dissolved organic matter and causing the brownification of lakes. This thesis investigated the causes of soil carbon destabilization and consequences of the mobilized soil carbon to lake food webs. The first finding was that global change increased carbon export from catchments. Increased temperatures and changes in hydrologic connectivity interacted with catchment topography to modulate the timing, magnitude, and fate of soil carbon export. …


The Effect Of Sub-Facet Scale Geometry On Vertical Facet Temperatures In Urban Street Canyons, Rainer V.J. Hilland Oct 2018

The Effect Of Sub-Facet Scale Geometry On Vertical Facet Temperatures In Urban Street Canyons, Rainer V.J. Hilland

Electronic Thesis and Dissertation Repository

Surface temperature plays a key role in many micro-scale urban processes. Walls comprise a significant percentage of the urban surface, yet are under-represented by many methods of thermal remote sensing and not considered in detail by micro-scale surface temperature mod- els. This thesis presents a novel method of mobile thermal observation performed in urban street canyons in London, ON that uses a thermal imager as well as a visual spectrum camera to provide dense spatial and temporal resolution of micro-scale wall temperature distributions. Images are manually classified by a series of nominal variables and the resulting data set discusses the …


Metabolomics For Biomonitoring: Evaluation, Recommendations, And Test Of Efficacy, Sarah M. Mckenzie Oct 2018

Metabolomics For Biomonitoring: Evaluation, Recommendations, And Test Of Efficacy, Sarah M. Mckenzie

Electronic Thesis and Dissertation Repository

Effective biomonitoring of aquatic environments is an integral component of ecosystem protection. The metabolome is an emerging indicator that may have the potential to serve as an ideal bioindicator due to its intrinsic capacity to detect physiological changes in organisms that could foreshadow ecosystem change. My thesis consisted of two complementary objectives. First, the metabolome was evaluated against several established criteria for an ideal bioindicator and found to have significant potential. Recommendations were also made regarding implementation of the metabolome into existing biomonitoring programs. Second, the metabolome of Hexagenia spp. was evaluated as a potential indicator for environmental effects of …


Microclimate Variability Of Select Toronto Neighbourhoods Under Hot Summertime Conditions, Timothy Wiechers Jun 2018

Microclimate Variability Of Select Toronto Neighbourhoods Under Hot Summertime Conditions, Timothy Wiechers

Electronic Thesis and Dissertation Repository

Micrometeorological variability within cities has important implications for urban air and water quality, building energy consumption, and human health and thermal comfort. However, the monitoring of microscale climate is not routinely conducted. In most instances, primary meteorological observations are made under reproducible standard conditions (typically at an airport); but these open field observations tend to be unrepresentative of the intra-urban meteorological conditions.

This thesis used an alternative approach of conducting mobile traverse measurements using vehicle-mounted sensors to characterize the microclimates of Toronto, ON under hot, summertime weather conditions. Sampling occurred along two routes and incorporated sampling 8 intra-urban neighbourhoods with …


Biobutanol Production From Cellulosic And Sugar-Based Feedstock From The Corn Plant, Reyna Gomez-Flores Apr 2018

Biobutanol Production From Cellulosic And Sugar-Based Feedstock From The Corn Plant, Reyna Gomez-Flores

Electronic Thesis and Dissertation Repository

In this thesis, biobutanol production by biological fermentation was investigated from the corn plant, integrating two approaches. The first one was to utilize corn cobs, a cellulosic-based material. The second, using a new sugar-based material, sugarcorn juice. Utilizing suitable Clostridia strains for each substrate, these approaches converged into a biorefinery concept to produce renewable biofuels in Ontario, Canada. The corn cob pretreatment was carried out by a dilute acid method resulting in temperature as the variable with most significant effect towards glucose liberation. The enzymatic hydrolysis was performed utilizing a very low concentration of an enzymatic stock solution with approximately …


Modeling Of Suspended Sediment Concentration Using Conventional And Machine Learning Approaches, In Thames River, Canada, Issam Mohamed Apr 2018

Modeling Of Suspended Sediment Concentration Using Conventional And Machine Learning Approaches, In Thames River, Canada, Issam Mohamed

Electronic Thesis and Dissertation Repository

Water resource management, planning, hydraulic design, environmental conservation, reservoir management and operation all require reliable information and data about Suspended Sediment Concentration (SSC). To predict such data, direct sampling and Sediment Rating Curves (SRC) are commonly utilized. Since direct sampling can be risky during extreme weather events and SRC cannot provide satisfactorily dependable results, engineers are trying to propose new precise fore-casting approaches. Various soft computing techniques have been applied to model different hydrological and environmental problems and have showed promising results in this regard. Although many studies have been performed to simulate the phenomena of SSC at numerous rivers …


Migratory Movements Of The True Armyworm (Mythimna Unipuncta) (Haworth): An Investigation Using Naturally Occurring Stable Hydrogen Isotopes, Kyle Doward Mar 2018

Migratory Movements Of The True Armyworm (Mythimna Unipuncta) (Haworth): An Investigation Using Naturally Occurring Stable Hydrogen Isotopes, Kyle Doward

Electronic Thesis and Dissertation Repository

A number of lepidopteran agricultural pests cannot overwinter in Canada and the annual populations each summer are the result of immigration. In most years densities are low but sporadically there are major outbreaks resulting in serious economic losses. Currently, the detection of potential epidemics is based on pheromone trap catch data in the spring, which leaves a very short window for farmers to intervene if there are high numbers of immigrants. It is accepted that immigrant moth species originate from the USA but we are unsure of whether they originate from one geographic source area every year or if it …