The Comparison of Climate Change Rates in Rural versus Urban Areas in Tennessee An analysis of climate data was performed in three counties in Tennessee. The goal of this study is to identify the different rates of climate change in counties of varying urbanization levels. Davidson County, which contains the city of Nashville, is used as the most urban county. Two counties outside Nashville, Sumner and Dickson Counties, are used as a moderately urban county and a rural county, respectively. The level of urbanization was adopted from Tennessee Advisory Commission on Intergovernmental Relations' Index of Relative Rurality. Yearly average temperature and daily mean temperature for the warm season (May through October) were collected on each county from the years of 1960-2020 via the PRISM Climate Group at Oregon State University. A Mann-Kendall (MK) trend test was used for each individual county’s data to determine if the series had a monotonic upward trend, meaning overall temperature increase. The hypothesis of this analysis is that the most urban county will have the highest rate of warming due to the urban heat island (UHI) effect. The analysis of the yearly average temperature data for the three counties showed that Davidson and Sumner had higher Sen’s slopes and Kendall’s Taus, which were the prominent factors examined to determine the extent of climate change. Comparatively, Dickson County was found to have a lower Sen’s slope and Kendall’s Tau, which implies a lower overall rate of warming. Significance was found within all the results, since P-values were α Laina Caywood: Environmental Health, East Tennessee State University. Ying Li: Environmental Health, East Tennessee State University. Andrew Joyner: Department of Geosciences, East Tennessee State University.

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Evidence has shown that changes in land-use can affect the potential of the soil to act as a methane sink. The Lakenheath site consists of drained fenland peat, which is being re-converted to wetland. At the time of this study the site consisted of four land-use types, an intensively cultivated plot, unmanaged grassland, woodland, and wetland. Peat cores were taken from the four plots and compared for their ability to act as a methane sink. CH4 uptake was measured throughout the depth profiles using gas chromatography. Clear differences in methane oxidation rates were recorded with depth and land-use. The woodland soil showed the highest capacity for atmospheric methane oxidation, and the wetland soil was only profile that had a distinct peak of methane oxidation activity (just above the water table). Despite the change in land-use, all four soils had the capacity to oxidise both high and low concentrations of methane and so acted as a methane sink. The only exception to this was the wetland soil after persistent rainfall. The uppermost layers were water saturated and all soil sections failed to oxidise methane. Methanotroph diversity in the four soils was compared using molecular biological and enrichment techniques. Total DNA was extracted from depth profiles of the four soils and PCR amplified with 16S rRNA methanotroph group-specific primers and primers specific to subunits of the pMMO and AMO (pmoA and amoA), sMMO (mmoX) and MDH (methanol dehydrogenase, mxaF). In addition, DNA was extracted from the top 5 cm of the cultivated (drained) and flooded soil and PCR amplified with primers specific to subunits of the pMMO and AMO. These PCR products were cloned and gene libraries constructed for each soil. No significant differences were observed in retrieved methanotroph sequences from these two soils, suggesting that the methanotroph population had not altered after flooding. The sequences obtained in the molecular study were predominantly amoA sequences from nitrifiers and pmoA sequences from type II methanotrophs. No type I pmoA sequences were retrieved. Type I methanotrophs, however, were isolated directly from the peat soil in the enrichment study.

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Agriculture and Agri-Food Canada (AAFC), the Ontario Greenhouse Vegetable Growers Association (OGVG), and Queen’s University’s Solar Calorimetry Laboratory (SCL) are undertaking a joint project to evaluate the energy and crop-yield benefits of operating commercial greenhouses in isolation from the outdoor environment, i.e., eliminating natural or forced ventilation to the exterior. Implementing such a scheme requires “closing” the greenhouse envelope and the installation of an active air-conditioning system to control temperature and moisture levels that could be harmful to crop growth. To this end, a prototype air-conditioning system, centered around a liquid desiccant dehumidifier, was designed, constructed and instrumented such that its thermal and functional performance could be evaluated over extended periods. The prototype unit was installed in a “research” greenhouse located at the Agriculture Canada, Greenhouse and Processing Crops Research Center (GPCRC) located in Harrow, Ontario. Both the novel air-conditioning and monitoring systems were implemented during the course of the thesis and operated for two preliminary crop trials to characterize system performance and identify aspects needing further refinement. Data obtained over these two initial periods, indicated that, the latent and sensible cooling capacity of the novel desiccant system averaged: 2.25 kW and -0.25 kW, respectively, during the severe summer trial; and 1.25 kW and -0.1 kW, respectively, during the milder spring trial. Values obtained from the preliminary monitored data also indicate that the liquid desiccant unit operated at electrical and thermal coefficients of performance (COPs) between 0.74 and 3.1 and between 0.15 and 0.52, respectively. Finally, using the monitored data, a simple regression-based empirical model was formulated to describe the average performance of the liquid desiccant unit. This was attempted to illustrate how performance results could be generalized to assist in the future design of similar commercial-scale systems. The results of this part of the thesis indicated, however, that further test data is required to confidently characterize the unit’s performance. As well, it was concluded that addition instrumentation (specifically, the addition of a meter to measure the flowrate of the regenerator air-stream) would enhance the potential to develop a practical performance correlation. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2013-11-01 14:12:54.326