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THE 2016 CHBGS/PROQUEST DISTINGUISHED DISSERTATION AWARD WINNERs:

Jeremy C. Ferrell, North Carolina A&T State University

A Distributed Model of Oilseed Biorefining, via Intergrated Industrial Ecology Exchanges

As the demand for direct petroleum substitutes increases, biorefineries are poised to become centers for conversion of biomass into fuels, energy, and biomaterials.  A distributed model offers reduced transportation, tailored process technology to available feedstock, and increased local resilience. Oilseeds are capable of producing a wide variety of useful products additive to food, feed, and fuel needs. Biodiesel manufacturing technology lends itself to smaller-scale distributed facilities able to process diverse feedstocks and meet demand of critical diesel fuel for basic municipal services, safety, sanitation, infrastructure repair, and food production. Integrating biodiesel refining facilities as tenants of eco-industrial parks presents a novel approach for synergistic energy and material exchanges whereby environmental and economic metrics can be significantly improved upon compared to stand alone models. This research is based on the Catawba County NC EcoComplex and the oilseed crushing and biodiesel processing facilities (capacity-433 tons biodiesel per year) located within. Technical and environmental analyses of the biorefinery components as well as agronomic and economic models are presented. The life cycle assessment for the two optimal biodiesel feedstocks, soybeans and used cooking oil, resulted in fossil energy ratios of 7.19 and 12.1 with carbon intensity values of 12.51 gC02-eq/MJ and 7.93 gC02-eq/MJ, respectively within the industrial ecology system. Economic modeling resulted in a biodiesel conversion cost of $1.43 per liter of fuel produced with used cooking oil, requiring a subsidy of $0.58 per liter to reach the break­ even point. As subsidies continue significant fluctuation, metrics other than operating costs are required to justify small-scale biofuel projects.

 

 

Hector Malagon, University of Maryland Eastern Shore

Population Dynamics of Young of the Year Summer Flounder (Paralichthys Dentatus) in Maryland Costal Bays

 

The survival, growth, and distribution of juvenile fishes in estuaries depend on the quality and quantity of their habitats. Estimating fish population parameters such as recruitment, growth and mortality rates is important for fisheries and aquatic ecosystem management. The purpose of this thesis was to investigate the spatial and temporal patterns in the abundance of Young-of-the-Year (YoY) summer flounder in the Maryland Coastal Bays and to estimate recruitment, growth and mortality rates of YoY summer flounder in the Bays.
Using two decades of trawl survey data collected by the Maryland Department of Natural Resources at 20 sampling sites in the Bays, the spatial and temporal patterns in abundance of YoY summer flounder were described for the first time. Young-of-the year summer flounder distribution and abundance were related to salinity and turbidity levels such that high concentrations occurred in areas close to rivers and creeks in early stages of development, with a shift in distribution occurring to areas close to the Ocean City inlet and eastern shore of the bays in the late stages of development during late summer and fall. Population parameters such as growth, recruitment and mortality rate were neither explained by variations in abiotic factors examined within the Bays nor by indices of large scale variation in climatic factors such as North Atlantic Oscillation (NAO) and El Niño Southern Oscillation (ENSO). Growth and mortality rates of YoY summer flounder were density-dependent in some bays, such that YoY fish attained smaller mean size at the end of summer during high recruitment than during relatively low recruitment. In contrast, mortality rate was higher at lower levels of recruitment. This dispensatory mortality perhaps contributes to the inter-annual variability in the abundance of the population
The survival, growth, and distribution of juvenile fishes in estuaries depend on the quality and quantity of their habitats. Estimating fish population parameters such as recruitment, growth and mortality rates is important for fisheries and aquatic ecosystem management. The purpose of this thesis was to investigate the spatial and temporal patterns in the abundance of Young-of-the-Year (YoY) summer flounder in the Maryland Coastal Bays and to estimate recruitment, growth and mortality rates of YoY summer flounder in the Bays.Using two decades of trawl survey data collected by the Maryland Department of Natural Resources at 20 sampling sites in the Bays, the spatial and temporal patterns in abundance of YoY summer flounder were described for the first time. Young-of-the year summer flounder distribution and abundance were related to salinity and turbidity levels such that high concentrations occurred in areas close to rivers and creeks in early stages of development, with a shift in distribution occurring to areas close to the Ocean City inlet and eastern shore of the bays in the late stages of development during late summer and fall. Population parameters such as growth, recruitment and mortality rate were neither explained by variations in abiotic factors examined within the Bays nor by indices of large scale variation in climatic factors such as North Atlantic Oscillation (NAO) and El Niño Southern Oscillation (ENSO). Growth and mortality rates of YoY summer flounder were density-dependent in some bays, such that YoY fish attained smaller mean size at the end of summer during high recruitment than during relatively low recruitment. In contrast, mortality rate was higher at lower levels of recruitment. This dispensatory mortality perhaps contributes to the inter-annual variability in the abundance of the population