Digital Commons Network^™

Impacts Of Climate Warming On Nutritional Quality And Soil Bacterial Communities Of Wild Blueberries, Oluwafemi A. Alaba

Electronic Theses and Dissertations

Under anthropogenic global climate change associated with greenhouse gas emissions, the mean surface temperature of the earth has increased by approximately 1 oC since the industrial age and is projected to rise by 2.6 to 4.6 oC by 2100. Wild blueberry fields in Maine are experiencing unprecedented warming, which may affect the fruit flavor and nutritional quality, soil health and microbial community, and consequently impact yield, human nutrition, and the economic well-being of wild blueberry producers. It is therefore important to assess the impact of climate warming on fruit crop nutritional quality and soil microbial community, and test potential strategies …

Influence Of Biochar As A Soil Amendment On Soil Water Content And Wild Blueberry Physiology, Abigayl Novak

Electronic Theses and Dissertations

Maine wild (or lowbush) blueberries (Vaccinium angustifolium Ait.) continue to face challenges imposed by climate change. Reduced frequency of precipitation and increased drought conditions have negatively impacted this crop since it resides in sandy soils with limited retention of water and nutrients. The wild blueberry plants growing in water- and nutrient-poor sandy soils are likely to have poor resilience to drought, resulting in a decline in berry yield during drought years. Thus, there is an urgent need to find a drought management solution for wild blueberries. Compared with other drought management practices, such as irrigation systems, mulching, and adopting drought-resistant …

Solid Acid Catalyzed Dehydration Reactions Of Biomass-Derived Alcohols, Mackenzie Todd

Electronic Theses and Dissertations

Concerns around climate change and the use of fossil resources contributing to increasing carbon dioxide concentrations in the atmosphere has motivated transitions to use biomass resources for the production of specialty chemicals and fuels, in hopes of creating a more cyclical use of carbon. The work presented here focuses on two different aspects of catalytic upgrading of biomass-derived platform molecules using heterogeneous acid catalysts. First, we use an interdisciplinary and iterative approach to process development for producing a diesel fuel additive from pyrolysis oils of woody biomass. We use fuel property calculations to define measures of success in chemical upgrading …

Immiscible Liquid-Infused Filters For Water And Aerosol Filtration, Justin Hardcastle

Electronic Theses and Dissertations

In the purification of water and air, membrane fouling is an ongoing issue that leads to the reduction of filter efficiency over time. An increase in the frequency of current chemical and mechanical cleaning methods increases system downtime, increases overall costs, and leads to the reduction of the lifetime of the membrane. Commonly used filtration materials such as polytetrafluorethylene (PTFE) and polyvinylidene fluoride (PVDF) are porous throughout and have a textured surface that facilitates the adhesion of bacteria and other foulants. To prevent this adhesion, bioinspired liquid-coated filters are proposed as a new approach to creating filters that resist fouling. …

Soil Organic Carbon In Maine, Its Responses To Biochar Addition, And Climate Change, Xue Bai

Electronic Theses and Dissertations

Soil organic carbon (SOC), as one of the largest C pools in terrestrial ecosystems, plays a key role in governing soil ecosystem processes and climate regulation. Climate change concerns have resulted in a rapidly growing interest in understanding the potential for natural climate solutions (NCS) that include enhancing SOC sequestration and reduce net atmospheric greenhouse gas (GHG) emissions. This research focused on addressing information needs about SOC in Maine, specifically in evaluating available soil databases to accurately quantify SOC density and concentration, and study the response of selected representative Maine soils to biochar amendments under a changing climate.

Maine SOC …

Economics And Operational Decision Constraints Of Small-Diameter Tree Harvesting, Libin Thaikkattil Louis

Electronic Theses and Dissertations

Sustainably managed forests are crucial in balancing trade-off between various ecosystem functions and optimum product utilization. Improving the utilization of these renewable resources through diversified forest wood products faces various socio-economic, ecological, and cultural challenges. A major challenge faced by forest managers in the Northeastern United States is overstocked stands dominated by small-diameter trees (SDT). Major woody portion of the harvested residues is constituted by SDT and are typically of low value. Data from the national inventory indicates a high number of SDT in Northeastern forests such that the average size of all trees in the region is less than …

Reaction Kinetics Analysis Of C-O Hydrogenoloysis In Phenol And 5-Hydroxymethylfurfural, Daniela Ignacia Stuck Valenzuela

Electronic Theses and Dissertations

Converting biomass to alternative fuels has attracted significant interest in recent decades. Lignin, a principal component of biomass, is composed of phenolic monomers, which can be depolymerized using fast pyrolysis to yield a “bio-oil”. However, bio-oil is not immediately suitable as a biofuel because of its high oxygen content, and it is necessary to efficiently remove these oxygen atoms by hydrodeoxygenation (HDO). This project is focused on the elucidation of the reaction kinetics associated with carbon-oxygen hydrogenolysis in phenolic molecules, which is a significant reaction for the production of hydrocarbon fuels from biomass pyrolysis oils. The studied molecules are 5-hydroxymethylfurfural …