Physical Sciences and Mathematics Commons^™

The Effects Of Sediment Acidification And Temperature On The Immune Capacity Of The Atlantic Jackknife (Razor) Clam (Ensis Leei M. Huber, 2015), Brian Preziosi

Electronic Theses and Dissertations

Sediment acidification has been shown to negatively impact clams of economic importance such as the soft-shell clam, Mya arenaria Linnaeus, 1758, and hard clam, Mercenaria mercenaria (Linnaeus, 1758). Effects of sediment acidification on razor clams, including the Atlantic jackknife clam Ensis leei M. Huber, 2015, are unknown. E. leei has been identified as a species with potential for aquaculture operations on the New England coast. E. leei may be resilient to acidification and thus persist in acidified sediments where other clams cannot. To this end, the impact of acidified surface sediment on the internal immune capacity of adult (mean shell …

A Qualitative Representation Of Spatial Scenes In R2 With Regions And Lines, Joshua Lewis

Electronic Theses and Dissertations

Regions and lines are common geographic abstractions for geographic objects. Collections of regions, lines, and other representations of spatial objects form a spatial scene, along with their relations. For instance, the states of Maine and New Hampshire can be represented by a pair of regions and related based on their topological properties. These two states are adjacent (i.e., they meet along their shared boundary), whereas Maine and Florida are not adjacent (i.e., they are disjoint).

A detailed model for qualitatively describing spatial scenes should capture the essential properties of a configuration such that a description of the represented objects …

Theory Of Lexicographic Differentiation In The Banach Space Setting, Jaeho Choi

Electronic Theses and Dissertations

Derivative information is useful for many problems found in science and engineering that require equation solving or optimization. Driven by its utility and mathematical curiosity, researchers over the years have developed a variety of generalized derivatives. In this thesis, we will first take a look at Clarke’s generalized derivative for locally Lipschitz continuous functions between Euclidean spaces, which roughly is the smallest convex set containing all nearby derivatives of a domain point of interest. Clarke’s generalized derivative in this setting possesses a strong theoretical and numerical toolkit, which is analogous to that of the classical derivative. It includes nonsmooth versions …

Northern Conifer Forest Management: Silvicultural, Economic, And Ecological Outcomes From 65 Years Of Study, Maren Granstrom

Electronic Theses and Dissertations

While forest managers once sought primarily to produce sustainable revenue from harvests, there is now growing value placed on non-timber outcomes like wildlife habitat, climate adaptability, and carbon storage. When deciding how to manage land for the future, foresters and landowners must assess the many outcomes of forestry activities and be aware of the tradeoffs inherent to achieving different goals. Given the slow growth of trees relative to other commercial crops, it is rare to have the continuity of land ownership, researchers, and funding needed to follow a stand for a full rotation or to observe a tree from recruitment …

A Longitudinal Study Of Mammograms Utilizing The Automated Wavelet Transform Modulus Maxima Method, Brian C. Toner

Electronic Theses and Dissertations

Breast cancer is a disease which predominatly affects women. About 1 in 8 women are diagnosed with breast cancer during their lifetime. Early detection is key to increasing the survival rate of breast cancer patients since the longer the tumor goes undetected, the more deadly it can become. The modern approach for diagnosing breast cancer relies on a combination of self-breast exams and mammography to detect the formation of tumors. However, this approach only accounts for tumors which are either detectable by touch or are large enough to be observed during a screening mammogram. For some individuals, by the time …

Participatory Modeling Of Tidal Circulation On Maine Mudflats To Improve Water Quality Management Of Shellfish Areas, Gabrielle V. Hillyer

Electronic Theses and Dissertations

Over the past decade, researchers have become increasingly aware of the vital role stakeholder knowledge plays in understanding complex social and environmental problems. Incorporating stakeholder knowledge into understanding complex problems allows for greater awareness and identification of community needs and can help build partnerships to support the development of applied research. In this thesis, I demonstrate the value of stakeholder knowledge and research partnerships by focusing on the soft-shell clamming industry in Maine and how a complex collaboration between clammers, municipal officials, representatives from state agencies, researchers, and other partners relied on and build adaptive capacity to address complex water …

Getting Over The Dam: Overcoming Institutional Barriers To The Recovery Of Atlantic Salmon By Navigating The Social-Science/Policy Interface, Melissa E. Flye

Electronic Theses and Dissertations

The term governance has undergone somewhat of an evolution since its inception, originally describing the act of governing, it has come to represent a more collaborative form of governing which is distinct from hierarchical control models (Marin and Mayntz, 1991). Collaborative governance refers to the systems associated with public policy decision making and resource management which span the jurisdictional boundaries of public agencies, levels of government, and/or public and private spheres in order to pursue a public policy goal or outcome (Emerson et al., 2012). Environmental management is often considered an inherently collaborative effort, as ecological systems and species rarely …

Three-Dimensional Analytical Model Of Tidal Flow In The Damariscotta River Estuary, Me, Stephanie L. Ayres

Electronic Theses and Dissertations

Estuaries are coastal bodies of water subjected to strong tidal influence and characterized by their morphology, tidal dynamics, topography, and stratification. Tidal flow is critically important to the water circulation, nutrient influx, and sediment transport in or out of an estuary. However, tidal asymmetry enhanced by estuary shape and nonlinear processes can lead to complications in estuarine flow. Analytical models are used to systematically study tidal flow within an estuary. Previous studies have derived analytical models of varying complexity and applied them to investigate tidal and residual flow. This thesis derives a three-dimensional analytical model with a perturbation expansion of …

Modeling Response Of Water Quality To Land-Use And Climate Change In Lake Auburn, Me, Nicholas Messina

Electronic Theses and Dissertations

Lake Auburn, Maine, USA, is a historically unproductive lake that has experienced multiple algal blooms since 2011. The lake is the water supply source for a population of ~60,000. We modeled past temperature, and concentrations of dissolved oxygen (DO) and phosphorus (P) in Lake Auburn by considering the watershed and internal contributions of P as well as atmospheric factors, and predicted the change in lake water quality in response to future climate and land-use changes. A stream hydrology and P-loading model (SimplyP) was used to generate input from two major tributaries into a lake model (MyLake) to simulate physical mixing, …

Multi-Level Governance Of Climate Change Adaptation: United Nations Negotiations And Adaptation Project Implementation In Nicaragua And Samoa, Anna E. Mcginn

Electronic Theses and Dissertations

The rapid entry into force of the Paris Agreement reaffirmed, with certainty, that the international community would continue its efforts to mitigate greenhouse gas emissions and adapt to climate change impacts opening a new era of international cooperation on climate change. This thesis explores how both negotiations around climate change adaptation and adaptation project implementation have evolved in this post-Paris Agreement era (from adoption in December 2015 to present). Using the United Nations Framework Convention on Climate Change’s (UNFCCC) Adaptation Fund as the central lens, the chapters explore international negotiations around the Fund as well as two Adaptation Fund funded …

Mechanisms Of Ice Core Stable Isotope Variability In The Upper Kaskawulsh-Donjek Region, St. Elias Mountains, Yukon, Canada, Erin A. Mcconnell

Electronic Theses and Dissertations

I use instrumental and ice core records to examine drivers of observed isotope variability in the Upper Kaskawulsh-Donjek (UKD) region of the St. Elias Mountains, Yukon, Canada over the time frame of instrument-proxy overlap (mid-1900s to present). One of the drivers of post-depositional isotope signal alteration is the vertical percolation of meltwater from the glacier surface through shallow layers of snow, which causes a reduction in the amplitude of the isotope signal recorded in ice cores. I examine isotope signal preservation in two sites in the St. Elias Mountains: Eclipse Icefield and Icefield Divide. These sites are relatively close (~30 …

Microbial Diversity Of The Symbiotic Colony Of Bacteria And Yeast (Scoby) And Its Impact On The Organoleptic Properties Of Kombucha, Danielle L. St-Pierre

Electronic Theses and Dissertations

Kombucha is an effervescent fermented tea beverage that is gaining popularity for its probiotic nature and purported health benefits. The market for kombucha is expected to reach $1.8 billion by the year 2020. The composition of microbes that compose the symbiotic colony of bacteria and yeast (SCOBY) is highly variable with some species commonly found from the Gluconobacter, Acetobacter, Zygosaccharomyces, Saccharomyces, and Schizosaccharomyces genera.

It was hypothesized that different SCOBYs, obtained from different sources would vary in microbial diversity and produce different biochemical and flavor profiles in the resulting beverage over several generations. Kombucha is a fermented …

Fractures, Fluids, And Metamorphism: Shear Zone Initiation In The Marcy Anorthosite Massif, Adirondacks, New York, Usa, James Hodge

Electronic Theses and Dissertations

Localized shear zones are important rheological features that influence deformation behavior throughout the Earth’s middle-to-lower crust. Therefore, the processes through which shear zones initiate and localize remains an important geologic question. The study of strain localization and shear zone initiation is made difficult due to continued deformation overprinting the microstructures which lead to initiation and obfuscating the context in which localization occurred. The Marcy anorthosite in the Adirondack Highlands, New York, is a nominally granulite-facies, plagioclase-rich massif cut by centimeter-to-meter scale shear zones which provides a natural example of shear zone localization within the middle-to-lower crust. My work focuses on …

Synthesis And Characterization Of Heteronuclear Inorganic Complexes For The Photodegradation Of Persistant Organic Pollutants, Matthew A. Moyet

Electronic Theses and Dissertations

The focus of this thesis is to investigate the structural modification and characterization potential of common photocatalysts that have various uses for environmental remediation purposes. Pollution involving organic chemicals is one of the most common scenarios found in communities throughout the country. Efforts to rid contaminated drinking water supplies of these chemicals include physical and chemical filters, which have limited ability and efficacy. This lack of efficient filtration services has led to an increased demand for more effective treatment methods. Chemical species that react in the presence of light are known as photocatalysts and have been used in previous studies …

Mountain Livelihoods In A Time Of Change: A Case Study Of Upper Mustang In Nepal, Sandesh Shrestha

Electronic Theses and Dissertations

A case study was conducted in a remote Himalayan village—Yara—in the Upper Mustang region of Nepal. The goal of this study was to understand and assess the livelihood strategies of local people in the village. The study focused on understanding the socio-economic and environmental driving factors of livelihood vulnerability, prevalent livelihood activities, emergent livelihood strategies, and resulting livelihood outcomes in the village. We used multiple data generation methods, which included both qualitative social science and quantitative biophysical components. For the qualitative component, we utilized multiple data generation methods including key informant interviews, semi-structured household interviews, group discussions, and field observations. …

A Tale Of Two Bays: The Development And Applications Of The Saco And Casco Modeling Project, Stephen M. Moore

Electronic Theses and Dissertations

This thesis details the development and application of a finite-volume, hydrodynamic model of Saco and Casco Bays. The primary study conducted herein focused on coupling storm simulations with sea level rise (SLR) to identify vulnerabilities of the two bays. The February 1978 Northeaster and an April freshwater discharge event in 2007 following the Patriot’s Day Storm were modeled by utilizing the Finite-Volume Coastal Ocean Model (FVCOM). Both events were repeatedly simulated under SLR scenarios ranging from 0 to 7 ft. Modeled storm responses were identified from the 1978 blizzard simulations and were tracked across SLR scenarios. By comparing changes in …

Improved Estimates Of Tributary Nitrogen Load To Casco Bay, Maine, Whitley J. Gray

Electronic Theses and Dissertations

Over the past two decades, total nitrogen (TN) concentrations have increased in Casco Bay (CBEP 2015). The sources of the increased nitrogen are poorly understood but occur with simultaneous population growth and land use changes. The total riverine nitrogen load to Casco Bay was previously estimated by Liebman and Milstead (2012) using the United States Geologic Survey’s (USGS) SPAtially Referenced Regression On Watershed attributes (SPARROW) model. The SPARROW model uses watershed characteristics, regional monitoring data and nitrogen source data to estimate nitrogen loading but was not validated using measurements of nitrogen in the Casco Bay watershed. This study attempts to …

Investigation Of Student Understanding Of Implicit Differentiation, Connor Chu

Electronic Theses and Dissertations

Challenges that students face in first semester calculus have been found to be a factor in high attrition rates of students from science, technology, engineering, and mathematics (STEM) majors. With an increase in the demand for STEM graduates, an attempt must be made to remedy this issue. Research has shown that students have difficulties with many topics in the realm of calculus. Of these, students have been found to struggle with the concept of derivative and ideas related to it. However, some derivative topics have not been examined as thoroughly as others. Implicit differentiation, a technique that allows us to …

An Epidemiological Model With Simultaneous Recoveries, Ariel B. Farber

Electronic Theses and Dissertations

Epidemiological models are an essential tool in understanding how infection spreads throughout a population. Exploring the effects of varying parameters provides insight into the driving forces of an outbreak. In this thesis, an SIS (susceptible-infectious-susceptible) model is built partnering simulation methods, differential equations, and transition matrices with the intent to describe how simultaneous recoveries influence the spread of a disease in a well-mixed population. Individuals in the model transition between only two states; an individual is either susceptible — able to be infected, or infectious — able to infect others. Events in this model (infections and recoveries) occur by way …

Development Of Bismuth Oxyhalide Photocatalysts For Environmental And Industrial Applications, Robert Arthur

Electronic Theses and Dissertations

Heterogeneous semiconductor photocatalysis, of interest for water splitting and environmental remediation applications, uses light to drive reactions. Metal oxide and sulfide semiconductors have been previously studied but have limitations that include large band gap energies and high rates of recombination. Bismuth oxyhalides (BiOX) are an emerging class of photocatalysts with tunable band gaps and low rates of recombination due to their unique crystal structures. Studies of BiOX photocatalytic activity have largely focused on removal of azo dyes from aqueous solutions, with little attention paid to degradation byproducts. Furthermore, these catalysts have not been explored as a means to conduct organic …

New Methodologies For Examining And Supporting Student Reasoning In Physics, John C. Speirs

Electronic Theses and Dissertations

Learning how to reason productively is an essential goal of an undergraduate education in any STEM-related discipline. Many non-physics STEM majors are required to take introductory physics as part of their undergraduate programs. While certain physics concepts and principles may be of use to these students in their future academic careers and beyond, many will not. Rather, it is often expected that the most valuable and longlasting learning outcomes from a physics course will be a repertoire of problem-solving strategies, a familiarity with mathematizing real-world situations, and the development of a strong set of qualitative inferential reasoning skills.

For more …

Optical Memory Behavior, Metallophilic Luminescence, And Chemical Sensing Ability Of Inorganic And Organometallic Complexes: Development Of Optoelectronic Materials, Aaron D. Nicholas

Electronic Theses and Dissertations

This dissertation is divided into three sections: (1) optical memory, (2) metallophilic-based luminescence, and (3) chemical sensors. (1) Optical memory behavior of d¹⁰metal Cu(I) thiocyanate salts are investigated to explore their potential use in the development of digital data storage devices. From this study we have discovered a new class of CuSCN(3-BrPy)₂optical memory material which undergo a reduction in emission intensity upon laser irradiation. This loss of emission intensity can be reversed simply by heating the sample to room temperature. The mechanism by which this emission loss occurs has been studied, revealing a migrating Br atom …

Paper Structure Formation Simulation, Tyler R. Seekins

Electronic Theses and Dissertations

On the surface, paper appears simple, but closer inspection yields a rich collection of chaotic dynamics and random variables. Predictive simulation of paper product properties is desirable for screening candidate experiments and optimizing recipes but existing models are inadequate for practical use. We present a novel structure simulation and generation system designed to narrow the gap between mathematical model and practical prediction. Realistic inputs to the system are preserved as randomly distributed variables. Rapid fiber placement (~1 second/fiber) is achieved with probabilistic approximation of chaotic fluid dynamics and minimization of potential energy to determine flexible fiber conformations. Resulting digital packed …

Blacklegged Tick (Ixodes Scapularis) Distribution In Maine, Usa, As Related To Climate Change, White-Tailed Deer, And The Landscape, Susan P. Elias

Electronic Theses and Dissertations

Lyme disease is caused by the bacterial spirochete Borrelia burgdorferi, which is transmitted through the bite of an infected blacklegged (deer) tick (Ixodes scapularis). Geographic invasion of I. scapularis in North America has been attributed to causes including 20th century reforestation and suburbanization, burgeoning populations of the white-tailed deer (Odocoileus virginianus) which is the primary reproductive host of I. scapularis, tick-associated non-native plant invasions, and climate change. Maine, USA, is a high Lyme disease incidence state, with a history of increasing I. scapularis abundance and northward range expansion. This thesis addresses the question: “To …

Optimizing Legume-Based Nitrogen Fertility For Organic Small Grain Systems, Margaret A. Pickoff

Electronic Theses and Dissertations

In the past decade, Maine has witnessed a steady rise in consumer demand for organic small grain products, accompanied by the swift creation of new businesses that cater to this demand, including bakeries, flour mills, malt houses, and distilleries. Maine’s farmers have been slower to respond; only a small percentage of the 40,000+ acres of oats and barley being grown in the state, for example, is certified organic (National Agricultural Statistics Service, 2012). Given this combination of land resources, infrastructure, and consumer demand, Maine has the potential to become a regional leader in organic small grain production. According to our …

Using Question Variations To Access Alternate Student Thinking About The Same Physical Situations, Jeffrey Mathis Hawkins

Electronic Theses and Dissertations

Assessing students’ understanding of physics is a critical element for improving physics education. This dissertation presents and demonstrates a method to better assess student understanding of physics by varying the types of questions asked of students. The method presented herein, which is based on the Specific Difficulties and Resources frameworks, involves modifying the task students are asked to complete when analyzing the physics of a particular physical situation. Creating question variations that ask students to address a particular correct or incorrect outcome of the physical situation, eliminate an incorrect outcome, or justify a correct outcome provided to them can provide …

Valuing The Economic Benefits Of Conservation Lands In Downeast Maine, Lesley Lichko

Electronic Theses and Dissertations

Natural ecosystems provide numerous benefits that contribute to humans and the economy, including market goods such as timber and forest products, as well as benefits that are not directly measured in the marketplace, such as wildlife habitat provision and recreational provision. These benefits are collectively known as ecosystem services. Natural ecosystems are under significant pressure to be converted to other uses from factors such as shifts in ownership, land use change, fragmentation and climate change. To counter these effects, and to protect ecosystem services, public and private entities have worked to place land in conservation; however, conservation is often controversial …

Tide And Storm Surge Dynamics In Estuaries Of Variable Morphology, Preston Spicer

Electronic Theses and Dissertations

Storm surges are the most destructive component of coastal storms, and climate change is predicted to enhance the frequency of intense storm events in the future. Currently, most storm surge forecasting assumes linear surges and the extent to which this assumption leads to model inaccuracies is currently unknown. The goals of this research are to characterize storm surge in estuaries and determine the contribution of nonlinear tide-surge interaction to total inland surges. A citizen science experiment was conducted in four estuaries in Maine. Results show the estuary shape influences surges through convergence, friction and man-made constrictions. These mechanisms modified total …

Climate-Driven Migration: Prioritizing Cultural Resources Threatened By Secondary Impacts Of Climate Change, Frankie St. Amand

Electronic Theses and Dissertations

Archaeological sites suffer increasingly destructive primary impacts of climate-driven natural hazards, including sea level rise, flooding, and erosion. Action is generally limited to mitigation and salvage of immediately threatened sites, with little attention or forethought given to secondary effects, such as destruction of interior archaeological resources by inland migration of affected populations. The United Nations predicts a growing trend in resettlement of climate-affected communities from areas where in-situ infrastructure adaptations are not economically feasible, legal, or physically possible. While adapting existing urban infrastructure (e.g., abating combined sewage overflows) is a viable option in the primary impact zone (e.g. coastal areas …

Luminescence Antenna Behavior In Lanthanide Complexes And Luminescence Sensing In Group 11 Iodides, Francis Barnes

Electronic Theses and Dissertations

In this thesis luminescent materials are studied. The luminescent materials studied are lanthanide complexes and group 11 iodide sensing abilities. Emission intensity of the lanthanide complexes through direct excitation of the lanthanide ion are relatively weak. To overcome this, three unique organic ligands were utilized to synthesize lanthanide nitrate complexes in which higher emission intensity can be observed via the antenna effect. Increased emission intensity resulted for Eu^III and Tb^III complexes for each ligand except triphenylphosphane oxide (only the Tb^III complex demonstrated increased emission intensity). Latva’s empirical rule allows for the antenna effect to occur, in which …