Physical Sciences and Mathematics Commons^™

A Mechanistically Guided Approach To Treatment Of Multi-Wavelet Reentry: Experiments In A Computational Model Of Cardiac Propagation, Richard T. Carrick

Graduate College Dissertations and Theses

Atrial fibrillation (AF) is the most common cardiac arrhythmia in the United States today. However, treatment options remain limited despite the enormous magnitude of both AF prevalence and the associated economic cost. Of those treatment options that are available, ablation-based interventional methods have demonstrated the highest rates of long-term cure. Unfortunately, these methods have substantially lower efficacy in patients with heavier burdens of disease, thus leaving the most affected individuals with the least hope for successful treatment.

The focus of this research is to develop a mechanistically guided approach towards the treatment of multi-wavelet reentry (MWR), one of the primary …

Evaluating Stormwater Pollutant Removal Mechanisms By Bioretention In The Context Of Climate Change, Amanda Cording

Graduate College Dissertations and Theses

Stormwater runoff is one of the leading causes of water quality impairment in the U.S. Bioretention systems are ecologically engineered to treat stormwater pollution and offer exciting opportunities to provide local climate change resiliency by reducing peak runoff rates, and retaining/detaining storm volumes, yet implementation is outpacing our understanding of the underlying physical, biological, and chemical mechanisms involved in pollutant removal. Further, we do not know how performance will be affected by increases in precipitation, which are projected to occur in the northeastern U.S. as a result of climate change, or if these systems could act as a source or …

Quantifying Soil Greenhouse Gas Emissions And Soil Carbon Storage To Determine Best Management Practices In Agroecosystems, Tyler Goeschel

Graduate College Dissertations and Theses

Intensive agriculture, coupled with an increase in nitrogen fertilizer use, has contributed significantly to the elevation of atmospheric greenhouse gases (GHGs), including carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). Rising GHG emissions usually mean a decrease in soil carbon. Currently, soil C is twice that of all standing crop biomass, making it an extremely important player in the C cycle. Fortunately, agricultural management practices have the potential to reduce agricultural GHG emissions whilst increasing soil C. Management practices that impact GHG emissions and soil C include various tillage practices, different N fertilization amounts and treatments (synthetic N, cattle …

An Alternative Sensor Fusion Method For Object Orientation Using Low-Cost Mems Inertial Sensors, Joshua Lee Bouffard

Graduate College Dissertations and Theses

This thesis develops an alternative sensor fusion approach for object orientation using low-cost MEMS inertial sensors. The alternative approach focuses on the unique challenges of small UAVs. Such challenges include the vibrational induced noise onto the accelerometer and bias offset errors of the rate gyroscope. To overcome these challenges, a sensor fusion algorithm combines the measured data from the accelerometer and rate gyroscope to achieve a single output free from vibrational noise and bias offset errors.

One of the most prevalent sensor fusion algorithms used for orientation estimation is the Extended Kalman filter (EKF). The EKF filter performs the fusion …

The Structural Evolution Of A Portion Of The Median Batholith And Its Host Rock In Central Fiordland, New Zealand: Examples Of Partitioned Transpression And Structural Reactivation, Hannah Jane Blatchford

Graduate College Dissertations and Theses

This thesis presents the results of structural analyses and detailed field mapping from a region near Adams Burn in central Fiordland, New Zealand. The region preserves assemblages of metasedimentary and metaigneous rocks deposited, intruded, and ultimately metamorphosed and deformed during the growth of a Gondwana-margin continental arc from Cambrian-Early Cretaceous. Evidence of arc growth is preserved in the Late Devonian-Early Cretaceous Median Batholith, a belt of intrusive rock whose growth culminated with the emplacement of the Western Fiordland Orthogneiss (WFO) into the middle-lower crust of the margin. Following this magmatic flare-up, the margin experienced Late Cretaceous extensional orogenic collapse and …

Master's Project - Solar Farming In Vermont - What's The Harvest?, Sam Carlson

Rubenstein School Masters Project Publications

An operational research project to investigate net economic, environmental and public policy benefits from converting land from agriculture to solar electricity generation was undertaken on a 15-acre farm in Proctor, Vermont. Two solar arrays (66 KW AC and 500 KW AC) were established.

The net after-tax financial return on cash equity of the 66 KW AC solar project was calculated to be 21% for the investor over a 25-year period (less than 1% average annual rate of return), while the financial return for the 500 KW AC solar project was 145% over a similar period (5.8% average annual rate of …

High Flow Events As Hot Moments Of Reactive Fe And P Export: Impacts Of Land Cover And Seasonality, Braden Rosenberg

Graduate College Dissertations and Theses

High flow events often comprise the majority of annual discharge and riverine geochemical flux of phosphorus (P) and metals such as iron (Fe) and manganese (Mn) due to glacial melt, snowmelt, and storm-driven sustained high flow. Aquatic ecosystem productivity in receiving water bodies such as Lake Champlain and the Gulf of Alaska (GoA) are impacted by the riverine import of nutrients. The magnitude of these high flow events can be a strong predictor of receiving water body conditions, and in some cases can contribute to eutrophication. We explore the intersection of high flow events and land cover in contrasting catchments …

Long-Term Forest Carbon Storage And Structural Development As Influenced By Land-Use History And Reforestation Approach, Andrea Rose Urbano

Graduate College Dissertations and Theses

Temperate forests are an important carbon sink, yet there is uncertainty regarding land-use history effects on biomass accumulation and carbon storage potential in secondary forests. Understanding long-term biomass dynamics is important for managing forests as carbon sinks and for co-benefits such as watershed protection and biodiversity. However there are many unanswered questions regarding these dynamics in northeastern U.S. forests: How have secondary forests of the U.S. Northeast recovered post nineteenth century agricultural abandonment? How has the region's extensive land-use history influenced long-term structural development and aboveground carbon storage? To answer these questions, we employed a longitudinal study based on twelve …

Investigations Into Carbon Nanotube And Natural Product Synthesis., Geoffrey Giampa

Graduate College Dissertations and Theses

This dissertation describes research into the synthesis of carbon nanotubes using traditional organic synthetic methods, as well as work on the fragmentation of β-hydroxy-α-diazoesters with a γ-hetero group and applications of their reactivity towards natural product synthesis.

Carbon nanotubes are unique structures that can exhibit different electronic properties based on their chiral vector, and are a potential future source of semiconductors. Current methods of synthesis are unable to be adapted to commercial synthesis, providing the opportunity for the application of organic synthetic methods to generate them more uniformly and on a larger scale.

The generation of tethered aldehyde ynoates and …

Master's Project - Wildlife Habitat Linkages Surrounding The Lake George And Southern Lake Champlain Region, Sam E. Talbot

Rubenstein School Masters Project Publications

Conservation priorities – when developed systematically and objectively – can maximize land protection efforts in heterogeneous landscapes susceptible to parcelization and development. One such region surrounds Lake George and Southern Lake Champlain, nested between the Green and Adirondack Mountains. This mosaic of conserved and private parcels sits upon an array of forest, agriculture, wetland, and development valuable to both humans and resident wildlife species. This landscape’s inherent connectedness provides many benefits to wildlife, including species richness, enhanced persistence, and increased genetic interchange. However, it is difficult to make definitive statements about potential wildlife movement through such complex matrices. Therefore, wildlife …

Master's Project: Describing Forest Structure In Southern Blue Ridge Cove Forests: A Lidar-Based Analysis, Jamie Ervin

Rubenstein School Masters Project Publications

The practice of ecological restoration requires identifying a reference, or desired condition. In the Eastern United States, reference conditions can be difficult to identify due to the widespread impacts of anthropogenic influences like logging, fire suppression, and forest fragmentation on ecosystem structure. The Southern Appalachian Mountains contain some of the largest patches of unlogged primary forests in the Eastern United States. Although not entirely unaltered by humans, these existing primary forests can provide important information about the composition and structure of the Southern Appalachian landscape prior to Euro-American settlement.

Cove forests occupy mid-elevation slopes throughout the Southern Appalachians. Due to …

Master's Project - Connecting Guests To The Landscape At Kripalu: Ecological Assessment, Interpretation, And Education, Jessica D. Griffen

Rubenstein School Masters Project Publications

Sweeping views of the Berkshires and miles of trails await guests at Kripalu Center for Yoga and Health in western Massachusetts, yet surprisingly few visitors venture outside. I collaborated with Mass Audubon to transform Kripalu's grounds from a beautiful backdrop viewed through the windows to an essential part of the guest experience. To accomplish this, I conducted a rapid ecological assessment of the 125-acre property, mapped its network of trails, and piloted natural history programs for guests. The rapid ecological assessment serves as a resource for Kripalu’s grounds staff and future educators. To encourage more guests to venture outside, I …

The Role Of Green Leafy Plants In Atmospheric Chemistry: Volatile Emissions And Secondary Organic Aerosol, Rebecca Harvey

Graduate College Dissertations and Theses

Aerosols play important roles in atmospheric and environmental processes. Not only do they impact human health, they also affect visibility and climate. Despite recent advances made to under their sources and fate, there remains a limited understanding of the mechanisms that lead to the formation of aerosols and their ultimate fate in the atmosphere. These knowledge gaps provide the crux of the research reported herein, which has focused on identifying novel sources of atmospheric aerosol, characterizing its physical and optical properties, and rationalizing these properties using an in-depth knowledge of the molecular level mechanisms that led to its formation.

Upon …

Monomial Characters Of Finite Groups, John Mchugh

Graduate College Dissertations and Theses

An abundance of information regarding the structure of a finite group can be obtained by studying its irreducible characters. Of particular interest are monomial characters – those induced from a linear character of some subgroup – since Brauer has shown that any irreducible character of a group can be written as an integral linear combination of monomial characters. Our primary focus is the class of M-groups, those groups all of whose irreducible characters are monomial. A classical theorem of Taketa asserts that an M-group is necessarily solvable, and Dade proved that every solvable group can be embedded as a subgroup …

A Nanoparticle/Enzyme System For The Simultaneous Detection And Decontamination Of Organophosphates, Brendon Mark Miller

Graduate College Dissertations and Theses

The need for a direct visual response system for the detection of organophosphorus compounds stems from the continued threat and use of these toxic agents in military and terrorist conflicts. The development of an enzyme-inhibitor triggered release system allows for direct visual detection with high specificity. Mesoporous silica nanoparticles (MSNs) have physical features that make them attractive as scaffolds for the construction of these systems, such as pore diameters (20-500 Á) that can be synthetically controlled, large surface areas (300-1500 m2g-1), large pore volumes, chemical inertness, stability at elevated temperatures, and surfaces that can be easily functionalized. In our studies, …

Homology Modeling And Molecular Docking Of Antagonists To Class B G-Protein Coupled Receptor Pituitary Adenylate Cyclase Type 1 (Pac1r), Suzanne Louise Stanton

Graduate College Dissertations and Theses

Recent studies have identified the Class B g-protein coupled receptor (GPCR) pituitary adenylate cyclase activating polypeptide type 1 (PAC1R) as a key component in physiological stress management. Over-activity of neurological stress response systems due to prolonged or extreme exposure to traumatic events has led researchers to investigate PAC1R inhibition as a possible treatment for anxiety disorders such as post-traumatic stress disorder (PTSD). In 2008, Beebe and coworkers identified two such small molecule hydrazide antagonists and a general pharmacaphore for PAC1R inhibition. However, a relative dearth of information about Class B GPCRs in general, and PAC1R in specific, has significantly hindered …

Evolving Spatially Aggregated Features For Regional Modeling And Its Application To Satellite Imagery, Sam Kriegman

Graduate College Dissertations and Theses

Satellite imagery and remote sensing provide explanatory variables at relatively high resolutions for modeling geospatial phenomena, yet regional summaries are often desirable for analysis and actionable insight. In this paper, we propose a novel method of inducing spatial aggregations as a component of the statistical learning process, yielding regional model features whose construction is driven by model prediction performance rather than prior assumptions. Our results demonstrate that Genetic Programming is particularly well suited to this type of feature construction because it can automatically synthesize appropriate aggregations, as well as better incorporate them into predictive models compared to other regression methods …

Patterns Of Asthma Exacerbation Related To Climate And Weather In The Northeast Kingdom Of Vermont, Quincy Mckenzie Campbell

Graduate College Dissertations and Theses

Asthma is a chronic respiratory disease characterized by long- and short-term inflammation and bronchospasm susceptible to multiple triggers that affects patients across the lifespan. Asthma management is a primary care priority in Vermont, where there continues to be an above-average prevalence of asthma among both children and adults as compared to other states. However, many of Vermont's children and especially adults with asthma are not participating in regular check-ups for asthma management that would best prevent exacerbation of asthma symptoms. Several climate and weather elements including, but not limited to, extreme temperatures and particulate matter are known asthma triggers. Vermont's …

Integrating Management For Old-Growth Characteristics With Enhanced Carbon Storage Of Northern Hardwood-Conifer Forests, Sarah Eliot Ford

Graduate College Dissertations and Theses

Forest management practices emphasizing stand structural complexity are of interest across the northern forest region of the United States because of their potential to enhance carbon storage. Our research is nested within a long-term study evaluating how silvicultural treatments promoting late-successional forest characteristics affect aboveground biomass development in northern hardwood forests. We are testing the hypothesis that biomass development (carbon storage) will be greater in structural complexity enhancement (SCE) treatments when compared to conventional uneven-aged treatments. SCE treatments were compared against selection systems (single-tree and group) modified to retain elevated structure. Manipulations and controls were replicated across 2-hectare treatment units …

Placing Natural Resource Decisions In Social And Historical Contexts: Sociological Inquiries Into Agency Communications, Management Rationalities, And Community Change, Emilian Geczi

Graduate College Dissertations and Theses

A sociological understanding of natural resource management decisions traces the links between historical change (How does this historical period differ from other periods?), society (What social relations exist at this time and how do they persist or change?), and individuals (What types of conduct and discourse prevail in this society and in this period?). The papers submitted for this dissertation examine the connections between identity, social milieu, and historical change relative to three resource management issues:

(1) The promotion of nature play areas as a novel landscape form. Analysis of agency materials suggests that these spaces are advertised as bucolic …

Invasive Plant Ecology In Vermont: Insights From Spatial Analysis And Interactions Of Garlic Mustard (Alliaria Petiolata) With Native Plants And Invertebrates, Chenin Kathleen Limback

Graduate College Dissertations and Theses

Causes and patterns of invasive plant species establishment and success depend broadly upon their ecology, including habitat suitability and interactions with other plants and animals. Here I examine the traits and distribution of invasive plants in Vermont, using spatial analysis, laboratory and field studies. I used GIS to investigate environmental factors correlated with presence of 19 invasive plant species in Vermont campgrounds. My results support the assumption that human dispersal of invasive plant seed and stock may be more important than natural dispersal of these plant species to new sites. I also investigate in-depth the relationships of invasive herbaceous garlic …

Earthworms In Vermont Forest Soils: A Study Of Nutrient, Carbon, Nitrogen And Native Plant Responses, Ryan Melnichuk

Graduate College Dissertations and Theses

Anthropogenic activities surrounding horticulture, agriculture and recreation have increased dispersal of invasive earthworms. The introduction of earthworms initiates many physical and chemical alterations in forest soils previously unoccupied by earthworms. Three trials were performed to assess the effects of earthworms on soil-water dynamics, C and N and defensive/storage compound production by a native plant.

The first trial was a greenhouse experiment, performed to assess the impact of two ecologically contrasting invasive earthworm species on percolate and evaporative soil water loss. Mesocosms were constructed to simulate a typical forest Entisol commonly penetrated by the species of interest, Lumbricus terrestris and Amynthas …

Establishing Chemical Mechanisms And Estimating Phase State Of Secondary Organic Aerosol From Atmospherically Relevant Organic Precursors, Shashank Jain

Graduate College Dissertations and Theses

Organic aerosol (OA) is a ubiquitous component of atmospheric particulate that influences both human health and global climate. A large fraction of OA is secondary in nature (SOA), being produced by oxidation of volatile organic compounds (VOCs) emitted by biogenic and anthropogenic sources. Despite the integral role of SOA in atmospheric processes, there remains a limited scientific understanding of the chemical and physical changes induced in SOA as it ages in the atmosphere. This thesis describes work done to increase the knowledge of processes and properties of atmospherically relevant SOA.

In the work presented in this thesis, I have worked …

Uncommon Numerical Instability In The Method Of Characteristic Applied To Hyperbolic Equations, Zihao Deng

Graduate College Dissertations and Theses

This thesis presents the stability analysis of the numerical method of characteristic (MoC) that is applied to hyperbolic partial differential equations (PDEs). Simple Euler method, Modified Euler method and Leapfrog method are used for numerical integration along the characteristics. The corresponding MoC schemes are referred to as MoC-SE, MoC-ME, and MoC-LF respectively.

We discovered and explained two unusual phenomena. First, certain non-periodic boundary condition (b.c.) could eliminate the numerical instability for some schemes such as the MoC-ME, where the instability exists for periodic b.c. However, it is commonly believed that

if von Neumann analysis, i.e., assuming periodic b.c., predicts numerical …

Impacts Of Forest Disturbance On Small Mammal Distribution, Allyson Lenora Degrassi

Graduate College Dissertations and Theses

Natural habitat in the eastern United States has diminished over the past century because of the effects of invasive species. Both plant and animal invaders can alter habitat structure and may decrease survival of native species. The degree to which an invasive species alters ecosystem function depends on the functional characteristics of affected species and the resulting cascading effects. The loss of important native species, such as foundation species, can potentially influence the structure and distribution of animal communities because of the foundation species' unique ecosystem roles. The foundation species concept is relatively new to the terrestrial ecology and the …

Investigating The Influence Of Gold Nanoparticles On The Photocatalytic And Catalytic Reactivity Of Porous Tungsten Oxide Microparticles, Daniel P. Depuccio

Graduate College Dissertations and Theses

Tungsten oxide (WO3) is a semiconducting transition metal oxide with interesting electronic, structural, and chemical properties that have been exploited in applications including catalysis, gas sensing, electrochromic displays, and solar energy conversion. Nanocrystalline WO3 can absorb visible light to catalyze heterogeneous photooxidation reactions. Also, the acidity of the WO3 surface makes this oxide a good thermal catalyst in the dehydration of alcohols to various industrially relevant chemicals. This dissertation explores the photocatalytic and thermal catalytic reactivity of nanocrystalline porous WO3 microparticles. Furthermore, investigations into the changes in WO3 reactivity are carried out after modifying the porous WO3 particles with gold …

A Study Of The Physicochemical Properties Of Dense And Mesoporous Silica Nanoparticles That Impact Protein Adsorption From Biological Fluids, Alden Michael Clemments

Graduate College Dissertations and Theses

At the intersection of materials chemistry and biology, biomaterials have been successfully employed in an array of medical applications. From diagnostic tools to targeted drug delivery, the modular physical and chemical properties of these materials provide numerous applications. For example, porous nanoparticles have been widely integrated as vehicles to carry chemotherapeutics to localized tumor sites. By encapsulating these cytotoxic compounds within a porous framework, the commonly associated adverse side effects of conventional chemotherapeutics, such as Doxorubicin, have been greatly reduced. One such material, mesoporous silica, has received widespread attention due to its excellent biocompatibility, high surface area to mass ratio, …

The Impacts Of Climate Change On Precipitation And Hydrology In The Northeastern United States, Justin Guilbert

Graduate College Dissertations and Theses

Shifting climatic regimes can increase or decrease the frequency of extreme hydrologic events (e.g., high and low streamflows) causing large societal and environmental impacts. The impacts are numerous and include human health and safety, the destruction of infrastructure, water resources, nutrient and sediment transport, and within stream ecological health. It is unclear how the hydrology of a given region will shift in response to climate change. This is especially the case in areas that are seasonally snow covered as the interplay of changing temperature, precipitation, and resulting snowpack can lead to an increased risk of flood or drought.

This research …

Oxygen-Sensitive Luminophores: A Survey Of The Literature And Efforts Toward A Novel Porphyrin-Pillared Zirconium Phosphonate, Joseph Wright

Graduate College Dissertations and Theses

Measurement and mapping of the pressure distribution across the surface of a suitably scaled model is an integral step in the design of any aircraft or automobile. For this purpose, the traditional workhorses of the aeronautic and automotive industries have been pressure taps--small orifices that contain electronic pressure transducers. Unfortunately, in addition to the limited spatial resolution achievable with such devices, their technical complexity and cost constitute serious disadvantages. For more than 35 years, researchers have pursued a fundamentally different alternative: indirect measurement of pressure via oxygen-induced quenching of the luminescence emitted by certain chemical species. Porphyrin complexes of dipositive …

Impacts Of Transportation Infrastructure On Stormwater And Surface Waters In Chittenden County, Vermont, Usa, Joseph Hollis Bartlett

Graduate College Dissertations and Theses

Transportation infrastructure is a major source of stormwater runoff that can alter hydrology and contribute significant loading of nutrients, sediment, and other pollutants to surface waters. These increased loads can contribute to impairment of streams in developed areas and ultimately to Lake Champlain. In this study we selected six watersheds that represent a range of road types (gravel and paved) and road densities (rural, suburban, and urban) present in Chittenden County, one of the most developed areas in Vermont. The location and density of road networks were characterized and quantified for each watershed using GIS analysis. Monitoring stations in each …