Digital Commons Network^™

Raidx: Raid Extended For Heterogeneous Arrays, Andras Fekete

Doctoral Dissertations

The computer hard drive market has diversified with the establishment of solid state disks (SSDs) as an alternative to magnetic hard disks (HDDs). Each hard drive technology has its advantages: the SSDs are faster than HDDs but the HDDs are cheaper. Our goal is to construct a parallel storage system with HDDs and SSDs such that the parallel system is as fast as the SSDs. Achieving this goal is challenging since the slow HDDs store more data and become bottlenecks, while the SSDs remain idle. RAIDX is a parallel storage system designed for disks of different speeds, capacities and technologies. …

Adsorption Of Benzyl Viologen And Polyethylene Glycol And Their Displacement By 3-Mercapto-1-Propanesulfonate During Copper Electrodeposition, Jing Lu

Doctoral Dissertations

The fabrication of on-chip interconnects in the semi-conductor industry employs electrodeposition of copper for fabrication of lines and vertical interconnects (vias) on scales as small as a few tens of nanometers. A significant challenge is to control the distribution of current to assure void-free bottom up filling of these features, a process commonly referred to as superfilling. The presence of a combination of additives on the copper surface regulates the copper deposition rate, and in the proper concentrations produce a high deposition rate at the bottom of features and a reduced deposition rate on the planar wafer surface and upper …

Effects Of Alien Shrubs On Caterpillars And Shrubland-Dependent Passerines Within Three Transmission Line Rights-Of-Way In Southeastern New Hampshire, Matthew Tarr

Doctoral Dissertations

By altering plant species composition and reducing plant species richness, invasion of non-native (alien) plants can reduce caterpillar abundance in bird habitats and simplify the bird community, but whether these cascading effects of alien plants extend further to affect bird productivity has not been quantified. This study is the first to quantify how reduced caterpillar abundance associated with alien plant invasion affects the reproductive success of a breeding passerine, the common yellowthroat (Geothlypis trichas trichas). The study was conducted in three transmission line rights-of-way where plant composition in yellowthroat territories was dominated by a near monoculture of alien shrubs (“ALIEN” …

Brauer-Picard Groups And Pointed Braided Tensor Categories, Costel Gabriel Bontea

Doctoral Dissertations

Tensor categories are ubiquitous in areas of mathematics involving algebraic structures. They appear, also, in other fields, such as mathematical physics (conformal field theory) and theoretical computer science (quantum computation). The study of tensor categories is, thus, a useful undertaking.

Two classes of tensor categories arise naturally in this study. One consists of group-graded extensions and another of pointed tensor categories. Understanding the former involves knowledge of the Brauer-Picard group of a tensor category, while results about pointed Hopf algebras provide insights into the structure of the latter.

This work consists of two main parts. In the first one we …

Microbial Community And Vibrio Parahaemolyticus Population Dynamics In Relayed Oysters, Michael Anthony Taylor

Doctoral Dissertations

The CDC estimates that 45,000 people are sickened each year by foodborne Vibrio parahaemolyticus in the United States. Filter-feeding bivalve shellfish, such as oysters, are routinely inhabited by human pathogenic V. parahaemolyticus and there currently is not a contaminant management process that effectively reduces concentrations of V. parahaemolyticus in oysters. The transplanting of V. parahaemolyticus -laden oysters to an area with low concentrations or no V. parahaemolyticus, called oyster relay, is one reduction strategy that holds promise for treating live oysters. A key consideration for effective strategies to reduce Vibrio spp. in shellfish is the influence of microbiota in natural …

Development Of Novel Bio- And Heterogeneous Catalysts For The Production Of Bio- And Green Diesel, Ye Deng

Doctoral Dissertations

Diminishing petroleum reserves and increasing environmental awareness has led to an urgent need to develop alternative fuels, such as biodiesel. Enzymatic trans/-esterification of waste cooking oils with a lipase catalyst is a promising environmentally-friendly process to produce biodiesel, compared to the current industrial chemical process. Despite several advantages, there are a few technical and economical obstacles that limit this process, such as insufficient availability of large quantities of inexpensive lipase suitable for catalysis, and bad performance at low temperatures due to biodiesel’s low cetane number. These limitations are addressed in this dissertation using genetic engineering of plants to produce the …

Biophysical Mechanisms Of Rhythm Generation In The Pre-Bötzinger Complex, Ryan S. Phillips

Doctoral Dissertations

The pre-Bötzinger complex (pre-BötC) is an essential rhythmogenic brainstem nucleus located in the ventrolateral medulla. Rhythmic output from the pre-BötC is relayed through premotor and motor neurons to the diaphragm and intercostal muscles to drive the active inspiratory phase of breathing. The specific biophysical mechanisms responsible for generating rhythmic bursting and network synchronization are not well understood and remain a highly debated topic within the field. Through extensive experimental and theoretical work two plausible rhythmogenic mechanisms have emerged. One mechanism is based on a slowly inactivating persistent sodium current (INaP) and the other on a calcium activated non-selective cation current …

Cracking In Asphalt Pavements: Impact Of Component Properties And Aging On Fatigue And Thermal Cracking, Reyhaneh Rahbar-Rastegar

Doctoral Dissertations

Cracking in asphalt pavements is one of the most common and critical pavement distresses. Cracks let the water penetrate from the surface to underlying layers resulting in shorter pavement service life and poor riding quality. There are various factors that affect the cracking potential of asphalt mixtures including the properties of asphalt components, mix design factors, loading time and loading mode, temperature, stress state, and aging. While several researchers have conducted studies investigating the cracking of asphalt mixtures, the effective parameters are not all well understood to allow engineers to design and construct more resistant pavements against cracking.

The work …

Effects Of Agricultural Practices On Soil Communities And Their Associated Ecosystem Services, Lesley W. Atwood

Doctoral Dissertations

To maximize crop yields, commodity crop production systems typically rely on inputs of fertilizers, pesticides, and irrigation; simplification of crop rotations (e.g., monocultures); and strategic use of soil disturbance (e.g., tillage, cultivation, etc.). While these practices are intended to optimize the soil conditions for crop development and reduce spatial and temporal variability in crop yield, they also impact soil biological diversity and the important agroecosystem services soil communities provide. Identification of management practices that are less prone to causing undesirable changes in the soil food web community are central to improving the sustainability of our agricultural systems. In this dissertation, …

Numerical And Physical Modeling Of Cone Penetration In Unsaturated Soils And Numerical Simulation Of Fracture Propagation In Shale Rock During Brazilian Test, Pegah Jarast Shamsabadi

Doctoral Dissertations

Partially water saturated condition in soils may change the cone penetration resistance comparing with that of dry or saturated conditions. This effect was investigated in this study using numerical finite element modeling and experimental centrifuge testing. The results showed suction in unsaturated soil significantly influenced the soil resistance to cone penetration. Two approaches were implemented to numerically consider the partially saturated soil condition; i.e. modifying simple constitutive models using an apparent cohesion strategy and implementing Barcelona Basic Model for unsaturated soils. Both successfully captured the cone resistance profiles inside a calibration chamber and also in free field. In addition, details …

Patterns And Drivers Of Carbon Fluxes In Temperate Forests, Andrew Ouimette

Doctoral Dissertations

Despite decades of carbon cycling research in terrestrial ecosystems, a complex suite of biotic and abiotic interactions make a complete understanding of the natural carbon cycle elusive. This thesis aims to advance our understanding of the carbon cycle, and stems from several ongoing projects aimed at quantifying carbon dynamics in forest ecosystems across a range of scales, with a specific effort to include both above and belowground components of forest ecosystems. I begin with a project using detailed chemical measurements on specific segments of root systems from two different tree species, in order to help refine methods that quantify the …

Hilic-Ms/Ms Method Development For The Analysis Of Select Paralytic Shellfish Toxins In Shellfish Harvested From New Hampshire Coastal Waters, Jessica Henry

Doctoral Dissertations

A hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS) method was developed for the analysis of select paralytic shellfish poisoning (PSP) toxins: decarbamoylsaxitoxin (dcSTX), neosaxitoxin (NEO), and saxitoxin (STX). The method employs a bare silica core-shell stationary phase and isocratic elution conditions to achieve chromatographic separation of the selected toxins. The HILIC-MS/MS method was applied to the analysis of sixteen mussel samples harvested from the New Hampshire coastline during the 2016 harvest season. Of these selected mussel samples analyzed, STX was detected in all of the samples; NEO was detected in two samples; and dcSTX was not detected in any sample. …

Affect In The Classroom: A Psychoanalytic And Cultural Exploration Of Social And Emotional Learning, Clio Stearns

Doctoral Dissertations

This dissertation explores the contemporary educational construct known as Social and Emotional Learning, or SEL. It investigates how the child, the teacher and the relationship between children and teachers are figured in the SEL-managed classroom. The dissertation also examines the extent to which SEL is produced by, and productive of, culture, as well as what becomes of negative and unruly affect in the context of SEL. The dissertation triangulates data from Critical Discourse Analysis of selected SEL materials, classroom observations in two different public school elementary school classrooms, and interviews with participating teachers. A combination of Kleinian psychoanalysis and affect …

Improving The Understanding Of Different Diets On The Concentration And Metabolism Of The Mammalian Lignan Enterolactone In Dairy Cattle, Caren Paludo Ghedini

Doctoral Dissertations

Flaxseed (Linum usitatissimum) is the richest source of the plant lignan secoisolariciresinol diglucoside (SDG), which is precursor for the synthesis of the mammalian lignans enterolactone (EL) and enterodiol (ED) by the gastrointestinal microbes in mammals. There is a great deal of interest in promoting increased intakes of lignans in humans’ diet due to their potential health benefits, especially in the prevention of cardiovascular diseases, hypercholesterolaemia, breast and prostate cancers, and osteoporosis. Consumption of milk and dairy products enriched in EL could be an excellent strategy to increase the intake of lignans by humans. The first (Chapter II) and second (Chapter …

Examining The Benefits Of Instructional Assessment As Experienced By Secondary Mathematics Teachers, Willem Wallinga

Doctoral Dissertations

Mathematics teachers use a wide variety of assessment tools and methods to measure student understanding and illuminate potential learning gaps (NCTM, 2014). The most frequent and least formal types occur as observations and interactions that provide immediate feedback on the learning process (NRC, 2003, Wiliam, 2007). These Instructional Assessments emerge within the social environment of classroom activity, and serve a formative function by directly impacting the flow of discussion and motivating appropriate teaching interventions. Research has shown that formative assessment improves student performance, but is often challenging for teachers to master (OECD, 2005). The influence of annual high-stakes testing in …

Nitrogen Dynamics And Retention In The River Network Of A Tropical Forest, Luquillo Mountains, Puerto Rico, Richard Brereton

Doctoral Dissertations

This dissertation identifies gaps in the scientific understanding of nutrient cycling, particularly nitrogen (N) cycling, in streams and riparian zones of tropical montane forests, and addresses several of those gaps with original field-based research using study watersheds in the Luquillo Mountains of Puerto Rico as the model system. The Luquillo Mountains have features typical of mature montane tropical forests, such as high background N concentrations in streams and groundwater relative to streams in other biomes. As a USDA Forest Service Experimental Forest, the Luquillo Mountains are accessible to researchers and have abundant monitoring and experimental datasets from which to build …

The Proton Spin Structure Function G2p At Low Momentum Transfer, Tobias Badman

Doctoral Dissertations

Over the past several decades Jefferson Lab National Accelerator Facility has proven to be extremely successful in its endeavor to study the polarized structure of nucleons. Measurements of these nucleon structure functions have proven to be powerful tools in testing and understanding a number of effective theories of QCD. The neutron spin structure functions, g1n and g2n, and the proton spin structure function, g1p, have been measured to very high precision over a wide kinematic range. However, the second proton structure function, g2p, remained largely unmeasured. The primary goal of Jefferson Lab Hall A experiment E08-027 was to perform an …

The G2p Experiment: A Measurement Of The Proton's Spin Structure Functions, Ryan Zielinski

Doctoral Dissertations

The E08-027 (g2p) experiment measured the spin structure functions of the proton at Jefferson Laboratory in Newport News, Va. Longitudinally polarized electrons were scattered from a transversely and longitudinally polarized solid ammonia target in Jefferson Lab's Hall A, with the polarized NH₃ acting as an effective proton target. Focusing on small scattering angle events at the electron energies available at Jefferson Lab, the experiment covered a kinematic phase space of 0.02 GeV² < Q² < 0.20 GeV² in the proton's resonance region. The spin structure functions, g₁^p(x,Q²) and g₂^p(x,Q²) , are …

Unraveling Short-Term Variations In Tidewater Glacier Flow: Insights From Terrestrial Radar Interferometric Studies, Ryan Cassotto

Doctoral Dissertations

Tidewater glaciers are fast-flowing valley glaciers that advect ice from the interior of ice sheets to the ocean. Processes along the submarine boundaries of tidewater glacier termini can trigger a dynamic response in glacier ice that can impact stability along the terminus. Predictions of 21st century sea level rise require a comprehensive understanding of tidewater glacier dynamics over a variety of spatial and temporal scales. Perturbations to the calving front, such as iceberg calving, tidal modulations, changes in proglacial ice mélange strength and rigidity, and the subglacial discharge of meltwater occur on time-scales that exceed temporal resolution of satellite measurements; …

Self-Similar Properties And Leading Balance Scaling Structure Of Wall-Bounded Turbulent Flows, Ang Zhou

Doctoral Dissertations

Wall-bounded turbulent flows are ubiquitous in numerous technological applications, and thus much effort has been devoted to investigate their properties. Scaling analyses involving the application multiple-scale approaches are effectively used to explore parameters (Reynolds, Prandtl numbers) dependent scaling behaviors of these flows. The objective of this dissertation research is to firstly extend the analysis of self-similar behaviors on the inertial domain as admitted by the mean dynamics in wall-bounded turbulent flows (WBTF). It then mathematically and physically characterizes the existence of a leading order balance structure in both the kinetic energy and passive scalar transport budgets, and subsequently uses this …

Nature Of Formal Intimate Partner Violence Help Seeking: The Influence Of Individual And Community Characteristics, Desiree Ruth Wiesen-Martin

Doctoral Dissertations

Intimate partner violence is a public health concern, and intimate partner violence victim help seeking is the focus of many intervention/prevention policies and programs. Help seeking by victims of intimate partner violence from formal support services, such as the police, domestic violence shelters, and/or rape crisis centers, is relatively low (Kaukinen 2002; Davies, Block, and Campbell 2007; Campbell 2008; Kaukinen, Meyer, and Akers 2013; Zaykowski 2014), and the research which considers the nature of help seeking among those victims who seek help is quite limited. This dissertation investigates the nature of formal help seeking among intimate partner violence victims who …

Size-Sensitive Crystal Plasticity Finite Element Framework For Simulating Behavior Of Lamellar Metal-Metal Composites, Milan Ardeljan

Doctoral Dissertations

Growing demands for materials with enhanced and superb characteristics increase the difficulty and the amount of research necessary to be conducted in many different areas of expertise. The vast field of computational mechanics represents a significant source of valuable solutions to many of these challenges and can provide a smoother transition in the process when a new material is introduced. Experimental techniques are not always able to measure the localized material features due to the very complicated deformation conditions. As an alternative approach, full-field models are developed, such the ones contained in this dissertation that can bridge this gap and …

Evaluating Satellite Derived Bathymetry In Regard To Total Propagated Uncertainty, Multi-Temporal Change Detection, And Multiple Non-Linear Estimation, Ricardo Ramos Freire

Doctoral Dissertations

Acoustic and electromagnetic hydrographic surveys produce highly-accurate bathymetric data that can be used to update and improve current nautical charts. For shallow-water surveys (i.e., less than 50m depths), this includes the use of single-beam echo-sounders (SBES), multi-beam echo-sounders (MBES), and airborne lidar bathymetry (ALB). However, these types of hydrographic surveys are time-consuming and require considerable financial and operational resources to conduct. As a result, some maritime regions are seldom surveyed due to their remote location and challenging logistics.

Satellite-derived bathymetry (SDB) provides a means to supplement traditional acoustic hydrographic surveys. In particular, Landsat 8 imagery: 1) provides complete coverage of …

Simulation Studies Of Signaling And Regulatory Proteins, Hossein Mohammadiarani

Doctoral Dissertations

I used molecular dynamics (MD) simulations as a primary tool to study folding and dynamics of signaling and regulatory proteins. Specifically, I have studied two classes of proteins: the first part of my thesis reports studies on peptides and receptors of the insulin family, and the second part reports on studies of regulatory proteins from the G-protein coupled receptor family. The first problem that I investigated was understanding the folding mechanism of the insulin B-chain and its mimetic peptide (S371) which were studied using enhanced sampling simulation methods. I validated our simulation approaches by predicting the known solution structure of …

A Study Of The Surface Structure Of Polymorphic Graphene And Other Two-Dimensional Materials For Use In Novel Electronics And Organic Photovoltaics, Maxwell Charles Grady

Doctoral Dissertations

For some time there has been interest in the fundamental physical properties of low- dimensional material systems. The discovery of graphene as a stable two-dimensional form of solid carbon lead to an exponential increase in research in two-dimensional and other re- duced dimensional systems. It is now known that there is a wide range of materials which are stable in two-dimensional form. These materials span a large configuration space of struc- tural, mechanical, and electronic properties, which results in the potential to create novel electronic devices from nano-scale heterostructures with exactly tailored device properties. Understanding the material properties at the …

The Identification Of Major Factors In The Deployment Of A Science Dmz At Small Institutions, Scott A. Valcourt

Doctoral Dissertations

The Science DMZ is a network research tool offering superior large science data transmission between two locations. Through a network design that places the Science DMZ at the edge of the campus network, the Science DMZ defines a network path that avoids packet inspecting devices (firewalls, packet shapers) and produces near line-rate transmission results for large data sets between institutions. Small institutions of higher education (public and private small colleges) seeking to participate in data exchange with other institutions are inhibited in the construction of Science DMZs due to the high costs of deployment. While the National Science Foundation made …

Smart Buildings: An Integrative Double Skin Façade Damper System For Safety And Energy Efficiency, Rui Zhang

Doctoral Dissertations

A smart building is an intelligent living space that elevates energy efficiency, comfort and safety. The word “smart” implies that the building would have a decision making system that can sense its conditions and reacts to them in an automatic and effective manner. Modem buildings contain many subsystems and, thus, to achieve automation, sophisticated sensing networks and robust control systems must be installed. The proposed research focuses on integrating several building systems — structural health monitoring (SHM), and structural and environmental controls — and explores synergy among them to improve efficiency and sustainability of buildings.

More specifically, an integrative, smart …

Statistical Properties And Applications Of Empirical Mode Decomposition, Mahdi Hameed Al-Badrawi

Doctoral Dissertations

Signal analysis is key to extracting information buried in noise. The decomposition of signal is a data analysis tool for determining the underlying physical components of a processed data set. However, conventional signal decomposition approaches such as wavelet analysis, Wagner-Ville, and various short-time Fourier spectrograms are inadequate to process real world signals. Moreover, most of the given techniques require \emph{a prior} knowledge of the processed signal, to select the proper decomposition basis, which makes them improper for a wide range of practical applications. Empirical Mode Decomposition (EMD) is a non-parametric and adaptive basis driver that is capable of breaking-down non-linear, …

Exploring The Socio-Ecological Dimensions Of Agricultural Expansion In New Hampshire, Jennifer Wilhelm

Doctoral Dissertations

Forest ecosystems and agriculture represent coupled socio-ecological systems that are shaped by human activity. The extensification of agriculture (expansion of food production on the landscape) can cause significant changes in land use, and can contribute to the degradation of biodiverse ecosystems and the services these systems provide. Yet the need to increase food production capacity, either through agricultural intensification or extensification, continues to rise. In this dissertation, I address the critical issue of agricultural extensification from several angles.

The first chapter assesses agricultural expansion through the lens of urban and peri-urban agriculture (UPA) through systematic review of the literature. I …

A Dynamical-Systems Approach To Understanding Turbulence In Plane Couette Flow, Mimi Szeto

Doctoral Dissertations

Dynamical systems theory is used to understand the dynamics of low-dimensional spatio-temporal chaos. Our research aimed to apply the theory to understanding turbulent fluid flows, which could be thought of as spatio-temporal chaos in a very-high dimensional space. The theory explains a system's dynamics in terms of the local dynamics of its periodic solutions; these are the periodic orbits in state space. We considered the development of a model for the dynamics of plane Couette flow based on the theory. The proposed model is essentially a set of low-dimensional models for the local dynamics of the periodic orbits of the …