Physical Sciences and Mathematics Commons^™

Conifer Establishment And Encroachment On Subalpine Meadows Around Mt. Baker, Wa, Ben Hagedorn

WWU Graduate School Collection

The subalpine ecotone is experiencing significant change in habitat availability and connectivity as a result of climate change and climate variability. To understand how these changes vary temporally and spatially in the Pacific Northwest, we collected cross-sections and counted whorls of conifers along four transects around Mt. Baker, Washington in the North Cascades. In addition to the samples collected, we also gathered data on microsite conditions that impact seedling establishment. Using partial correlation analyses, we compared establishment dates to climate variables in five-year bins, and used normal correlation analyses along with other statistical tests to determine the effect of various …

Modeling The Effects Of Climate Change On Streamflow And Stream Temperature In The South Fork Of The Stillaguamish River, Katherine Mary Clarke

WWU Graduate School Collection

The Stillaguamish River in northwest Washington State is an important regional water resource for local agriculture, industry, and First Nations tribes and a critical habitat for several threatened and endangered salmonid species, including the Chinook salmon. The river is currently subject to a temperature total maximum daily load, so it is important to understand how projected climate change will affect future stream temperatures and thus salmon populations. Snowpack is the main contributor to spring and summer streamflow and helps to mitigate stream temperatures as air temperatures rise through the summer in the South Fork of the Stillaguamish River. I used …

Crystal Mush Dynamics Of Mount St. Helens And Lassen Volcanic Center: Insights From Melt Inclusions And Titanium-In-Quartz Thermobarometry, Jeremy S. Rosen

WWU Graduate School Collection

In order to better understand magma chamber dynamics at Lassen Volcanic Center (LVC) and Mount St. Helens (MSH) I examine quartz cathodoluminescent textures along with trace element abundances in quartz and compositions of quartz-hosted melt inclusions from multiple samples over a wide range of ages (LVC: 116 ka-1915; MSH: 272 ka to 84 ka). I use melt inclusion compositions to estimate quartz crystallization temperatures using zircon saturation thermometry and titanium abundances in quartz are used to estimate quartz crystallization pressures. When examined from core to rim within an individual grain, these data, along with internal CL-zoning textures reveal the dynamic …

Synthesis And Characterization Of Earth Abundant Metal Phosphide Photocatalysts For The Reverse Water Gas Shift Reaction, John D. Springer

WWU Graduate School Collection

This thesis work focuses on the synthesis and characterization of photocatalysts composed of metal phosphide nanoparticles on a titania (TiO2) support for the conversion of carbon dioxide (CO2) to carbon monoxide (CO) via the reverse water gas shift (RWGS) reaction. The CO product can be subsequently converted to solar fuels such as methanol (CH3OH), thus lowering the carbon footprint associated with the combustion of liquid fuels. The photocatalysts are composed of a tunable light absorber, indium-gallium phosphide (InxGa1-xP), and nickel phosphide (Ni2P) as a co-catalyst, on TiO2. The photocatalysts are characterized using diffuse reflectance ultraviolet-visible (UV-Vis) spectroscopy to determine band …

Incorporating Climate Change Predictions In Ecological Risk Assessment: A Bayesian Network Relative Risk Model For Chinook Salmon In The Skagit River Watershed, Eric J. Lawrence

WWU Graduate School Collection

Climate change is expected to have widespread impacts on future ecosystem services in the Puget Sound and around the world. It is important that climate change be included in ecological risk assessment so that changing climate variables and potential interactive effects with chemical stressors can be taken into account. In this research, I focused on the question of how water temperature changes generated by climate change interact with organophosphate pesticide toxicity to affect Chinook salmon (Oncorhynchus tshawytscha) population size in the Skagit River, WA. To answer this question, I conducted an ecological risk assessment using the Bayesian network …

Carbodiimides: Templates For Covalent Adaptable Networks And Post Polymerization Modification, Alberto J Melchor Bañales

WWU Graduate School Collection

The global increase in plastic waste has negatively impacted the environment, human health, and economy. Plastics that lack recyclability, such as thermosets are some of the main culprits. To help address this issue, reactive functional groups can be incorporated in macromolecules, enabling straightforward post-polymerization modification (PPM) that can enhance their ability to be recycled. This thesis studied carbodiimides as a reactive functional group for facile PPM with amines through a catalyst-free transformation to N,Nʹ,Nʺ-trisubstituted guanidines. Small molecule studies showed that N,Nʹ,Nʺ-trisubstituted guanidines underwent a reversible thermal exchange reaction without a catalyst. The newly found thermal exchange reaction, termed thermal guanidine …

Bio-Preservation Potential Of Sediment In Eberswalde Crater, Mars, Cory Hughes

WWU Graduate School Collection

Within Eberswalde crater, Mars, is one of the most well-preserved river delta deposits identified within Mars’ rock record, and visually traceable from the deposit, is the partially-intact watershed that fed the paleo-lake that once resided within the crater basin. Aqueous alteration minerals, smectite clays and opaline silica, have been previously identified within the deposit, however the origin of those minerals is not well understood. Through analysis of topographic and hyperspectral data, we seek to ascertain the origin and provenance of these minerals to better understand their formative conditions and formation age. We will also assess Eberswalde crater’s potential as a …

Can Arbuscular Mycorrhizal Fungi Protect Rubus Idaeus From The Effects Of Soil-Borne Disease And Parasitic Nematodes?, Erika Whitney

WWU Graduate School Collection

Chemical controls for agricultural pests and diseases can have detrimental effects on human health and the environment. One alternative is to introduce soil microbes, such as arbuscular mycorrhizal fungi (AMF), that can improve crop resilience to pests and pathogens. While many plants form symbioses with AMF, not all crops benefit from inoculation. We conducted three studies that questioned the effect of AMF from various sources on R. idaeus growth and resilience to pests/pathogens. First, in a small observational study, we investigated whether AMF colonization of raspberry roots covaried with stand vigor. In two subsequent greenhouse experiments, we asked (1) if …

Clam Garden Bivalve Dietary Responses And Trophic Shifts In Relation To Environment, Octavio Cruz

WWU Graduate School Collection

Clam gardens are a method of Indigenous aquaculture, involving altering of beach gradients, to increase clam habitat that have been used since pre-contact. Ecological examinations of clam gardens have been increasingly led by First Nations groups, as restoration projects begin on clam gardens aiming to re-establish pre-contact conditions.

The purpose of this study was to measure condition indices of traditionally-harvested littleneck clams (Leukoma staminea), dietary parameters and beach-level oceanographic conditions were used to investigate differences between clam gardens from non-walled beaches in Kanish Bay, Quadra Island, British Columbia. I utilized non-metric multidimensional scaling, distance-based redundancy analysis, and Bayesian 3-source isotopic …

Slip Rates And Kinematics Of Active Crustal Faults In The Central Oregon Cascades, Katherine Alexander

WWU Graduate School Collection

New cosmogenic ³He chronologies and surficial geologic mapping constrain the age of glacial deposits and slip rates of predominantly normal faults in the White Branch and Dilman Meadows fault zones in central Oregon, USA, over the last ca. ~80 kyr. Our mapping of glacial landforms and deposits distinguishes three primary episodes of glacial deposition in the White Branch fault zone. Twenty-two new cosmogenic ³He surface exposure dates indicate that the youngest glacial unit represents a last glacial maximum deposit (ca. 19.4 +10.1/-6.2 kyr). Mapping of outwash terrace surfaces and deposits in the Dilman Meadows fault zone, constrained by …

Timing And Conditions Of Metamorphism In The Cascades Crystalline Core From Garnet Lu-Hf And Sm-Nd Geochronology, Peter Baker

WWU Graduate School Collection

The Chiwaukum Schist and Tonga Formation of Cascades Crystalline Core experienced three distinct metamorphic events: (M1) an early metamorphism that predates regional pluton emplacement, (M2) low-pressure contact metamorphism in the aureoles of the Mount Stuart batholith and Beckler Peak pluton, and (M3) regional Barrovian metamorphism. The timing of these distinct metamorphic events is critical to testing models for the tectonic evolution of the region and mechanisms that lead to burial of rocks within the orogen. I present new garnet Lu-Hf and Sm-Nd isochrons, average pressure and temperature calculations, and pseudosection modeling from the Chiwaukum Schist and Tonga Formation in order …

Polybenzoxazine-Grafted Composites: Accelerated Polymerization Of Benzoxazine Resins From Bulk- To Microscale Mesylated Materials, Cassidy L. Crickmore

WWU Graduate School Collection

Benzoxazine-based resins often afford high modulus and high glass transition polymers that are desirable for creating safe and reliable thermoset parts and composites. However, benzoxazine resins have had limited widespread deployment into industry due to their high cure temperature. By blending functionalized glass substrates with the benzoxazine monomer, we hypothesize that the cure temperature of thermosetting resin can be lowered. The structure and purity of the particles, determined by NMR and FTIR, will be presented. DSC studies on the stability and cure accelerating properties of blends composed of functionalized glass substrates and benzoxazine monomer will be determined and compared against …

Integrating Synthetic Biology Derived Variables Into Ecological Risk Assessment Using The Bayesian Network – Relative Risk Model: Gene Drives To Control Nonindigenous M. Musculus On Southeast Farallon Island, Ethan A. Brown

WWU Graduate School Collection

Ecological risk assessment has not been conducted for the proposed environmental applications of synthetic biology. To develop a quantitative framework for risk assessment of synthetic biology, I selected Southeast Farallon Island as a case study for modeling the deployment of gene drive modified house mice to reduce impacts to threatened species. Southeast Farallon Island is part of the Farallon Islands National Wildlife Refuge. The island is populated by invasive house mice that impact indigenous species. Gene drive technology has been proposed as a method to suppress invasive rodent populations through CRISPR-mediated genome editing. I applied the Bayesian Network – Relative …

Forest Restoration Of The Exposed Lake Mills Bed: Assessing Vegetation, Ectomycorrhizae, And Nitrogen Relative To Riverbank Lupine (Lupinus Rivularis), James Kardouni

WWU Graduate School Collection

This thesis investigated the managed revegetation outcomes of the exposed Lake Mills reservoir bed was investigated following the Glines Canyon dam removal on the Elwha River located in the Pacific Northwest, United States. During the following four years of restoration, one seeded species, riverbank lupine (Lupinus rivularis), quickly established on the coarse textured terraces that also had low organic matter (OM) and low soil nitrogen (N) levels. Nitrogen-fixing lupines may facilitate plant recruitment and conifer establishment, while demonstrating a relationship with ectomycorrhizal (ECM) communities which perform essential forest ecosystem functions. The purpose of this study was to investigate lupine’s influence …

Fast Decision-Making Under Time And Resource Constraints, Kyle Gabriel Lassak

Graduate Theses, Dissertations, and Problem Reports

Practical decision makers are inherently limited by computational and memory resources as well as the time available in which to make decisions. To cope with these limitations, humans actively seek methods which limit their resource demands by exploiting structure within the environment and exploiting a coupling between their sensing and actuation to form heuristics for fast decision-making. To date, such behavior has not been replicated in artificial agents. This research explores how heuristics may be incorporated into the decision-making process to quickly make high-quality decisions through the analysis of a prominent case study: the outfielder problem. In the outfielder problem, …

Knickzones In Southwest Pennsylvania Streams Indicate Accelerated Pleistocene Landscape Evolution, Mark D. Swift

Graduate Theses, Dissertations, and Problem Reports

A set of 22 southwestern Pennsylvania streams flowing into the Monongahela and Ohio rivers with drainage areas ranging from 8 km² to >512 km² exhibit knickzones, when compared to Mackin’s (1948) idealized graded stream profile. Watersheds delineated from LiDAR-derived 1 m DEMs were processed using Esri’s ArcGIS for Desktop 10.6 to extract stream elevation data used to create stream profiles. These data were exported to MS Excel, where gradients were calculated and compared. This study used a new methodology in which gradient was calculated using incremental measurement distances (d) at every meter along the length of …

Disturbance Related To Unconventional Oil And Gas Development In The Appalachian Basin, Kevin Jordan Harris

Graduate Theses, Dissertations, and Problem Reports

Little research has been done on the land cover change of unconventional oil and gas (UOG) wells across the Appalachian basin. In the last decade, UOG development has increased drastically across the region. Permitted well data from 2007 to 2017 were assembled into a geospatial database and analyzed with current aerial imagery to determine the activity of permitted wells in Ohio, Pennsylvania, and West Virginia. To capture all disturbance related to UOG development, a 25-hectare buffer was placed around each active well as the study extent. A supervised classification approach was used to determine the pre-development and post-development landcover across …

Estimating Evolutionary Volatility In A Maximum-Likelihood Framework, Samuel Warren Tybout

Graduate Theses, Dissertations, and Problem Reports

Evolutionary volatility is a trait that encompasses a clade’s combined capacity for origination and extinction. High volatility increases extinction risk, and declining global extinction rates are thought to be linked to declining volatility. Despite volatility’s scientific importance, there is no standardized way of measuring it. This study provides a new method, derived from a stochastic birth-death model, of estimating evolutionary volatility from fossil data. Simulations indicate that the method produces accurate and precise estimates for large fossil datasets. Analysis of fossil data for five bivalve families (Lucinidae, Mytilidae, Pectinidae, Pholadomyidae, and Veneridae) indicates that diversity projections made from the estimates …

Leaf Angle And Leaf Stomata Responses To Experimental Drought In Quercus Velutina And Acer Saccharum, Brittany Nichole Casey

Graduate Theses, Dissertations, and Problem Reports

The possibility of increased severity and frequency of drought conditions, as a result of global climate variability, greatly complicates our ability to forecast future forest functions such as productivity and carbon sequestration. Assessing how tree species vary in their response to drought can aid in predicting the impact on forest ecosystems as a whole. Throughfall exclusion (TfE) experiments are potentially useful tools to simulate realistic drought conditions within intact forest ecosystems. We employed a TfE experiment during the 2018 growing season within the WV Land Trust’s Elizabeth’s Woods Nature Preserve, near Morgantown, WV, to assess the leaf angle and leaf …

Numerical Analysis And Gravity, Tyler D. Knowles

Graduate Theses, Dissertations, and Problem Reports

In this dissertation we apply techniques of numerical analysis to current questions related to understanding gravity. The first question is that of sources of gravitational waves: how can we accurately determine the intrinsic physical parameters of a binary system whose late inspiral and merger was detected by the Laser Interferometer Gravitational-Wave Observatory. In particular, state-of-the-art algorithms for producing theoretical waveforms are as many as three orders of magnitude too slow for timely analysis. We show that direct software optimization produces a two order of magnitude speedup. We also describe documentation efforts undertaken so that the software may be rewritten to …

Relating Sonic Velocities, Minimum Horizontal Stress, And Natural Fracture Distribution To Stimulation Efficiency During Completion Of The Marcellus Shale Mip-3h Unconventional Well, West Virginia, Usa, Kaitlin Gayle Evans

Graduate Theses, Dissertations, and Problem Reports

Log data from the Marcellus Shale Energy and Environment Laboratory (MSEEL) was acquired along the lateral of the MIP-3H well. This unconventional shale-gas well was completed within the Marcellus Shale just above the Cherry Valley Limestone, a thin limestone member separating organic rich units of the Marcellus. The geomechanical moduli, Poisson’s Ratio (PR) and Young’s Modulus (YME), were generated using compressional and shear sonic logs to indicate zones of increasing brittleness for each of the 28 stages along the 6124 ft. (1867m) horizontal lateral. Brittle reservoir rock is more readily fractured during hydraulic stimulation than more malleable rock. Stages with …

Control Of Charged Particle Dynamics And Electron Power Absorption Dynamics Utilizing Voltage Waveform Tailoring In Capacitively Driven Radio-Frequency Plasmas, Steven W. Brandt

Graduate Theses, Dissertations, and Problem Reports

In this work, experimental measurements and analysis of numerical simulations are performed for capacitively coupled plasmas driven by tailored voltage waveforms under conditions which examine complicating factors present in industrial processes, including the influence of resonance effects, electronegative gases or gas mixtures, and plasma-surface interactions at a changing plasma-surface interface. Furthermore, the influence of different tailored voltage waveforms on the spatio-temporal electron power absorption, the generation of a DC self-bias, and on process relevant plasma parameters like ion energy distribution functions is investigated to provide a more complete understanding of the underlying fundamental plasma physics responsible for sustaining the discharge. …

Structural Characterization Of Emerging Synthetic Drugs, Jay Tyler Davidson

Graduate Theses, Dissertations, and Problem Reports

The identification of well-characterized seized drugs is performed thousands of times a day in the United States; however, the expanding use of emerging synthetic drugs is creating a growing problem for both toxicological and seized drug analyses. Two of the most rapidly growing areas of emerging synthetic drugs are synthetic cathinones and fentanyl-related compounds (FRCs). In this work we demonstrate the combination of multi-stage mass spectrometry (MSⁿ), accurate mass measurements with high-resolution mass spectrometry (HRMS), and isotopic labeling for the structural characterization of synthetic cathinones and fentanyl analogs. The deliverables of this research include the identification of conserved …

Reservoir Characterization And Static Earth Modeling For Potential Co2 Storage In Upper Pennsylvanian Cyclothems Of Midcontinent, Usa, Valerie Lynn Smith

Graduate Theses, Dissertations, and Problem Reports

This dissertation details the estimation of CO₂ storage volume using reservoir characterization and the building of static earth models in two papers: 1) for Sleepy Hollow Field in Red Willow County, Nebraska and, 2) for Huffstutter Field, Phillips County, Kansas. These models are used to obtain estimates of CO₂ storage capacity in stacked carbonate intervals of the Pennsylvanian Lansing and Kansas City groups (LKC). The LKC constitutes a regional succession of interbedded carbonates and shales. Located over the Cambridge Arch of Nebraska, these interbedded units were evaluated for carbon storage potential. Understanding the occurrence of carbonate porosity among …

Ultrafast Optical Properties Of La0.7sr0.3mno3 Thin Films, Saeed Yousefi Sarraf

Graduate Theses, Dissertations, and Problem Reports

Thin film solids often exhibit different physical properties in the ultra-thin regime. Enhancement of surface to bulk ratio results in the domination of surface/interface related phenomena such as surface recombination. Moreover, in the ultra-thin regime, quantum size and quantum confinement effects can alter the band gap of the system and constrain the strain wave propagation in the thin film. Ultrafast properties of solids can also be drastically altered in the ultra-thin regime due to the aforementioned phenomena. Experimentally, observation of these phenomena is challenging due to the insufficient material to absorb and interact with the electromagnetic wave. This dissertation addresses …

Circuits And Cycles In Graphs And Matroids, Yang Wu

Graduate Theses, Dissertations, and Problem Reports

This dissertation mainly focuses on characterizing cycles and circuits in graphs, line graphs and matroids. We obtain the following advances.

1. Results in graphs and line graphs. For a connected graph G not isomorphic to a path, a cycle or a K1,3, let pc(G) denote the smallest integer n such that the nth iterated line graph Ln(G) is panconnected. A path P is a divalent path of G if the internal vertices of P are of degree 2 in G. If every edge of P is a cut edge of G, then P is a bridge divalent path of G; …

Process Based Analysis Of Fluvial Stratigraphic Record: Middle Pennsylvanian Allegheny Formation, North-Central Wv, Oluwasegun O. Abatan

Graduate Theses, Dissertations, and Problem Reports

Fluvial deposits represent some of the best hydrocarbon reservoirs, but the quality of fluvial reservoirs varies depending on the reservoir architecture, which is controlled by allogenic and autogenic processes. Allogenic controls, including paleoclimate, tectonics, and glacio-eustasy, have long been debated as dominant controls in the deposition of fluvial strata. However, recent research has questioned the validity of this cyclicity and may indicate major influence from autogenic controls. To further investigate allogenic controls on stratal order, I analyzed the facies architecture, geomorphology, paleohydrology, and the stratigraphic framework of the Middle Pennsylvanian Allegheny Formation (MPAF), a fluvial depositional system in the Appalachian …

Elucidating The Properties And Mechanism For Cellulose Dissolution In Tetrabutylphosphonium-Based Ionic Liquids Using High Concentrations Of Water, Brad Crawford

Graduate Theses, Dissertations, and Problem Reports

The structural, transport, and thermodynamic properties related to cellulose dissolution by tetrabutylphosphonium chloride (TBPCl) and tetrabutylphosphonium hydroxide (TBPH)-water mixtures have been calculated via molecular dynamics simulations. For both ionic liquid (IL)-water solutions, water veins begin to form between the TBPs interlocking arms at 80 mol % water, opening a pathway for the diffusion of the anions, cations, and water. The water veins allow for a diffusion regime shift in the concentration region from 80 to 92.5 mol % water, providing a higher probability of solvent interaction with the dissolving cellulose strand. The hydrogen bonding was compared between small and large …

Interpretations Of Bicoherence In Space & Lab Plasma Dynamics, Gregory Allen Riggs

Graduate Theses, Dissertations, and Problem Reports

The application of bicoherence analysis to plasma research, particularly in non-linear, coupled-wave regimes, has thus far been significantly belied by poor resolution in time, and/or outright destruction of frequency information. Though the typical power spectrum cloaks the phase-coherency between frequencies, Fourier transforms of higher-order convolutions provide an n-dimensional spectrum which is adept at elucidating n-wave phase coherence. As such, this investigation focuses on the utility of the normalized bispectrum for detection of wave-wave coupling in general, with emphasis on distinct implications within the scope of non-linear plasma physics. Interpretations of bicoherent features are given for time series from …

Automated And Standardized Tools For Realistic, Generic Musculoskeletal Model Development, Trevor Rees Moon

Graduate Theses, Dissertations, and Problem Reports

Human movement is an instinctive yet challenging task that involves complex interactions between the neuromusculoskeletal system and its interaction with the surrounding environment. One key obstacle in the understanding of human locomotion is the availability and validity of experimental data or computational models. Corresponding measurements describing the relationships of the nervous and musculoskeletal systems and their dynamics are highly variable. Likewise, computational models and musculoskeletal models in particular are vitally dependent on these measurements to define model behavior and mechanics. These measurements are often sparse and disparate due to unsystematic data collection containing variable methodologies and reporting conventions. To date, …