Digital Commons Network^™

Historic Log Buildings As Archives Of Past Forest Ecology, Kristen K. De Graauw

Graduate Theses, Dissertations, and Problem Reports (ETD)

This dissertation is composed of three separate but related manuscripts with the common theme of using historic log buildings from the central Appalachian Mountain region of eastern North America as ecological archives. In Chapter 1, I explore the biases, limitations, and ecological applications of tree-ring data from historic log buildings. European immigrants selected trees from a forested stand based on species, log sizes, and construction locations. Despite this selection bias, ecological information can be gleaned from historic log buildings, which offer a complementary record of past forest ecology and represent a site type that is not often associated with old-growth …

X-Ray Fluorescence Applications In Mudrock Characterization: Investigations Into Middle Devonian Stratigraphy, Appalachian Basin, Usa, Keithan Garrett Martin

Graduate Theses, Dissertations, and Problem Reports (ETD)

Mudrocks are characterized by nanometer-scale pore sizes and nano-darcy permeability, which plays a significant role in hydrocarbon flow during production. Resulting from these characteristics, mudrocks were exclusively considered a source rock, which charged overlying, more porous mediums. Hydraulic fracturing, a technology used to create artificial fractures to liberate hydrocarbons from the reservoir, enabled natural gas to be produced from mudrock reservoirs economically. Over the last fifteen years, this technology motivated research efforts to understand reservoir characteristics of mudrock. These investigations significantly improved our knowledge of mudrock systems, but have also highlighted key areas that are undeveloped and/or where conflicting hypotheses …

Resilient Stochastic Control Strategies In Cyber-Physical Microgrids, Mohammad Reza Khalghani

Graduate Theses, Dissertations, and Problem Reports (ETD)

Microgrids are the integration of a large number of distributed energy resources in a decentralized way such that the energy supply reliability and resiliency are enhanced against natural disasters, physical and cyber disruptions. This dissertation addresses three main challenges for microgrid operation and management:

1) According to fast growing number of Electric Vehicles (EV) deployment, their impacts on microgrids resulted from their uncertain behaviors are new concerns for the microgrid operators. These concerns can be EV charging and discharging schedule and locations of EV parking-lots in the system which are considered and solved using stochastic modeling and optimization algorithms based …

Peatlands And Histosols In Canaan Valley National Wildlife Refuge, West Virginia, Mitzy Leigh Schaney

Graduate Theses, Dissertations, and Problem Reports (ETD)

Canaan Valley in West Virginia contains a greater area of peatlands than any other locality in the mid-Atlantic Highlands. Extensive fieldwork focused on peat stratigraphy and pedology, combined with high-resolution radiocarbon dating, was used to evaluate five peatlands within Canaan Valley National Wildlife Refuge (CVNWR) in the central Appalachian Mountains. One hundred soil cores were profiled and described, 30 with laboratory data, including 52 radiocarbon dates. Calibrated basal peat dates among the five mapped peatlands indicate a late Pleistocene timeframe for the onset of peat genesis, ranging from ~18,600 to ~15,200 cal yr BP. The dates for peat initiation are …

Empirical Studies Related To Open Questions Regarding Geomagnetic Storms, Bruce Patrick Tepke

Graduate Theses, Dissertations, and Problem Reports (ETD)

Earth’s magnetosphere is subject to disturbances, as evidenced by variations of the geomagnetic field in space and on the ground. It is generally understood that most such disturbances are controlled by variations in the solar wind, with interplanetary magnetic field orientations directed southward opposite to Earth’s dipole magnetic axis being most conducive to energy transfers into the magnetosphere, thus resulting in more disturbed intervals. However, the exact functional form for solar wind driving of the magnetosphere has been widely studied, with proposed functional forms varying from the simple half-wave electric rectifier to expressions with a much more complicated dependence upon …

Service Dogs For Veterans With Ptsd: Taxonomy, Work Stress Reduction, And Matching, Lindsay Parenti

Graduate Theses, Dissertations, and Problem Reports (ETD)

Research suggests that many veterans with post-traumatic stress disorder (PTSD) struggle with reintegration (Sayer et al., 2010), but are unlikely to seek help or complete treatment (Schottenbauer et al., 2008). To make matters worse, available treatment options are often time consuming, challenging, and/or associated with negative side effects (Carafano & Hutchinson, 2017). Using animals as a treatment modality for veterans with PTSD is an emerging topic of interest and has shown promise (Owen, et al., 2016; Richie et al., 2016). However, several factors have hindered the advancement of this field. Obstacles include a lack of standard terminology and classification system, …

Three Essays On Applied Semiparametric Methods, Qinling Lu

Graduate Theses, Dissertations, and Problem Reports (ETD)

The first chapter studies a varying coefficient panel data model with different smoothing variables and fixed effects using a two-step estimation approach. The first-step pilot estimator is constructed by ap- approximating the varying coefficients with B-spline functions. The pilot estimator is then used to perform a one-step backfitting to obtain the second-step efficient estimator with kernel local linear estimation. The second-step estimator is efficient in the sense of being equivalent to a procedure knowing the other components of the varying coefficient. The asymptotic properties of both the pilot and efficient estimators are obtained. A Monte Carlo simulation indicates that the …

Object-Based Supervised Machine Learning Regional-Scale Land-Cover Classification Using High Resolution Remotely Sensed Data, Christopher A. Ramezan

Graduate Theses, Dissertations, and Problem Reports (ETD)

High spatial resolution (HR) (1m – 5m) remotely sensed data in conjunction with supervised machine learning classification are commonly used to construct land-cover classifications. Despite the increasing availability of HR data, most studies investigating HR remotely sensed data and associated classification methods employ relatively small study areas. This work therefore drew on a 2,609 km2, regional-scale study in northeastern West Virginia, USA, to investigates a number of core aspects of HR land-cover supervised classification using machine learning. Issues explored include training sample selection, cross-validation parameter tuning, the choice of machine learning algorithm, training sample set size, and feature selection. A …

Experimental And Modeling Investigation Of The Oh-Initiated Oxidation Of Semi-Solid And Aqueous Saccharide Aerosols, Hanyu Fan

Graduate Theses, Dissertations, and Problem Reports (ETD)

My research focuses on investigating the impact of moisture-induced and oligomer-induced viscosity changes on OH-initiated oxidation of semi-solid aerosols,and the role of gas-liquid interfaces in regulating aqueous aerosol chemistry. Saccharides, which are a major constituent of aqueous atmospheric aerosols, are chosen as model molecules to form highly oxygenated organic aerosols. The experiments are performed using an atmospheric pressure flow-tube reactor with both online VUV-AMS (Vacuum-Ultraviolet Aerosol Mass Spectrometer) and offline GC-MS analysis techniques. The decay rates of saccharide are determined by measuring the loss signal of saccharide in the particle phase as a function of OH exposure (time-integrated total concentration …

Discerning The Diets Of Sweep-Feeding Eurypterids Through Analyses Of Mesh-Modified Appendage Armature, Emily Samantha Hughes

Graduate Theses, Dissertations, and Problem Reports (ETD)

Eurypterids were a group of aquatic chelicerates that lived throughout most of the Paleozoic. While swimming eurypterids are generally considered to be active predators, the benthic stylonurine eurypterids appear to have had a mode of life similar to modern horseshoe crabs with the exception of two clades, the Stylonuroidea and the Mycteropoidea, both of which independently evolved modifications for sweep-feeding on their anterior appendages. Among extant suspension feeders, it has been shown that there is a linear correlation between the average spacing of feeding structures and prey sizes. This relationship was extrapolated to the sweep-feeding stylonuroid and mycteropoid eurypterids in …

An Assessment Of The Methods Used To Teach Content Skill Sets Required For The Introduction To Agriculture, Food, And Natural Resource Course, Lee I. Wright

Graduate Theses, Dissertations, and Problem Reports (ETD)

Numerous studies have shown that students learn best when theory is applied to hands-on experiences. Traditionally, vocational agriculture, which evolved into agricultural education, has incorporated hands-on learning. For example, students typically raise livestock and crops as part of supervised agricultural experiences; learn to use chain saws, tractors, hay rakes, balers and other equipment found on farms; and basic metal working skills. They also sample soil and water to test for mineral levels and types of pollution that might affect agricultural practices. The purpose of this study, which incorporates a survey of agricultural education teachers in West Virginia, is to determine …

Edge Colorings Of Graphs On Surfaces And Star Edge Colorings Of Sparse Graphs, Katherine M. Horacek

Graduate Theses, Dissertations, and Problem Reports (ETD)

In my dissertation, I present results on two types of edge coloring problems for graphs.

For each surface Σ, we define ∆(Σ) = max{∆(G)| G is a class two graph with maximum degree ∆(G) that can be embedded in Σ}. Hence Vizing’s Planar Graph Conjecture can be restated as ∆(Σ) = 5 if Σ is a sphere. For a surface Σ with characteristic χ(Σ) ≤ 0, it is known ∆(Σ) ≥ H(χ(Σ))−1, where H(χ(Σ)) is the Heawood number of the surface, and if the Euler char- acteristic χ(Σ) ∈ {−7, −6, . . . , −1, 0}, ∆(Σ) is already …

An Assessment Of Farmer Participation In The United States Department Of Agriculture, Natural Resources Conservation Services’ Conservation Technical Assistance Program In West Virginia, Matt D. Oliver

Graduate Theses, Dissertations, and Problem Reports (ETD)

Food and fiber production on America’s farmlands have a major influence on the environment, therefore, soil and water conservation practices are critical. NRCS has provided no-fee technical assistance for nearly 100 years through the Conservation Technical Assistance (CTA) program. The CTA program is essential because it provides technical knowledge directly to farmers for planning and implementing conservation practices that are proven to benefit environmental health and on-farm production. CTA program funds support NRCS staff and training and are thereby the local service delivery vehicle for all NRCS programs. However, in recent years, funding for CTA has remained relatively constant while …

Non-Target Analyses Of Novel Psychoactive Substances; Inherent Variation In Gcms Relative Abundances And Gas Phase Hydrogen Deuterium Exchange Isomer Discrimination, Kristin Michelle Kelly

Graduate Theses, Dissertations, and Problem Reports (ETD)

Novel psychoactive substances (NPSs) are synthetically derived compounds designed to mimic the effects of other illicit drugs. An endless cycle of NPSs continually reach the drug market due to limitations in drug legislation creating two problems: (1) non-availability of standards and (2) multiple isobars indistinguishable even to high resolution mass spectrometry. Gas chromatography-mass spectrometry (GCMS) is the most common instrument used for compound identification in non-targeted seized drug analysis. Compound identification using this technique relies on mass spectra where the percent relative abundances (%RAs) of all m/z values are compared manually or searched against a library database. Lacking standards, laboratories …

Evaluation Of Ufp Number Concentrations Near A Natural Gas Transmissions Station, John M. Thornsbury

Graduate Theses, Dissertations, and Problem Reports (ETD)

Identifying UFP number concentrations near a natural gas compressor station is key to understanding ambient exposures associated with the transmission station. Developing an atmospheric survey to characterize these concentrations was key in understanding ambient exposures. The aims of this study are to compare and contrast number concentrations taken in a hollow, near the transmission station to those of the background. From this, it would be possible to identify whether or not the compressor station was a contributing factor to peaks and spikes in number concentrations.

This study begins with a review of what UFPs are, how they react in different …

The Impact Of Hii Regions On The Interstellar Medium Of Our Galaxy, Matteo Luisi

Graduate Theses, Dissertations, and Problem Reports (ETD)

The interstellar medium (ISM) of our Galaxy contains low-density diffuse ionized gas known as the warm ionized medium (WIM). O- and B-type stars emit large amounts of ionizing radiation and it is believed that a fraction of this radiation escapes from their fully ionized HII regions and into the ISM where it is responsible for maintaining the ionization of the WIM. Here we aim to better understand how the radiation produced by OB stars is able to leak from the HII regions, how the radiation field changes during this process, and how the radiation affects the ambient ISM. Using Green …

Experimental Measurement Of Dielectric Properties Of Powdery Materials Using A Coaxial Transmission Line, Robert Tempke

Graduate Theses, Dissertations, and Problem Reports (ETD)

This study proposes a standard methodology for coaxial dielectric property measurements of powdery materials (1-10GHz) using a coaxial transmission line. Four powdery materials with dielectric constants ranging from 3.5 to 70 (SiO2, Al2O3, CeO2, and TiO2) were experimentally investigated at varying volume loading fractions in a paraffin mixture. A statistically significant number of paraffin heterogeneous-mixtures was synthesized for all dielectric powders. The dielectric properties of the constitutive materials were determined using appropriate mixture equations. The sensitivity of the equations dielectric prediction to volume loading is discussed with guidance on selecting the best mixing equation. It was determined that low volume …

Impacts Of Climate Change On Water Balance Components In The Central Appalachian Mountains, Usa, Brandi Anne Gaertner

Graduate Theses, Dissertations, and Problem Reports (ETD)

This research investigated the impact of climate and land cover on water balance components including evapotranspiration and runoff in the mountainous central Appalachian region of the United States. The first studyanalyzed trends in climatologic, hydrologic, and growing season length variables, identified the important variables effecting growing season length changes, and evaluated the influence of a lengthened growing season on increasing evapotranspiration trends. The results showed that growing season length has increased, on average, by ~22 days and evapotranspiration has increased ~12 mm. The second study quantified long-term historical and future climate trends, evaluated water balance sensitivity to change, and quantified …

Structural Style And Stratigraphic Architecture Of The Northeastern Brooks Range, Alaska, Benjamin G. Johnson

Graduate Theses, Dissertations, and Problem Reports (ETD)

The Arctic Alaska–Chukotka microplate is a large Mesozoic–Cenozoic composite terrane that resides at the northern limit of the North American Cordillera. Although its Mesozoic origins are assuredly linked to the opening of the Amerasian Basin of the Arctic Ocean, its Paleozoic origins can be linked to at least three separate paleocontinents, including northern Laurentia, Baltica, and Siberia. Across the Arctic Alaska portion of the microplate, an internal, mid-Paleozoic suture zone presumably separates rocks of the North Slope subterrane (Laurentian affinity) from a collection of smaller subterranes in the southern Brooks Range and Seward Peninsula (Baltic affinity).

The mountains of the …

Stream Salamander And Benthic Macroinvertebrate Community Responses To Imidacloprid Exposure, Sara M. Crayton

Graduate Theses, Dissertations, and Problem Reports (ETD)

The insecticide imidacloprid is widely used to mitigate hemlock (Tsuga spp.) mortality resulting from the invasive hemlock woolly adelgid (HWA), but evidence suggests that

imidacloprid can have negative effects on adjacent stream systems. Imidacloprid exposure causes physiological changes, bioaccumulation, and reduced survival in anurans, and induces physiological impairment and reduced survival in benthic macroinvertebrates. In this thesis, we assessed whether HWA treatments using imidacloprid affect stream salamander abundances and benthic macroinvertebrate community composition. We also investigated whether imidacloprid or its metabolites bioaccumulate in benthic macroinvertebrates or salamanders and cause sublethal effects. We conducted this study in two National Park …

Evaluation Of X-Ray Spectroscopic Techniques For Determining Temperature And Density In Plasmas, Theodore Scott Lane

Graduate Theses, Dissertations, and Problem Reports (ETD)

Temperature and density measurements of plasmas are important for understanding various phenomena. For example, equations of state, most scaling arguments for Inertial Confinement Fusion and laboratory astrophysics all rely upon accurate knowledge of temperature and density. Spectroscopy is a non-invasive technique to measure these quantities. In this work we establish a new spectroscopic technique by using it to determine temperature. We also compare and contrast the capability of two codes, PrismSPECT and ATOMIC, to infer electron density from experimentally acquired spectra via Stark broadening.

We compare and contrast the capability of isoelectronic line ratios and inter-stage line ratios in an …

Soil Health Assessment In Reclaimed Mine Soils, Katie Danielle Stutler

Graduate Theses, Dissertations, and Problem Reports (ETD)

West Virginia is one of the top coal-producing states in the nation, which has resulted in over 500,000 acres of highly disturbed, anthropogenic mine soils caused by surface mining. Mine soils are often rocky and contain low organic matter content, low plant-available nutrients, and toxic metals, which could result in poor soil health and low productivity. Soil health has been defined as the continued capacity of soil to function as a living ecosystem that sustains plants, animals, and humans. It is assumed that with time since reclamation, mine soil properties and related functions may change, and soil health will improve …

Computational Design Of Staged Pressurized Oxy-Coal Combustion, Gideon Ozioma Udochukwu

Graduate Theses, Dissertations, and Problem Reports (ETD)

Staged pressurized oxy-coal combustion (SPOC) is nowadays a promising technology to be used for low-cost, low-emission, high-efficiency power generation. The objective of this thesis is to compliment the experiments ongoing at the Washington University, St. Louis (WUSTL) by means of numerical simulations, thereby providing better understanding of the fluid flow, turbulence, combustion characteristics, particle dynamics and heat transfer. Carbon dioxide (CO2) is injected alongside the coal, for its carriage. A small amount of methane (CH4) is also injected alongside the coal to maintain a steady flame. The simulations are performed for a 3D geometry with the following energy source distribution: …

Modeling Movement Of Criminals Through Burglary Scenes, Veronica L. Herrmann

Graduate Theses, Dissertations, and Problem Reports (ETD)

Physical evidence plays a large role in the criminal justice system and in crime scene reconstruction. The purpose of evidence is to assist in connecting a person or persons to an incidence, which helps crime scene investigators in reconstructing the events that occurred at the crime scene. This concept is mainly based off Locard's Exchange Principle, which states that there is always an association between an offender and evidence. However, without patent evidence to lead the investigators to a possible route at the scene, determining the movements taken during the commission at a scene is needed.

Engineers have used simulations …

Identification Of Burnt Smokeless Gunpowders Through Physical Characteristics, Cameron Taylor Hartwig

Graduate Theses, Dissertations, and Problem Reports (ETD)

Firearms are one of the most commonly used weapons by violent criminals throughout the United States. In crimes involving the discharge of a firearm, residues from the combustion products are deposited on the shooter and in the firing direction. Some of the residues left behind are unburnt and partially burnt particles of the propellant. The most common propellant used in modern firearms is smokeless powder. The identification of particles as smokeless powder and the determination of the brand of the powder are two ways a forensic examiner may be able to utilize smokeless powder evidence. The determination of the brand …

Implications Of Sampling Methods On Geospatial Mapping Of Methane Sources, Dakota Wesley Oliver

Graduate Theses, Dissertations, and Problem Reports (ETD)

Natural gas is deployed as an alternative fuel due to its cost and post-combustion emissions. However, methane, the main component of natural gas, is a greenhouse gas with a global warming potential (GWP) of at least 28 over 100 years. Currently, natural gas and petroleum systems are the highest emitters of methane to the atmosphere. Using conventional methods, the detection of natural gas leaks is time consuming. Currently, natural gas production sites deploy the Environmental Protection Agency’s (EPA) Method 21 or optical gas imaging (OGI) for methane leak detection. Both methods require access to the natural gas site along with …

Adult Atlantic Sturgeon Population Dynamics In The York River, Virginia, Jason E. Kahn

Graduate Theses, Dissertations, and Problem Reports (ETD)

Sturgeon first appear in the fossil record in the Triassic Period just over 200 million years ago and are among the most primitive of the bony fishes. Despite their large size and historic presence along the East Coast, Atlantic sturgeon were not targeted for their meat and caviar as a commercial fishery until 1880. By 1905 they had declined to less than one percent of their pre-fishing abundance but the fishery continued. Prior to 1980, there had been very little research on Atlantic sturgeon, primarily limited to documenting landing location and poundage, maximum longevity, or weight of eggs per fish. …

In Situ Measurement Of Fatigue Induced Crack Growth In Inconel 718 Using Direct Current Potential Drop Method, Joel C. Lindsay

Graduate Theses, Dissertations, and Problem Reports (ETD)

With recent advances in air breathable engines comes more extreme temperature environments that engine components must tolerate. During the design of these engines, it is necessary to understand how material fatigue failures occur at these new, higher operating temperatures. In providing understanding, the following fundamental study focuses on the statistical nature of crack jumps (changes in crack length over time) during fatigue in a polycrystalline nickel-based superalloy, Inconel 718 (IN718). In situ measurement of the crack length at several loading conditions were conducted using a direct current potential drop (DCPD) measurement method. Experimental data was collected at six different fatigue …

Automatic Detection Of Insecure Codes In Stack Overflow, Shifu Hou

Graduate Theses, Dissertations, and Problem Reports (ETD)

As the popularity of modern social coding paradigm such as Stack Overflow grows, its potential security risks increase as well (e.g., insecure codes could be easily embedded and distributed). To address this largely overlooked issue, we bring a new insight to exploit social coding properties in addition to code content for automatic detection of insecure code snippets in Stack Overflow. To determine if the given code snippets are insecure, we not only analyze the code content, but also utilize various kinds of relations among users, badges, questions, answers, code snippets and keywords in Stack Overflow. To model the rich semantic …

Carbon Deposition On Ni/Ysz Anode Sofc For Direct Methane Steam Reforming, Haiyang Li

Graduate Theses, Dissertations, and Problem Reports (ETD)

Solid Oxide Fuel Cells (SOFCs) are electrochemical devices that produce electricity directly from oxidizing fuels. Compared to direct combustion of hydrogen to generate power, it has a big advantage in aspects from efficiency and safety when using hydrogen as the fuel of SOFCs. Hydrocarbon reforming is one of the conventional methods to convert natural gas into hydrogen. While considering the difficulty in storage and transportation of hydrogen, we can utilize the supporting materials on the anode side of SOFCs as catalyst to generate hydrogen via hydrocarbon reforming process and pour the hydrogen as fuel into the SOFC system. Ni/YSZ is …