Physical Sciences and Mathematics Commons^™

Comparative Lineament And Geomorphic Analysis Of Chaotic Terrains And Noctis Labyrinthus, Mars, Sarah A. Walton

Electronic Theses and Dissertations

Noctis Labyrinthus (NL) is an extensional trough network connecting the Tharsis rise and Valles Marineris on Mars. Chaotic terrains are a group of polygonally-fractured surface features commonly associated with subsidence due to rapid fluid loss within the subsurface. Polygonal surface patterns are seen at both sites, where geometric topographic highs are bounded by low troughs. Lineaments, topography, and geomorphology of NL and chaotic terrains were analyzed to determine tectonics and fluid influence in the formation and evolution of both sites. NL shows preferential fracture patterns associated with regional extension. Lineaments within chaotic terrains do not show cumulative preferential trends but …

Quantifying Current Soil Brine Contamination Within The Smackover Oil Field In Arkansas Using Multispectral Digital Imagery, Victoria Williams

Electronic Theses and Dissertations

A remote sensing study was performed to quantify current soil brine contamination across the historic Smackover Oil Field in south-central Arkansas, United States. The oil field was established in 1922 and was not subject to the future waste regulations created by the Arkansas Oil and Gas Commission. Brine is a waste product of oil manufacturing which contains water with high salt levels. The storage and transport of brine in the oil field created landscape scarring across the study area.

Landsat 9 multispectral digital imagery was utilized to create supervised classification maps based on earthen pits and creek scarring across the …

A History Of Complex Simple Lie Algebras, Avrila Frazier

Electronic Theses and Dissertations

In 1869, prompted by his work in differential equations, Sophus Lie wondered about categorizing what he called “closed systems of commutative transformations,” while around the same time, Wilhelm Killing’s work on non-Euclidean geometry encountered related topics. As mathematicians recognized this as a division of abstract algebra, the area became known as “continuous transformation groups," but we now refer to them as Lie groups.

Patterns and structures emerged from their work, such as describing Lie groups in connection with their associated Lie algebras, which can be categorized in many important ways. In this paper, we focus on Lie algebras over the …

Effectiveness Of 2016 Watershed Protection Plan On Bacteria And Nutrient Concentration Loads In The Attoyac Bayou Watershed, Jack Henson

Electronic Theses and Dissertations

In 2004, bacteria and nutrient sampling on the Attoyac Bayou Watershed discovered elevated concentrations of E. coli on five of the main channels key tributary streams. The Attoyac Bayou was then listed on the Texas 303d list of impaired waterbodies and further research was conducted to identify the main sources of contamination in the waterbody. In 2016, the Attoyac Bayou Watershed Plan (WPP) was developed to implement best management practices (BMPs) that would decrease bacteria and nutrient concentrations in the watershed. Educational outreach programs, on-site-sewage facility repair, and livestock management were some of the strategies suggested by the protection plan …

Reservoir Characterization Of The Utica Shale Play Using Well Log Data In Columbiana, Ohio, Tyler L. West

Electronic Theses and Dissertations

The Ordovician Utica shale play is rapidly developing throughout the Appalachian Basin. The play is a mixed carbonate-siliciclastic system that grades from primarily carbonates at its base in the Lexington/Trenton limestones into primarily shale within the Utica shale. As of January 2021, it is the third highest-producing dry shale gas play in the contiguous U.S., although it is known to produce wet gas and oil in various parts of the basin. In addition to being an unconventional reservoir, the Utica shale, an informal unit in Ohio where the main fairway is located, is a known source rock for much of …

An Analysis Of All-Cause Mortality On Patients With Sickle Cell Disease And Kidney Disease Using Propensity Score Matching, Adam Garrison

Electronic Theses and Dissertations

In this work, we provide an overview of the Cox proportional hazards model for time to event or survival analysis and the notion of propensity score matching to deal with confounding factors. A full analysis is reported in Chapter 2 concerning mortality for in-center dialysis patients with sickle cell disease to demonstrate the application of a general analysis strategy that has some logistical benefits over more traditional approaches to accounting for confounding variables. We also provide some insight and discussions on the challenges and future research questions that will emerge when trying to implement this strategy as a monitoring tool …

Blockchain Security: Double-Spending Attack And Prevention, William Henry Scott Iii

Electronic Theses and Dissertations

This thesis shows that distributed consensus systems based on proof of work are vulnerable to hashrate-based double-spending attacks due to abuse of majority rule. Through building a private fork of Litecoin and executing a double-spending attack this thesis examines the mechanics and principles behind the attack. This thesis also conducts a survey of preventative measures used to deter double-spending attacks, concluding that a decentralized peer-to-peer network using proof of work is best protected by the addition of an observer system whether internal or external.

Restrictions On Topological Symmetry Groups Of The 3-Rung Möbius Ladder On The Torus, Logan Willhoite

Electronic Theses and Dissertations

In this work, we discuss properties of the 3-rung Möbius ladder embedded on the surface of a torus. We present proofs on restrictions of topological symmetry groups of the Möbius ladder with and without the assumption of preserving orientation. Specifically, we show that Z₂ is the only possible non-trivial orientation-preserving topological symmetry groups, and also that Z₂ and D₂ are the only possible nontrivial topological symmetry groups.

The Future Is Now In Twisted Coil Polymer Actuators (Tcpa), Ryan Ronquillo

Electronic Theses and Dissertations

This thesis aimed to fabricate and test twisted coiled polymer actuators (TCPA) to understand the mechanical and thermal aspects of this artificial muscle fiber. The purpose of this thesis was to find a linear relationship using the LVDT sensor, fabricating TCPA fibers, and interpreting the data. The project tested whether nylon/polymer could be used as a better artificial muscle fiber.

This research accomplished three goals: (1) designing and fabricating a system capable of creating supercoiled muscle fibers consistently, (2) calibrating the Linear Variable Differential Transformer (LVDT) and Core, and (3) analyzing/interpreting the data of the Twisted Coiled Polymer Actuators (TCPA) …

Dolphin Behavioral Responses To Uncrewed Aerial Systems As A Function Of Exposure, Height, And Type, Savannah Damiano

Electronic Theses and Dissertations

Uncrewed aerial systems (UAS) are becoming a standard tool in the study of cetaceans, however, a comparative assessment of animal responses to UAS has not been established to gauge the most effective systems for cetacean study. We utilized Dolphin Quest Bermuda’s eleven bottlenose dolphins as subjects for such an investigation taking place over five weeks in 2022 and five weeks in 2023. The dolphins were evaluated for investigative behavioral responses to six off-the-shelf UAS types and a custom fixed wing system. Each UAS was flown in decreasing height vertically above the main dolphin lagoon to evaluate dolphin behavioral responses in …

Identifying And Analyzing Multi-Star Systems Among Tess Planetary Candidates Using Gaia, Katie E. Bailey

Electronic Theses and Dissertations

Exoplanets represent a young, rapidly advancing subfield of astrophysics where much is still unknown. It is therefore important to analyze trends among their parameters to learn more about these systems. More complexity is added to these systems with the presence of additional stellar companions. To study these complex systems, one can employ programming languages such as Python to parse databases such as those constructed by TESS and Gaia to bridge the gap between exoplanets and stellar companions. Data can then be analyzed for trends in these multi-star exoplanet systems and in juxtaposition to their single-star counterparts. This research was able …

Distribution And Soil Characteristics Associated With The Neches River Rose-Mallow (Hibiscus Dasycalyx), Morgan E. Langlinais

Electronic Theses and Dissertations

The Neches River rose-mallow, Hibiscus dasycalyx, is a rare herbaceous perennial endemic to East Texas. The threatened, obligate wetland species is currently at risk of being lost in the wild due to habitat loss, encroachment of nonnative and native plant species, and hybridization with two other Hibiscus congeners, Hibiscus laevis and Hibiscus moscheutos. Known locations of each of the three Hibiscus species were used to measure select soil characteristics and habitat variables associated with each of the rose-mallows. H. dasycalyx was concluded to be associated with more fertile soils and slightly more canopy coverage than H. laevis and …

Differentiate Metasploit Framework Attacks From Others, Gina Liu Ajero

Electronic Theses and Dissertations

Metasploit Framework is a very popular collection of penetration testing tools. From auxiliaries such as network scanners and mappers to exploits and payloads, Metasploit Framework offers a plethera of apparatuses to implement all the stages of a penetration test. There are two versions: both a free open-source community version and a commercial professional version called Metasploit Pro. The free version, Metasploit Framework, is heavily used by cyber crimininals to carry out illegal activities to gain unauthorized access to targets.

In this paper, I conduct experiments in a virtual environment to discover whether attacks originated from Metasploit Framework are marked with …

Turning Ligands On Their Side: Computational Investigation Into The Binding Of N2o And N2 In Transition Metal Complexes, Cole Donald

Electronic Theses and Dissertations

Common greenhouse gas nitrous oxide (N₂O) is a thermodynamically potent and environmentally benign oxidant, making it a desirable target for metal center activation. Unfortunately, N₂O is a poor ligand for transition metals due to its weak sigma-donating and pi-accepting properties; as a result, few transition metal complexes capable of interacting with N₂O have been found. As the primary source of all nitrogen in organisms, abundant gas dinitrogen (N₂) is a crucially important tiny molecule and an essential part of daily existence. However, due to its inertness, it has limited practical uses in …

Soil Salinity And Sodicity Of Galveston And Pelican Islands, Texas, Rachel Murray

Electronic Theses and Dissertations

Galveston Island, Texas, is frequently affected by hurricanes. In 2008, Hurricane Ike inundated much of the island with seawater, causing elevated soil salinity levels that killed much of the vegetation on the island, including tens of thousands of trees. Residual salinity in soils and groundwater has hampered vegetation re-establishment in some areas.

This project aims to create a map product that displays the current soil salinity and sodicity levels on Galveston and Pelican Islands. The existing USDA Natural Resource Conservation Service (NRCS) Galveston County Soil Survey map units were used as a base for the project. ArcGIS Desktop software was …

Geochemical Characterization Of The Louann Salt, Puma Field, Green Canyon, Gulf Of Mexico Basin – Using Xrf And Xrd, Brian Lesh

Electronic Theses and Dissertations

The Jurassic-aged Louann Salt is an evaporite sequence deposited in the Gulf of Mexico Basin (GOMB). It is an important component of the GOMB petroleum system and influences the facies pattern in overlying strata and the distribution of petroleum stratigraphic traps. The Louann Salt is composed primarily of halite with intercalated anhydrites and silty or sandy-halite intervals, with overall thicknesses in excess of four kilometers (~13,000 feet). Suture zones occur intermittently within the Louann Salt, formed by the collision of allochthonous evaporite layers. The mineralogy and geochemistry of the suture zones are currently understudied and can be hazardous during drilling …

Geochemical Characterization Of The Bone Spring Formation, Delaware Basin, Using Chemostratigraphy And Integrated Petrophysics, David Tonner

Electronic Theses and Dissertations

The Delaware Basin forms part of West Texas's and New Mexico’s famous petroleum-generating Permian Basin. The Bone Spring Formation is a prolific hydrocarbon producer within this basin, creating one of the world’s richest oil shales. This formation has lithological sequences that are characterized by repeating carbonate and siliciclastic intervals of a third-order cycle which can largely be correlated to highstand and lowstand systems tracts, respectively. Lithological complexity and facies change are manifested by debris flows, turbidites, and slumps. In addition to glacio-eustasy, both tectonism and broader Milankovitch cycles have influenced the depositional history. Previous investigations have utilized cores and wireline …

Effects Of Excessive Soil Phosphorus Accumulation On Loblolly Pine (Pinus Taeda L.) Seedlings, Hannah C. Bays

Electronic Theses and Dissertations

Many landowners in East Texas apply poultry litter to pastures as a source of nitrogen (N) for forage crops. After many years of repeated poultry litter application, soils can accumulate extremely high extractable phosphorus (P) concentrations, sometimes over 1000 mg kg^-1 of plant available P. Landowners report the conversion of these pastures to loblolly pine (Pinus taeda L.) plantations is often problematic, with poor seedling survival and abnormal tree growth. This study was conducted to assess the effects of excessive soil phosphorus on loblolly pine seedlings. An outdoor pot study was conducted using bare root seedlings and triple …

C-H On The Oxo Ferryl Wheel: Comparison Of Pyridine And Imidazole-Substituted Ligands For C-H Activation And Functionalization, Elizabeth Milem

Electronic Theses and Dissertations

The selective and efficient transformation of hydrocarbon feedstocks is of high value for industry and research. While Shilov-type organometallic methods have facilitated this goal, systems designed after nature’s use of cheap and abundant iron-based enzymes are desired for wider-scale applications. This work establishes hydrocarbon oxidation efficiency of synthetic pyridine-based ligands (BPMEN, BPMPN) compared to commercially available TPA with in situ generated catalysts. Literature studies of traditionally synthesized BPMEN systems and initial in situ studies offered evidence for enhanced reactivity (TON) as compared to TPA. Expansion to a propyl backbone to produce BPMPN tested the increased chelate ring size’s impact on …

An Application Of Differential Mathematical Modeling Techniques To Study The Ongoing Rabies Epizootic In China, Christopher Turner

Electronic Theses and Dissertations

Rabies remains a global public health issue with a wide variety of neurological symptoms such as confusion, slight paralysis, hypersalivation, and hydrophobia. Rabies is usually fatal once symptoms appear. Many species are reservoirs for rabies, such as foxes, racoons, and wild dogs, which in turn can transmit the disease to humans, leading to complex transmission chains. There is a long latent period of rabies, between 1 to 3 months after infection, which further complicates control efforts. Mathematical modeling is a valuable tool in the study of infectious disease outbreaks and there have been many models applied to rabies outbreaks. However, …

Investigaion Of The Gamma Hurdle Model For A Single Population Mean, Alissa Jacobs

Electronic Theses and Dissertations

A common issue in some statistical inference problems is dealing with a high frequency of zeroes in a sample of data. For many distributions such as the gamma, optimal inference procedures do not allow for zeroes to be present. In practice, however, it is natural to observe real data sets where nonnegative distributions would make sense to model but naturally zeroes will occur. One example of this is in the analysis of cost in insurance claim studies. One common approach to deal with the presence of zeroes is using a hurdle model. Most literary work on hurdle models will focus …

Seasonal Flammability Comparisons Of Native And Exotic Plants In The Post Oak Savannah, Blackland Prairie, And Pineywoods Ecoregions Of Texas, Michael Tiller

Electronic Theses and Dissertations

East Texas’ diverse landscape can present year-round wildfire seasons that can be influenced by seasonal and regional differences in climate and physiography. Greater insight into the fundamental thermal behavior of wildland fuels can aid in fire behavior prediction and development of fire-resistant plant lists. This study focused on estimating seasonal and regional flammability characteristics of five evergreen species: yaupon (Ilex vomitoria), Chinese privet (Ligustrum sinense), greenbrier (Smilax spp.), eastern red cedar (Juniperus virginiana), and escarpment live oak (Quercus fusiformis); and two deciduous species: Chinese tallow (Triadica sebifera) and southern …

Stratigraphic Analysis Of The Capps Limestone In The North Norton Oil Field In Runnels County, Texas, William Thompson

Electronic Theses and Dissertations

The Desmoinesian (Middle Pennsylvanian) Capps Limestone Member of the Mineral Wells Formation is a carbonate reservoir located in North Central Texas. It consists of interbedded limestone, sandstone, and shale units. Much of the Capps Limestone exists in the subsurface of Brown, Coleman, Runnels, Coke, Nolan, and Taylor counties, however, the Capps Limestone outcrops on the surface in Brown, Eastland, and Palo Pinto counties.

The cored interval from Runnels County was deposited in a marginal marine environment during the Middle Pennsylvanian Period. Although the Capps Limestone was first described in the 1890s, there is still much to be discovered about its …

Confidence Interval For The Mean Of A Beta Distribution, Sean Rangel

Electronic Theses and Dissertations

Statistical inference for the mean of a beta distribution has become increasingly popular in various fields of academic research. In this study, we developed a novel statistical model from likelihood-based techniques to evaluate various confidence interval techniques for the mean of a beta distribution. Simulation studies will be implemented to compare the performance of the confidence intervals. In addition to the development and study involving confidence intervals, we will also apply the confidence intervals to real biological data that was gathered by the Department of Biology at Stephen F. Austin State University and provide recommendations on the best practice.

Soil Gypsum Content Analysis Of The Proposed Road Route Extension Of Fm 2185 In The Gypsum Plain, Culberson County, Texas, Chikaodili Ohakawa

Electronic Theses and Dissertations

Soils serve as the underlying substrate on which foundations for most structures are built. The properties of a soil type are therefore an important consideration in building engineered structures. Gypsic soils are problematic for construction of such structures. One of the main problems with gypsic soils is dissolution. Gypsum (CaSO₄·2H₂O) in soils dissolves easily creating voids which can be detrimental to the integrity of engineering structures. To mitigate this, it is important to determine the amount of gypsum present in soils, before construction is initiated.

In this study, three methods were employed in the determination of …

A Practical Extension To The Ab/Ba Design, My T.A Nguyen

Electronic Theses and Dissertations

In this work, we take a close look at a general extension to the traditional AB/BA
crossover design that is commonly used in clinical trials to determine the effectiveness
of new candidate drugs. While the traditional crossover design requires each patient
in the study to be measured on both treatment A and treatment B, we consider the
possibility of additional measurements being available on each patient. This produces
designs such as the AABB/BBAA design which has been used in previous studies.
A general test statistic will be derived to test for treatment effects as well as its
corresponding power function …

Detailed Structural And Stratigraphic Analysis Of The Salt-Sediment Interactions On Top Of The Wheeler Dome Salt Tongue, Mississippi Canyon Area, Gulf Of Mexico, Ryan Jaska

Electronic Theses and Dissertations

The Mississippi Canyon is in the northeastern part of the Gulf of Mexico, south of the state of Mississippi. In this area, there are many different salt structures present including salt canopies, diapirs, and salt pillows. The Callovian aged Louann Salt covers this area and is the cause of many of the salt structures and structures of the overlying formations seen in Gulf of Mexico today. Salt is mobile when subjected to stress from overlying sediment and gravity. Stress will force the salt to not only move upward, but to also move down slope deeper into adjacent basins through the …

Development Of Standard Operating Procedure With Modified Method To Quantify Benzene And Other Volatile Organic Compounds In Air Samples Using Gas Chromatography, Heather Hall

Electronic Theses and Dissertations

Stephen F. Austin State University (SFASU) Department of Environmental Science has recently invested in a gas chromatograph which can be used to analyze air samples for volatile organic compounds (VOCs) such as benzene, toluene, ethylbenzene, and xylenes (BTEX). The goal of this project was to develop a standard operating procedure (SOP) and modify the current method for the detection of VOCs associated with oil and gas drilling activity to accommodate the equipment and capabilities of SFASU Environmental Assessment Lab. This study aims to provide the framework for future research in air quality monitoring in the Eagle Ford Shale area. An …

The Effects Of Prescribed Burning On Soil Water Infiltration Rates And Other Select Soil Physical And Chemical Properties In East Texas, Cassady Pennington Dunson, Brian P. Oswald, Kenneth Farrish, Tyson Hart

Electronic Theses and Dissertations

This study focused on whether prescribed burning affects soil physical and chemical properties, especially water infiltration, in Western Gulf Coast forests. Soil water infiltration rates were measured 1) pre-burn (before the fire), 2) post-burn (one month after the fire), and 3) at vegetation green-up (three months after the fire). Soil samples were also collected to determine the effects of prescribed burning on soil pH, bulk density, particle density, pore space, soil strength, O-horizon weight and depth (organic matter), water stable aggregates, and soil fertility. This project was conducted on two different burn intervals. The National Forests and Grasslands of Texas …

Prediction Intervals: The Effects And Identification Of Sparse Regions For Nonparametric Regression Methods, Jackson Faires

Electronic Theses and Dissertations

In this work, we provide an overview of different nonparametric methods for prediction interval estimation and investigate how well they perform when making predictions in sparse regions of the predictor space. This sparsity is an extension to the more common concept of extrapolation in linear regression settings. Using simulation studies, we show that coverage probabilities using prediction intervals from quantile k-nearest neighbors and quantile random forest can be biased to low or too high from the nominal level under various situations of sparsity. We also introduce a test that can be used to see if a new data point lies …