Physical Sciences and Mathematics Commons^™

Valorization Of Xylan In Agroforestry Waste Streams, Harrison Appiah

Graduate Theses, Dissertations, and Problem Reports

Valorization of Xylan in Agroforestry Waste Streams.

Harrison Appiah

Microwave-assisted deep eutectic solvent and gamma-valerolactone metallic chloride catalyzed conversion of xylan to furfural were investigated using a 2x3 factorial experimental design at two levels of percent microwave power, reaction time, and catalyst concentration. The levels of each factor studied were (20%, 60% microwave power, 2, 4 minutes, and 10, 20mg) respectively. The effect of three metallic chloride catalysts (LiCl, FeCl3.6H20, CuCl2) on the conversion of xylan to furfural was also investigated. The gamma-valerolactone-ferric chloride sent system exhibited the highest mean yield of furfural (56.50%). The next highest furfural yield of …

Soil Response Of Helicopter Liming In The Monongahela National Forest, Jarrett Douglas Fowler

Graduate Theses, Dissertations, and Problem Reports

Soils in the Monongahela National Forest (MNF) are acidic due to sandstone parent material, acid deposition, uptake of base cations by vegetation, and release of organic acids by organic matter (OM) decomposition. Increases in soil acidity have caused declines in forest health and changed species composition and nutrient status. Liming can neutralize soil acidity, but no large-scale liming projects have been done on acid forest soils in the USA. In anticipation of acquiring funding for a proposed liming project in the MNF, in 2007 and 2009 10 sites were selected to sample and analyze soils before lime was applied. In …

Using Molecular Dynamics To Characterize The Relationship Between Membrane Components And Dynamics And Supramolecular Organization Of Membrane Proteins, Eric Sefah

Graduate Theses, Dissertations, and Problem Reports

Molecular dynamics (MD) simulations have gained impetus as a technique for elucidating structural and dynamical information about membrane proteins (MP). In particular, coarse-grained (CG) MD simulations have provided valuable information about the relationship between membrane components and supramolecular organization of MPs. In this work MD simulations are used to characterize the effects of hopanoids on bacterial membrane dynamics and association in a model protein proteorhodopsin (PR), as well as the role of the extended C-terminus of the human adenosine receptor (A_2AR) on its dimerization. PR is found to dimerize in a manner that is dependent on both the …

Analysis And Classification Of Software Fault-Proneness And Vulnerabilities, Mohammad Jamil Ahmad

Graduate Theses, Dissertations, and Problem Reports

Software bugs are expensive to fix and can lead to catastrophic consequences. Therefore, their analysis and the use of machine learning for prediction are of the utmost importance. Many prediction models have been proposed and different factors affecting the prediction performance have been extensively studied. This work addresses four topics in two areas in software engineering: software fault-proneness prediction and analysis and classification of security-related bug reports. The first topic focuses on the effect of the learning approach (i.e., the way software fault-proneness prediction models are trained and tested) on the performance of software fault-proneness prediction which lacks extensive research …

Regional Correlation And Depositional History Using Well Log And Core Data Of The Middle Devonian Marcellus Poseidon 8m Well, Westmoreland County, Pennsylvania, Usa, Emily R. Jackson

Graduate Theses, Dissertations, and Problem Reports

The Marcellus Shale is the largest natural gas producing formation in the Appalachian basin, and as such, presents a unique opportunity for continued research on an area that is critical to meeting the energy needs of the current society. Although the Marcellus has historically been extensively researched, acquisition of well log and core data from the Marcellus Poseidon 8M well in Westmoreland County, PA, allows for application of a new method of data integration, which was utilized in this project to specifically understand the depositional environment and create a correlation with other study wells throughout the basin. This integration was …

Development Of Vibrating Sharp-Edge Spray Ionization (Vssi) Methods For Mass Spectrometry Analysis And Imaging, Nandhini Ranganathan

Graduate Theses, Dissertations, and Problem Reports

Mass Spectrometry (MS) is one of the widely used tools for chemical detection down to attomole concentrations for certain proteins. Ionization sources are a critical component for MS analysis. One of the major ionization methods is electrospray ionization (ESI), which remains a gold standard for proteins and peptides. ESI uses voltages up to ~4 kV to produce ions from solubilized molecules. Recently, a novel ionization method termed vibrating sharp-edge spray ionization (VSSI) that nebulizes liquids efficiently at the edge of a vibrating glass slide has been reported. The work in this thesis leverages the capabilities of VSSI for continuous flow-based …

Reservoir Characteristics And Lateral Variability Of The Marcellus Formation At The Allegheny Mountain Front, Bruno J. Abersold

Graduate Theses, Dissertations, and Problem Reports

The Marcellus Formation, a large shale gas reservoir located within in the Appalachian basin, produces the energy that fuels the economy across the United States. Well data and rock core for the Coastal 1H well, found in Fayette County, Pennsylvania, provides the basis to understand reservoir characteristics and depositional processes of the Marcellus Formation across the basin. The well is located near along the eastern edge of the productive fairway and adjacent to the Allegheny mountain front. We used characteristics, such as total organic carbon (TOC), geomechanical properties, and lithology, to integrate with ten other available wells across the basin. …

Remediation Of Spatial Skills In First Semester Calculus Using Haptics-Based Applications, Kristen L. Murphy

Graduate Theses, Dissertations, and Problem Reports

Spatial reasoning is required for many topics in undergraduate mathematics as well as other STEM fields. In calculus specifically, there are few interventions that assess students’ spatial skills and provide remediation. Haptic technology is a novel approach to spatial skills remediation due to its unfamiliarity to students and its flexibility with regard to models. The purpose of this dissertation is two-fold: first, to determine what level of spatial abilities students possess upon entering an undergraduate calculus course, and second, to determine whether haptic feedback will enhance an intervention for improving spatial skills.

The dissertation research was a mixed-methods study using …

Unique Biological Applications Of Charge Transfer Dissociation Mass Spectrometry, Halle M. Edwards

Graduate Theses, Dissertations, and Problem Reports

The ever-changing landscape of mass spectrometry is driven by gaps in knowledge, and one of the biggest driving forces is the desire to understand the structure and dynamics of biomolecules in living organisms. New and better methods of tandem mass spectrometry are often at the heart of technological developments. Some fragmentation methods are limited to expensive FTICR instruments, some techniques are limited multiply charged precursors, and others are limited to breaking only the weakest bonds in precursor ions; all of which support the pursuit of new activation methods. Charge transfer dissociation (CTD) addresses some of these concerns by providing structurally …

Using Numerical Relativity To Explore Strong Gravity And Develop Force-Free Electrodynamics Simulation Software With Best-Practice Development, Patrick E. Nelson

Graduate Theses, Dissertations, and Problem Reports

In this dissertation, we explore the effects of extremely strong gravitational and electro- dynamic fields using the techniques of numerical relativity. We use the existing black hole simulation software in the Einstein Toolkit to compute the spin-up of two initially nonspin- ning black holes as they pass by each other in space. The angular momentum is imparted by the tidal interaction between the two black holes, in a parallel to Earth’s tides, as described by classical mechanics, which also transfer angular momentum between the Earth’s rotation and the Moon’s orbit. The largest observed dimensionless spin observed was 0.20 with an …

Improving Characterization Of Small Molecules Using Enhanced Molecular Reaction And Ionization Techniques, Sandra N. Majuta

Graduate Theses, Dissertations, and Problem Reports

Metabolomics is an emerging “omics” field, which is comprised of the study of small molecule metabolites in biological systems. It can be argued that the abundances of metabolites within biological samples, such as tissue and plasma, are indicative of various physiological states. Thus, metabolomics analysis has the potential in the clinical scientific field to be an effective tool for early disease diagnosis as well as for proposing and monitoring new treatments for diseases. However, full characterization of the metabolome complement is often hampered by the wide diversity of metabolites, which also exhibit an extremely large concentration range in biological samples. …

The Impact Of Unsaturated Zone Thickness On The Severity Of Saltwater Intrusion In Coastal Aquifers From Overtopping, Dennis Jesse Carpinello

Graduate Theses, Dissertations, and Problem Reports

Storm-surge inundation and wave overwash, collectively overtopping, causes the land surface to be inundated with seawater, resulting in vertical infiltration of saline waters into underlying coastal aquifers, which can have severe consequences on freshwater resources. Unsaturated zone thickness plays an important role in determining the severity of saltwater contamination resulting from an overtopping event. This study uses numerical modeling to investigate vertical saltwater infiltration and salinization, and the subsequent aquifer recovery to overtopping events for coastal aquifers with different unsaturated zone thicknesses. Groundwater models were developed using the numerical code SUTRA to solve saturated-unsaturated, density-dependent groundwater flow and solute …

Effects Of Multiple Stressors On Aquatic Macroinvertebrate Communities In A Mixed-Land-Use Watershed, Joellen Stivala

Graduate Theses, Dissertations, and Problem Reports

As urbanization continues, there is a need to identify and understand environmental stressors that impact stream condition in mixed-land-use watersheds. This study analyzed four years of aquatic macroinvertebrate community and environmental data collected from ten sites located at the mouths of first-order tributaries and along the main stem creek of a 23-km², mixed-land-use watershed in central Appalachia. The main objectives were to 1) determine stream ecological integrity by analyzing stream macroinvertebrate taxonomic and trait-based composition and 2) assess which of 23 environmental variables explained significant variability in common community composition metrics (WVSCI, GLIMPSS, Biotic Index, % clingers, etc.). …

Effects Of Different Liquid Smoke Treatments On Osmotic Dehydration Of Apple Cubes, Rohit Singh

Graduate Theses, Dissertations, and Problem Reports

Refined Liquid Smoke (RLS) (1%) was incorporated during osmotic dehydration of apple cubes (10 mm each side) to observe its effect on solid gain, water loss, yield, water activity, product quality, and consumer preference. Three different treatments, POD (pure osmotic dehydration, no RLS), LSISS (RLS inside sugar solution) and PTLS (pre-treatment with RLS), were compared in this study. Osmotic dehydration was carried out using 42 °Brix sugar solution, and the fruit to solution ratio was kept at 1:4. The osmotically dehydrated apples were evaluated for soluble solid content (SSC), water loss, and solid gained. After osmotic dehydration, apple cubes were …

Experimental Investigations Of Contact Friction And Transport Properties Of Monolayer And Bilayer Graphene, Prakash Gajurel

Graduate Theses, Dissertations, and Problem Reports

Results obtained from experimental investigations of contact friction in monolayer and bilayers graphene and the related effects on their transport properties are presented here along with their discussion and interpretation. For this purpose, chemical vapor deposited (CVD) graphene samples on SiO₂/Si were prepared. The samples were characterized by atomic force microscopy (AFM), Raman and X-ray photoelectron spectroscopy (XPS). Summaries of the results are given below.

Defects-controlled friction in graphene is of technological importance but the underlying mechanism remains a subject of debate. The new results obtained from the analysis of lateral force microscopy images revealed that the contact …

Investigation Of Ions Accelerated Through Electrostatic Menisci In An Inductively Coupled Plasma, David D. Caron

Graduate Theses, Dissertations, and Problem Reports

Plasmas are used in semiconductor fabrication as they allow for very precise control over processes such as etching and doping. This is achieved by extracting a beam of ions from the plasma to interact with and modify the surface of a silicon wafer. However, conventional fabrication methods are reaching spatial limitations as semiconductor features reach the atomic scale. Therefore, in order to better control the fabrication processes and facilitate the transition to three-dimensional architecture, a greater understanding of ion beam formation is needed. Ion beams are extracted at the boundary between the Debye sheath and an externally applied potential, which …

Review Of Forecasting Univariate Time-Series Data With Application To Water-Energy Nexus Studies & Proposal Of Parallel Hybrid Sarima-Ann Model, Cory Sumner Yarrington

Graduate Theses, Dissertations, and Problem Reports

The necessary materials for most human activities are water and energy. Integrated analysis to accurately forecast water and energy consumption enables the implementation of efficient short and long-term resource management planning as well as expanding policy and research possibilities for the supportive infrastructure. However, the integral relationship between water and energy (water-energy nexus) poses a difficult problem for modeling. The accessibility and physical overlay of data sets related to water-energy nexus is another main issue for a reliable water-energy consumption forecast. The framework of urban metabolism (UM) uses several types of data to build a global view and highlight issues …

Recovery Of Phosphorus From Florida Phosphatic Waste Clay, Amir Eskanlou

Graduate Theses, Dissertations, and Problem Reports

This MS thesis examines the recovery of phosphorus (P) from Florida waste clay (WC). A comprehensive literature review revealed that: (i)-The most important values being lost to WC are P and rare earth elements (REEs). For the recovery of these values from WC, two crucial attempts are the removal of extremely fine-sized clays, followed by the recovery of phosphate content, which can pave the path for the recovery of REEs; (ii)-Any scientific/ technological solution should, at the same time, be economically and environmentally attractive to the industry. As such, moving from mostly chemical separation processes to the primarily physical/ physicochemical …

Grouping Algorithms For Informative Array Testing In Disease Surveillance, David Sokolov

Graduate Theses, Dissertations, and Problem Reports

In order to maintain normal operations and prevent unnecessary morbidity and mortality during times of disease outbreak, institutions find a need to conduct frequent and widespread testing of their constituents, often under significantly limited testing resource constraints. Faced with the challenge of how best to allo- cate these limited resources to maximum effect, institutions are increasingly turning to group (or “pooled”) testing, which involves testing strategically-chosen groups of patient samples rather than individual samples, producing significant testing resource savings under certain regimes of disease prevalence. While group test- ing can be conducted without any a priori knowledge of individual disease …

Photochemical Motion Control Of Belousov-Zhabotinsky Droplets And Turbulence-Like Patterns In The Aluminum Hydroxide Precipitation System, Syed Jazli Syed Jamaluddin

Graduate Theses, Dissertations, and Problem Reports

A Belousov-Zhabotinsky (BZ) droplet that is immersed in an oil-phase can self-propel due to a surface tension gradient that exists on the droplet surface. The surface tension gradient is created as a result of the reactions that occur within and on the surface of the BZ droplet. By affecting the rates of these reactions, the BZ droplet direction can be controlled. In our experiments, we tune the reactions that occur within and on the BZ droplet surface by imposing a light intensity gradient on the droplet. We analyzed the BZ droplet motion and demonstrated that we can control the droplet …

Gas Phase Reactions Of Cyclopentadiene With Ch And Oh Radicals, Kacee Lynn Caster

Graduate Theses, Dissertations, and Problem Reports

The formation of polycyclic aromatic hydrocarbons (PAHs) and carbon-based nanoparticles in combustion environments is driven by the pyrolysis and oxidation of abundant fuel molecules. The subsequent growth of these pyrolytic byproducts is then propagated by reactions with small free radical species like OH, CH, O atoms, and C₂H. Cyclopentadiene (C₅H₆) is a significant five-member combustion intermediate that has been detected in many high temperature reactions, such as in the pyrolysis of jet fuels like JP-10. Experimental and theoretical investigations in the reactions of cyclopentadiene with these small free radical species are necessary towards understanding …

Development Of Eccentric Black Hole Binary Searches In The Ligo And Pta Regimes, Belinda D. Cheeseboro

Graduate Theses, Dissertations, and Problem Reports

In the past several years, a plethora of gravitational wave events have been detected leading to better understanding of binary black holes, binary neutron stars, and neutron star black hole binaries. All of these transient detections have helped us better understand the dynamics of these systems as well as the populations of these objects, but each of these sources was detected with models that neglected eccentricity. Eccentricity is one of several potential markers for determining the formation of binary systems. Detecting gravitational waves from eccentric sources can better our understanding of such systems and help constrain theories about their formation. …

Identification And Classification Of Radio Pulsar Signals Using Machine Learning, Di Pang

Graduate Theses, Dissertations, and Problem Reports

Automated single-pulse search approaches are necessary as ever-increasing amount of observed data makes the manual inspection impractical. Detecting radio pulsars using single-pulse searches, however, is a challenging problem for machine learning because pul- sar signals often vary significantly in brightness, width, and shape and are only detected in a small fraction of observed data.

The research work presented in this dissertation is focused on development of ma- chine learning algorithms and approaches for single-pulse searches in the time domain. Specifically, (1) We developed a two-stage single-pulse search approach, named Single- Pulse Event Group IDentification (SPEGID), which automatically identifies and clas- …

Online Ultra-High Performance Liquid Chromatography-Charge Transfer Dissociation-Mass Spectrometry (Uhplc-Ctd-Ms) Of Complex Mixtures Of Oligosaccharides, Praneeth M. Mendis

Graduate Theses, Dissertations, and Problem Reports

Abstract

Online Ultra-High Performance Liquid Chromatography-Charge Transfer Dissociation-Mass Spectrometry (UHPLC-CTD-MS) of Complex Mixtures of Oligosaccharides

Praneeth M. Mendis

Complex carbohydrates make up more than half the biomass on earth, and they are crucial to a wide range of processes in living organisms. When polysaccharides and glycans are enzymatically digested into manageable units called oligosaccharides, they typically consist of 2-20 linear or branched sugar units. The detailed structural analysis of oligosaccharides assists in the identification of structural and chemical properties of the polymers from which they derive. Tandem mass spectrometry (MS/MS) is a key technique used in oligosaccharides structural characterization. Within …

Development Of Synthetic Coal Char Simulant For Microwave Conversion Studies: A Computationally-Driven Approach, Kevin A. Hager

Graduate Theses, Dissertations, and Problem Reports

Recent experimental demonstration of new reaction windows for coal char/methane reactions that are less energy-intensive, provides innovation for modular reactors. However, the correlation of the exact mechanism for the enhancement of these reaction windows is not certain. This study investigates the simplification of these experimental studies by developing a well-characterized coal char simulant. The approach involves using a computational approach to screen macroscopic composition to replicate the dielectric and compositional response of actual char. This study is focused on PRB coal char. A discrete element method (DEM) technique was used to simulate the packing of coal chars to give the …

Understanding Visitor Use At Florida Keys National Marine Sanctuary, Melissa Maria Hurtado Alvarez

Graduate Theses, Dissertations, and Problem Reports

Effective management and monitoring of visitor recreational use is fundamental in marine protected areas. It is common to hear that tourism and outdoor recreation are often qualified as double-edged activities, making valuable socioeconomic contributions but also causing degradation of the environment. The convergence of social and natural resource research and practices can help managers to create better policies that will maximize human benefits from, and minimize human pressures on, ocean and coastal environments. For this study online surveys were sent via Qualtrics to email addresses obtained from the state of Florida during the summer of 2020. The first paper assessed …

On The Lagrangian Description And Uniqueness For The One-Dimensional Pressureless Euler System, Mark David Suder

Graduate Theses, Dissertations, and Problem Reports

In this work we show that the one-dimensional pressureless Euler system admits a Lagragian characterization under fairly general initial conditions, extending recent results by Hynd [7]. Moreover, we show that if the initial velocity is right-continuous and bounded, then we have uniqueness of this Lagrangian solution (called Sticky Particles Flow, or SPF solution), which coincides with the Scalar Conservation Laws (or SCL) solution. An important tool we employed in order to prove existence is a result by Gangbo et al. [5], which establishes a canonical (i.e. the flow is given by the optimal maps pushing the Lebesgue measure restricted to …

Enhancing Negative-Ion Native Mass Spectrometry With Field-Assisted Capillary Vibrating Sharp-Edge Spray Ionization (Cvssi), Kushani Udeshika Attanayake

Graduate Theses, Dissertations, and Problem Reports

Although the birth of native mass spectrometry (native MS) occurred only several years after the development of electrospray ionization (ESI), it is yet considered an emerging technique for MS-based studies. This stems in part from challenges associated with efficient ionization of biopolymers. Although steady gains in ion production for native structure characterization have been secured primarily with the use of nanoelectrospray ionization (nESI), under negative polarity, the ionization efficiency can be extensively reduced due to an effect called “corona discharge”. The corona discharge occurs at the tip of ESI emitters because of free electron acceleration in the high-field region produced …

A Snapshot Of Ancient Microbial Life: Microorganisms And Organic Compounds In Primary Fluid Inclusions In Bedded Halite, Neoproterozoic Browne Formation Of Central Australia, Sara I. Schreder-Gomes

Graduate Theses, Dissertations, and Problem Reports

Modern shallow brine environments contain an abundance of microorganisms. Microorganisms, mineral crystals, and air bubbles can be trapped with those brines in primary fluid inclusions in bedded halite as it grows in shallow saline surface waters. Primary fluid inclusions and their contents can be preserved, unaltered, for millions of years.

The ~830 million-year-old Browne Formation of central Australia contains intervals of bedded halite with unaltered primary fluid inclusions. Intervals of bedded halite were sampled in the Empress 1A core from ~1480 m – 1520 m depths. Here, I used petrography to describe suspect microorganisms and organic compounds that were trapped …

Plant Species Identification In The Wild Based On Images Of Organs, Meghana Kovur

Graduate Theses, Dissertations, and Problem Reports

Image-based plant species identification in the wild is a difficult problem for several reasons. First, the input data is subject to a very high degree of variability because it is captured under fully unconstrained conditions. The same plant species may look very different in different images, while different species can often appear very similar, challenging even the recognition skills of human experts in the field. The large intra-class and small inter-class image variability makes this a fine-grained visual classification problem. One way to cope with this variability and to reduce image background noise is to predict species based on the …