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West Virginia University

2021

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Articles 1 - 30 of 83

Full-Text Articles in Physical Sciences and Mathematics

Exploring Dft+U Parameter Space With A Bayesian Calibration Assisted By Markov Chain Monte Carlo Sampling, Pedram Tavadze, Reese Boucher, Guillermo Avendaño-Franco, Keenan X. Kocan, Sobhit Singh, Viviana Dovale-Farelo, Wilfredo Ibarra-Hernández, Matthew B. Johnson, David S. Mebane, Aldo H. Romero Nov 2021

Exploring Dft+U Parameter Space With A Bayesian Calibration Assisted By Markov Chain Monte Carlo Sampling, Pedram Tavadze, Reese Boucher, Guillermo Avendaño-Franco, Keenan X. Kocan, Sobhit Singh, Viviana Dovale-Farelo, Wilfredo Ibarra-Hernández, Matthew B. Johnson, David S. Mebane, Aldo H. Romero

Faculty & Staff Scholarship

The density-functional theory is widely used to predict the physical properties of materials. However, it usually fails for strongly correlated materials. A popular solution is to use the Hubbard correction to treat strongly correlated electronic states. Unfortunately, the values of the Hubbard U and J parameters are initially unknown, and they can vary from one material to another. In this semi-empirical study, we explore the U and J parameter space of a group of iron-based compounds to simultaneously improve the prediction of physical properties (volume, magnetic moment, and bandgap). We used a Bayesian calibration assisted by Markov chain Monte Carlo …


On The Use Of Minimum Penalties In Statistical Learning, Ben Sherwood, Bradley S. Price Jul 2021

On The Use Of Minimum Penalties In Statistical Learning, Ben Sherwood, Bradley S. Price

Faculty & Staff Scholarship

Modern multivariate machine learning and statistical methodologies estimate parameters of interest while leveraging prior knowledge of the association between outcome variables. The methods that do allow for estimation of relationships do so typically through an error covariance matrix in multivariate regression which does not scale to other types of models. In this article we proposed the MinPEN framework to simultaneously estimate regression coefficients associated with the multivariate regression model and the relationships between outcome variables using mild assumptions. The MinPen framework utilizes a novel penalty based on the minimum function to exploit detected relationships between responses. An iterative algorithm that …


Do Mitigated Wetlands Support Similar Small Mammal Communities As Natural Wetlands?, Krista Noe, Mack Frantz, Christopher T. Rota, Jim Anderson May 2021

Do Mitigated Wetlands Support Similar Small Mammal Communities As Natural Wetlands?, Krista Noe, Mack Frantz, Christopher T. Rota, Jim Anderson

Presentations

Wetlands provide many ecosystem services and play an important ecological role in wildlife communities. Although wetland mitigation is a standard tool to combat losses to natural wetlands, it is essential to understand if mitigated wetlands are truly replacing natural wetlands in their full capacity. Because one important role of wetlands is to provide habitat for wildlife communities, it is important to determine if these created or restored wetlands can foster a wildlife community that is similar to natural wetlands. One understudied taxa in the realm of wetland mitigation research is small mammals. Our objectives are to examine community composition, occupancy, …


Relating Recharge Mechanisms To Dissolved Inorganic Carbon Dynamics In An Updip Appalachian Coal Mine Discharge, Matthew L. Bell May 2021

Relating Recharge Mechanisms To Dissolved Inorganic Carbon Dynamics In An Updip Appalachian Coal Mine Discharge, Matthew L. Bell

Presentations

Impaired drainage from active and abandoned mines degrades the water quality of receiving streams and aquifers. Coal mine drainage (CMD) has been studied for decades in Appalachia, but unknowns and uncertainties are still present, including the influence of mine hydrogeology on the outflow chemistry of above-drainage mines. To evaluate the influence of recharge type on above-drainage mine dissolved inorganic carbon chemistry, samples were collected every two weeks at a CMD outflow treatment system in Harrison County, West Virginia. Samples were collected to measure geochemical changes taking place in the mine workings and along the flowpath of the passive treatment system. …


Comparison Of Methods For Estimating Carbon Evasion And Export Associated With A Coal Mine Discharge, Kyle Lee, Dorothy J. Vesper May 2021

Comparison Of Methods For Estimating Carbon Evasion And Export Associated With A Coal Mine Discharge, Kyle Lee, Dorothy J. Vesper

Presentations

The evasion of CO2 from terrestrial waters plays a role in the global cycling of carbon but there are few datasets that have an accurate accounting of the flux. It has been shown that discharges from coal mines can have elevated concentrations of CO2 due to sulfuric acid-driven dissolution of carbonate rock. In this study, we compared three methods for calculating the export dissolved inorganic carbon (DIC) and the evaluation of CO2 from an abandoned-mine discharge in West Virginia. In Method #1, the source flux is calculated from the discharge and the concentrations at the portal. In Method #2, the …


Quantifying The Contribution Of Solid Precipitates To The Total Alkalinity In A Coal-Mine Discharge, Lili Lei, Dorothy Vesper May 2021

Quantifying The Contribution Of Solid Precipitates To The Total Alkalinity In A Coal-Mine Discharge, Lili Lei, Dorothy Vesper

Presentations

Flocculates and precipitates from coal mine drainage (CMD) are an integral part of the geochemical setting in mining-impacted streams. The precipitates may be very small, amorphous, and, depending on their chemistry, play a role in the storage and release of alkalinity. To evaluate the potential impact of CMD-solids on alkalinity, we conducted various tests using model and natural solids. Laboratory measurements of alkalinity are operationally defined by a titration to a fixed pH. When the solid-solution mixtures were tested using the standard alkalinity measurement method, no alkalinity could be detected; however, a possible reason for that was that the standard …


Development Of A Python Library To Facilitate Wqx Dataset Exchanges, Jonathan Musselwhite, Fernando Rojano May 2021

Development Of A Python Library To Facilitate Wqx Dataset Exchanges, Jonathan Musselwhite, Fernando Rojano

Presentations

The assistance of programming tools to speed up the exchange of water quality datasets are necessary. These tools reduce and simplify the steps currently needed to transfer datasets from water quality monitoring stations to public databases. Here it is presented a library developed in Python that programmatically covers the steps related to the upload of datasets following the framework of the Water Quality Exchange (WQX) of the US EPA. This library is mainly characterized by its ability to efficiently connect and transfer data formatted as CSV or XLSX files via the WQX to the National STORET Data Warehouse by mostly …


Functionalized Polycarbonate Commercial Filters For Water Purification, Jeremy Mccloud, Ashton Caruthers, Kennedy Shoults, Rick Sharpe, Sean P. Mcbride May 2021

Functionalized Polycarbonate Commercial Filters For Water Purification, Jeremy Mccloud, Ashton Caruthers, Kennedy Shoults, Rick Sharpe, Sean P. Mcbride

Presentations

Can commerercially available filtration membranes be easily functionalized in such a way to enhence the removal the charged contaminants in the water treatment process? The literature demonstrates there have been two pioneering works that demonstrated that Ultrathin Self-Assembled Nanoparticle (USANP) membranes (composed of ~5 nm diameter metallic gold nanoparticles surrounded by organic ligands) when applied to commercial membranes displayed charge sensitive rejection to molecular dyes and also have the ability to charge modify the openings in commercial filters. The rejection mechanisms in these works are proposed to be either size dependent or charged based. Recent experimental results have demonstrated that …


Evaluating Impacts Of Anthropogenic Disturbance To Wetland Water Quality Functions, Sindupa De Silva, Jim Anderson, Jason A. Hubbart, Michael P. Strager, Elliott Kellner, Christopher T. Rota, Elizabeth A. Byers May 2021

Evaluating Impacts Of Anthropogenic Disturbance To Wetland Water Quality Functions, Sindupa De Silva, Jim Anderson, Jason A. Hubbart, Michael P. Strager, Elliott Kellner, Christopher T. Rota, Elizabeth A. Byers

Presentations

Wetland ecosystems play fundamental roles in regulating our freshwater resources, yet they are not comprehensively protected from degradation and loss. West Virginia, USA has wetlands across diverse landscapes and geography that feed into both the Chesapeake Bay and Gulf of Mexico. The state is also comprised of diverse anthropogenic land-use practices. We are assessing 200 wetlands over 2 years to evaluate how anthropogenic disturbance impact wetland water quality functions. Select water quality parameters (20), and relative diversity and abundance of vegetation and macroinvertebrates will be used as bioindicators. They will be compared with GIS assessments of watershed land cover/ land-use …


Boulders As A Lithologic Control On River And Landscape Response To Tectonic Forcing At The Mendocino Triple Junction, Charles Shobe, Georgina Bennett, Gregory Tucker, Kevin Roback, Scott Miller, Joshua Roering Mar 2021

Boulders As A Lithologic Control On River And Landscape Response To Tectonic Forcing At The Mendocino Triple Junction, Charles Shobe, Georgina Bennett, Gregory Tucker, Kevin Roback, Scott Miller, Joshua Roering

Faculty & Staff Scholarship

Constraining Earth’s sediment mass balance over geologic time requires a quantitative understanding of how landscapes respond to transient tectonic perturbations. However, the mechanisms by which bedrock lithology governs landscape response remain poorly understood. Rock type influences the size of sediment delivered to river channels, which controls how efficiently rivers respond to tectonic forcing. The Mendocino triple junction region of northern California, USA, is one landscape in which large boulders, delivered by hillslope failures to channels, may alter the pace of landscape response to a pulse of rock uplift. Boulders frequently delivered by earthflows in one lithology, the Franciscan mélange, have …


Development Of Multi-Catchment Rating Curves For Streams Of Appalachian Mixed-Land-Use Watersheds: Preliminary Results, Zachary A. Heck Jan 2021

Development Of Multi-Catchment Rating Curves For Streams Of Appalachian Mixed-Land-Use Watersheds: Preliminary Results, Zachary A. Heck

Graduate Theses, Dissertations, and Problem Reports

Anthropogenic activities can alter the quantity and quality of water. Traditional monitoring of streamflow involves measurements of stage (mm), or water height, and discharge (i.e., streamflow) (m3 s -1 ) above a local datum. However, while stage is relatively easily monitored, continuous streamflow measurement is often impractical and prohibitively expensive. To address this challenge, rating curve equations can be developed to convert stage to flow. To establish a series of rating curves for flow estimations in Appalachia, an investigation was conducted in a representative urbanizing, mixed-land-use watershed in north-central West Virginia consisting of 21 nested stream gauge sites. At each …


The Role Of Infrequently Mobile Boulders In Modulating Landscape Evolution And Geomorphic Hazards, Charles M. Shobe, Jens M. Turowski, Ron Nativ, Rachel C. Glade, Georgina L. Bennett, Benedetta Dini Jan 2021

The Role Of Infrequently Mobile Boulders In Modulating Landscape Evolution And Geomorphic Hazards, Charles M. Shobe, Jens M. Turowski, Ron Nativ, Rachel C. Glade, Georgina L. Bennett, Benedetta Dini

Faculty & Staff Scholarship

A landscape’s sediment grain size distribution is the product of, and an important influence on, earth surface processes and landscape evolution. Grains can be large enough that the motion of a single grain, infrequently mobile in size-selective transport systems, constitutes or triggers significant geomorphic change. We define these grains as boulders. Boulders affect landscape evolution; their dynamics and effects on landscape form have been the focus of substantial recent community effort. We review progress on five key questions related to how boulders influence the evolution of unglaciated, eroding landscapes: 1) What factors control boulder production on eroding hillslopes and the …


Valorization Of Xylan In Agroforestry Waste Streams, Harrison Appiah Jan 2021

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 Jan 2021

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 …


Arrow Spaces: A Unified Algebraic Approach To Euclidean Geometry And Inner Product Spaces, Hussin M. Albahboh Jan 2021

Arrow Spaces: A Unified Algebraic Approach To Euclidean Geometry And Inner Product Spaces, Hussin M. Albahboh

Graduate Theses, Dissertations, and Problem Reports

Given a postulated set of points, an algebraic system of axioms is proposed for an ``arrow space". An arrow is defined to be an ordered set of two points (T,H), named respectively Tail and Head. The set of arrows is an arrow space. The arrow space is axiomatically endowed with an arrow space ``pre-inner product" which is analogous to the inner product of an inner product vector space over R. Using this arrow space pre-inner product, various properties of the arrow space are derived and contrasted with the properties of a vector space over R. The axioms …


Heterogeneous Generalizations Of Vertex Coloring, Lucian Ciletti Mazza Jan 2021

Heterogeneous Generalizations Of Vertex Coloring, Lucian Ciletti Mazza

Graduate Theses, Dissertations, and Problem Reports

This dissertation proves a collection of results in some heterogeneous generalizations of vertex coloring, i.e. generalizations in which the relationship between the colors of two adjacent vertices may differ throughout the graph. For the most part, the results are from group coloring, group list coloring, and DP coloring. The main results are as follows: a group list coloring analogue of Brooks' Theorem for multigraphs, a result linking group structure (rather than only group size) with group coloring, some results involving coloring edge-disjoint unions, and an examination of the relationship between the group and DP coloring numbers of a multigraph and …


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 Jan 2021

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 …


Can Stable Isotopes From Tree Rings Improve Our Understanding Of Past Variability In The Southern Annular Mode?, Zachary Grzywacz Jan 2021

Can Stable Isotopes From Tree Rings Improve Our Understanding Of Past Variability In The Southern Annular Mode?, Zachary Grzywacz

Graduate Theses, Dissertations, and Problem Reports

Few annually dated stable isotope records exist across Oceania. In mid- to high-latitude locations in South America, tree-ring stable isotopes provide information about past climate dynamics such as the Southern Annular Mode (SAM). The SAM drives latitudinal shifts in Southern Hemisphere westerly winds, influencing temperature and moisture delivery across the mid- to high-latitudes, including Tasmania. Combinations of paleoclimate proxies from across the Southern Ocean might provide insight into dynamic processes like the SAM that are difficult to measure with a single proxy. Measuring stable carbon and oxygen isotope ratios from tree rings in Tasmania could provide complementary data to contribute …


Supporting Student Success And Persistence In Stem With Active Learning Approaches In Emerging Scholars Classrooms, David Miller, Jessica Deshler, Tim Mceldowney, John Stewart, Edgar Fuller, Matt Pascal, Lynnette Michaluk Jan 2021

Supporting Student Success And Persistence In Stem With Active Learning Approaches In Emerging Scholars Classrooms, David Miller, Jessica Deshler, Tim Mceldowney, John Stewart, Edgar Fuller, Matt Pascal, Lynnette Michaluk

Faculty & Staff Scholarship

Over the last several decades, Emerging Scholars Programs (ESPs) have incorporated active learning strategies and challenging problems into collegiate mathematics, resulting in students, underrepresented minority (URM) students in particular, earning at least half of a letter grade higher than other students in Calculus. In 2009, West Virginia University (WVU) adapted ESP models for use in Calculus I in an effort to support the success and retention of URM STEM students by embedding group and inquiry-based learning into a designated section of Calculus I. Seats in the class were reserved for URM and first- generation students. We anticipated that supporting students …


The Impact Of Unsaturated Zone Thickness On The Severity Of Saltwater Intrusion In Coastal Aquifers From Overtopping, Dennis Jesse Carpinello Jan 2021

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 …


Topic Modeling And Cultural Nature Of Citations, Marie Coraline Dumaz Jan 2021

Topic Modeling And Cultural Nature Of Citations, Marie Coraline Dumaz

Graduate Theses, Dissertations, and Problem Reports

Ever since the beginning of research journals, the number of academic publications has been increasing steadily. Nowadays, especially, with the new importance of online open-access journals and databases, research papers are more easily available to read and share. It also becomes harder to keep up with novelties and grasp an idea of the general impact of a given researcher, institution, journal, or field. For this reason, different bibliometric indicators are now routinely used to classify and evaluate the impact or significance of individual researchers, conferences, journals, or entire scientific communities. In this thesis, we provide tools to study trends in …


Effects Of Multiple Stressors On Aquatic Macroinvertebrate Communities In A Mixed-Land-Use Watershed, Joellen Stivala Jan 2021

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.). …


Bypassing The Blood-Brain Barrier: A Physical And Pharmacological Approach For The Treatment Of Metastatic Brain Tumors, Samuel A. Sprowls Jan 2021

Bypassing The Blood-Brain Barrier: A Physical And Pharmacological Approach For The Treatment Of Metastatic Brain Tumors, Samuel A. Sprowls

Graduate Theses, Dissertations, and Problem Reports

This dissertation (a) provided an in depth literature review of methods to disrupt the BBB/BTB and improve therapeutic distribution to brain tumors, (b) evaluated the use of azacitidine as a single agent therapy for the treatment of brain metastasis of breast cancer and a potential molecular mechanism by which brain tropic cells are sensitized to hypomethylating agents, (c) determined the impact cannabidiol has on P-glycoprotein mediated efflux at the blood-brain barrier and its potential for use as a single agent treatment for metastatic brain tumors, (d) developed a preclinical radiation therapy protocol for use in small animals and in vitro …


Effects Of Different Liquid Smoke Treatments On Osmotic Dehydration Of Apple Cubes, Rohit Singh Jan 2021

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 …


Independent, Semi-Automated Classification Of Petrographic Features In Volcanic Rocks Using Fiji And Weka, Holly Danielle Pettus Jan 2021

Independent, Semi-Automated Classification Of Petrographic Features In Volcanic Rocks Using Fiji And Weka, Holly Danielle Pettus

Graduate Theses, Dissertations, and Problem Reports

Traditional methods of collecting quantitative petrographic data from thin sections (modal mineralogy, size distribution, shapes, etc.) are time- and labor-intensive, and rarely have sample sizes adequate to statistically describe complex rocks (i.e. volcanic rocks). Although manual counting and measurements are now routinely supplemented by digital image analysis, the majority of quantitative petrographic studies still go through a manual digitization stage where object classes are traced before further analyses. This is a major rate-limiting step that reproduces the same problems of small n-values resulting from significant effort. We have valuated the potential and limitations of using the Trainable Weka Segmentation (TWS) …


Examining West Virginia's Economic Development: Natural Resources, Development Agencies, And Labor Force Development, Gaillynn Marie Bowman Jan 2021

Examining West Virginia's Economic Development: Natural Resources, Development Agencies, And Labor Force Development, Gaillynn Marie Bowman

Graduate Theses, Dissertations, and Problem Reports

Examining West Virginia's Economic Development: Natural Resources, Development Agencies, and Labor Force Development Gaillynn Bowman Economic development is well-recognized as being fundamental to facilitating an overall improved quality of life for communities and their residents. Throughout West Virginia’s history, the state has experienced economic hardships caused by boom and bust cycles associated with resource extraction. This dissertation consists of three essays that explore the impacts of economic development activities, including conservation programs, economic development agency initiatives, and workforce development agencies. The first essay explores the relationship nonresident landowners have with the conservation programs within West Virginia, specifically the Natural Resources …


Algebraic, Analytic, And Combinatorial Properties Of Power Product Expansions In Two Independent Variables., Mohamed Ammar Elewoday Jan 2021

Algebraic, Analytic, And Combinatorial Properties Of Power Product Expansions In Two Independent Variables., Mohamed Ammar Elewoday

Graduate Theses, Dissertations, and Problem Reports

Let $F(x,y)=I+\hspace{-.3cm}\sum\limits_{\substack{p=1\\m+n=p}}^{\infty}\hspace{-.3cm}A_{m,n}x^my^n$ be a formal power series, where the coefficients $A_{m,n}$ are either all matrices or all scalars. We expand $F(x,y)$ into the formal products $\prod\limits_{\substack{p=1\\m+n=p}}^{\infty}\hspace{-.3cm}(I+G_{m,n}x^m y^n)$, $\prod\limits_{\substack{p=1\\m+n=p}}^{\infty}\hspace{-.3cm}(I-H_{m,n}x^m y^n)^{-1}$, namely the \textit{ power product expansion in two independent variables} and \textit{inverse power product expansion in two independent variables} respectively. By developing new machinery involving the majorizing infinite product, we provide estimates on the domain of absolute convergence of the infinite product via the Taylor series coefficients of $F(x,y)$. This machinery introduces a myriad of "mixed expansions", uncovers various algebraic connections between the $(A_{m,n})$ and the $(G_{m,n})$, and uncovers various algebraic …


Experimental Investigations Of Contact Friction And Transport Properties Of Monolayer And Bilayer Graphene, Prakash Gajurel Jan 2021

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 …


Refining The Sedimentology And Geochemistry Of The Mid-Permian Blaine Formation Of The Rebecca K. Bounds Core From Greeley County, Kansas, Brigitte Petras Jan 2021

Refining The Sedimentology And Geochemistry Of The Mid-Permian Blaine Formation Of The Rebecca K. Bounds Core From Greeley County, Kansas, Brigitte Petras

Graduate Theses, Dissertations, and Problem Reports

Red siliciclastics and evaporites of Permian Nippewalla Group in mid-continental US were deposited in western equatorial Pangea. Previous studies of these rocks record Permian air temperatures as high as 73 °C, saline lake waters with a pH as low as ~1, and sedimentology that shows arid conditions. This current study conducts detailed sedimentological observations and geochemical analyses of the Blaine Formation of the Nippewalla Group. The Rebecca K. Bounds core from west-central Kansas is used to interpret the depositional environments and diagenetic history of the Blaine Formation.

The lithologies of the Blaine Formation, listed in order of most to least …


Investigation Of Ions Accelerated Through Electrostatic Menisci In An Inductively Coupled Plasma, David D. Caron Jan 2021

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 …