Digital Commons Network^™

Modeling, Fabrication, And Characterization Of Rf-Based Passive Wireless Sensors Composed Of Refractory Semiconducting Ceramics For High Temperature Applications, Kavin Sivaneri Varadharajan Idhaiam

Graduate Theses, Dissertations, and Problem Reports (ETD)

Real-time health monitoring of high temperature systems (>500^oC) in harsh environments is necessary to prevent catastrophic events caused by structural failures, varying pressure, and chemical reactions. Conventional solid-state temperature sensors such as resistance temperature detectors (RTDs) and thermocouples are restricted by their operating environments, sensor dimensions and often require external power sources for their operation. The current work presents the research and development of RF-based passive wireless sensing technology targeting high temperatures and harsh environmental conditions. Passive wireless devices are generally classified as near-field and far-field devices based on the interrogation distance. Near-field sensors are placed at …

Air-Assisted Communications Using Line-Of-Sight Links, Shaikha A. Alkandari

Graduate Theses, Dissertations, and Problem Reports (ETD)

Recently, there has been a rapid increase in the use of air-assisted communications involv-
ing the use of airborne platforms such as unmanned aerial vehicles (UAVs). In air-assisted
networks, the UAVs can act like base stations in a traditional cellular network as long as an
appropriate backhaul is available. Alternatively, the UAVs could serve as relays, for instance,
connecting two ground-based users who are within range of the UAV. UAVs have the benefit
of being deployed and reconfigured rapidly and on demand.
Meanwhile, there has been a trend towards the use of higher and higher frequencies,
including those in millimeter-wave …

Network Slicing In 5g: Admission, Scheduling, And Security, Raneem Jassim Alghawi

Graduate Theses, Dissertations, and Problem Reports (ETD)

In the past few decades, there was an increase in the number of devices that have wireless capabilities such as phones, televisions, and home appliances. With the high demand for wireless networking, the fifth generation (5G) of mobile networks was designed to support the different services of new applications. In addition, one of the technical issues that 5G would evolve is the increase in traffic and the need to satisfy the user’s experience. With the evolution of wireless networking and 5G, Network Slicing has been introduced to accommodate the diverse requirements of the applications. Thus, network slicing is the concept …

Development Of Oxide Dispersion Strengthening (Ods) Alloys Powder For Additive Manufacturing, Changyu Ma

Graduate Theses, Dissertations, and Problem Reports (ETD)

Additive manufacturing (AM) fabricated oxide dispersion strengthened (ODS) alloys are given high expectations for critical structural components such as the first stage turbine blade for their excellent creep strength and oxidation resistance compared to superalloys. However, the powder feedstock processing is still an open question since current state-of-the-art processes are not capable of achieving ultrafine strengthening elements such as Y₂O₃ in powder which leads to agglomeration issues in as-consolidated alloys. In this research, the oxidation behavior and stability of ultrafine oxide in AM-printed alloys using mechanically alloyed powders were evaluated at 1100 ^oC. In addition, a …

Analysis Of Emissions Profiles Of Hydraulic Fracturing Engine Technologies, Nicholas Joseph Wells

Graduate Theses, Dissertations, and Problem Reports (ETD)

In the past twenty years natural gas production in the United States has significantly increased. This is largely due to technological advancements in unconventional methods of horizontal drilling and hydraulic fracturing. With these new and improved technologies, the United States has been able to increase its natural gas dry production per year by 14.5 trillion cubic feet per year from 2001-2021, a 74.1% increase. Horizontal drilling allows the wellbore to have more contact with the source rock, thus allowing more hydrocarbons to be extracted. Hydraulic fracturing allows oil and gas companies to have access to low permeable source rock, previously …

Investigating The Marketing Language Among Online Retailers Of Violin Strings To Determine The Implied Aesthetic, Kira Kay Browning

Graduate Theses, Dissertations, and Problem Reports (ETD)

The aim of this research is to determine if language in the advertising of violin strings is acting as an exclusionary tool in favor of a Western art music “sound” produced by “classical” violinists. It posits that the marketing of strings to violinists is a topic laden with unacknowledged biases and values of musicians within Western art music. The aesthetic values attached to playing Western art music for the violin in the United States are passed on through pedagogic practice and acculturation of language. Product descriptions for strings in the United States employ language which adheres to these cultural values …

Development And Testing Of A Biochar Combustor For A Stirling Engine, Kyle Bryant Vickery

Graduate Theses, Dissertations, and Problem Reports (ETD)

Nonrenewable resources persist as a necessity for perpetuating the current technology and standards of living maintained throughout the world. Biochar is an alternative and renewable fuel source that constitutes the potential to provide energy comparable to coal. Designing and fabricating components that can efficiently harness biochar’s energy to power machinery would demonstrate a successful renewable energy source. The scope of this research is to explain the feasible design, fabrication, and results of technology involving the burning of biochar and transference of hot combustion products for the purpose of powering a Stirling Engine. This design consists of a solid fuel burner, …

Pathfinding Fast Radio Bursts Localizations Using Very Long Baseline Interferometry, Pranav Rohit Sanghavi

Graduate Theses, Dissertations, and Problem Reports (ETD)

Fast radio bursts (FRBs) are millisecond-duration, bright radio transients of extragalactic origin. The Canadian Hydrogen Intensity Mapping Experiment (CHIME) telescope’s CHIME/FRB instrument and other radio telescopes across the globe have detected hundreds of FRBs. Their origins are a mystery. Precise localization within the host is critical to distinguish between progenitor models. This can be achieved through Very Long Baseline Interferometry (VLBI). Until now, VLBI localizations have only been carried out in targeted follow-up observations of some repeating sources which comprise a small fraction of the FRBs.

For this work, an interferometric array of 6m dishes was constructed at the Green …

Post-Processing Precise Point Positioning Solutions With Parameter Optimization, Maria A. Gonzalez Castaneda

Graduate Theses, Dissertations, and Problem Reports (ETD)

Precise Point Positioning (PPP) technique can offer position solutions with centimeter-level accuracy by fusing precise satellite orbits and clocks with un-differenced, dual-frequency, pseudo-range, and carrier-phase observables. PPP presents a compelling alternative to Differential Global Positioning Systems, with the benefit that it only requires a single receiver and does not require simultaneous observations from many stations, making it appealing for ongoing research on hydro-graphic survey applications. The National Oceanic and Atmospheric Administration has been working on a buoy system tracked with a Global Positioning Systems receiver and Inertial Measurement Unit sensor using the PPP technique. In the interest of obtaining accurate …

Development Of Methane Emissions Model To Assess Fuel Recovery Potential At Gas Well Sites Using On Site Compression, Nicholas G. Lindenfeldar

Graduate Theses, Dissertations, and Problem Reports (ETD)

The US natural gas production and consumption has increased 85.5% since 2005 primarily due to the unconventional production methods of horizontal drilling and hydraulic fracturing. Natural gas used as a fuel has a lower greenhouse gas (GHG) footprint than coal and petroleum due to lower Carbon Dioxide (CO₂) emissions when combusted. However, the “greener” benefit to natural gas may be consumed by leaks in production and transmission systems. Methane (CH₄), the primary hydrocarbon in natural gas, has an estimated Global Warming Potential (GWP) of 28-36 over 100 years, meaning it can absorb 28-36 more energy than …

Uav Path Planning And Multi-Modal Localization For Mapping In A Subterranean Environment, Kieren Yoshiki Samarakoon

Graduate Theses, Dissertations, and Problem Reports (ETD)

The use of Unmanned Aerial Vehicles (UAVs), especially quadcopters, have become popular in academia and industry due to their small size and maneuverability. These UAVs can be programmed to autonomously execute missions that are usually difficult and risky for humans, such as subterranean exploration, infrastructure surveying, and even disaster response. However, inaccessible and remote environments pose a challenge in terms of navigation as they often lack access to Global Navigation Satellite System (GNSS) connections and lack features. To address these challenges, UAVs are equipped with multiple sensors to acquire different types of data. These include range, acceleration, and even images, …

Advanced Process Modeling And Optimization Of Amine-Based Carbon Capture Process, Paul Jide Terhemba Akula

Graduate Theses, Dissertations, and Problem Reports (ETD)

With the rise of carbondioxide (CO2) concentration in the atmosphere to more than 400 parts per million (ppm), research efforts have been focused on achieving net-zero carbon emission technologies. Post-combustion CO2 capture (PCC) is a key strategy in reducing CO2 emissions. Amine-based CO2 capture is the baseline technology for retrofitting existing power stations. However, the integration of amine-based PCC technology with power plants to reduce greenhouse gas emissions incurs a high energy penalty, decreasing a powerplant’s efficiency by about 23 percentage points. Understanding the capture plant dynamics plays an important role in its technical and economic performance. Rigorous models are …

Study Of Resonantly Stabilized Radicals In Combustion Environments, James H. Lee

Graduate Theses, Dissertations, and Problem Reports (ETD)

Resonantly stabilized radicals (RSRs) play an important role in combustion environments due to their high stability resulting from resonance. Many RSRs such as the propargyl, allyl, or benzyl radicals are precursors to the formation of polycyclic aromatic hydrocarbons (PAHs), which can aggregate to form soot. Due to their stability, these RSRs can accumulate in combustion environments in significant quantities. The primary way these radical species are consumed in flames or by reactions with other abundant radicals, by self-recombination of propargyl to form benzene, or in the form of other abundant radicals such as the hydroxyl radical. Experimentally determining the pathways …

A Workflow For Unconventional Reservoirs Optimization Using Supervised Machine Learning In Conjunction With Orthorhombic Elasticity Modeling, Aymen Ab Ali Alhemdi

Graduate Theses, Dissertations, and Problem Reports (ETD)

Due to the anisotropy and heterogeneous nature of unconventional reservoirs like shale, a comprehensive parametric study to optimize hydraulic fracture treatment for such reservoirs is a tough challenge, especially when natural fractures are present. Most of the current frac simulators do not consider the anisotropy of rock elasticity in the shales. Besides, using the fracture simulation linked with reservoir simulation for the parametric study to understand the impact of multiple different design parameters on fracture propagation and production is time expensive and low efficient. The study proposes a workflow including a new orthorhombic (OB) rock algorithm to interpret geomechanical properties …

Development Of An Entry-Scale Modeling Methodology To Provide Ground Reaction Curves For Longwall Gateroad Support Evaluation, Haochen Zhao

Graduate Theses, Dissertations, and Problem Reports (ETD)

Longwall gateroad entries are generally subjected to severe mining-induced stress changes and deformations; they are prone to large roof falls, floor heaves, and rib sloughing. The standing support system in underground mines needs to be carefully designed to compensate for the mining-induced deformation of the surrounding rock mass and consecutively protect the integrity of gateroad entries. Local geology, together with mining-induced stress redistribution, influences the ground response and plays a major role in the performance of a standing support design. In the US, Support Technology Optimization Program (STOP) and its Ground Reaction Curve (GRC) design criteria have been applied to …

Development And Verification Of Flight Data Informed Performance Estimation And Prediction Simulation Tool For Small Electrical Multi-Rotor Uav, Nicholas Scott Borelle

Graduate Theses, Dissertations, and Problem Reports (ETD)

While small scale multi-rotor aircraft are becoming an increasingly large market with applications emerging every day, their ability to have both a high endurance/long range and a high speed/performance flight is severely limited. This leads to uncertainty in mission planning and aircraft design, specifically when deciding mission length and available on-board energy. Uncertainty like this leads to an increased chance of failure to complete the mission, and a failure to recover the aircraft. Considering that these aircraft are used by everyone from hobbyists to commercial companies to military personnel, the applications and missions being flown carry importance and a serious …

Microwave-Assisted Carbon Nanotube Growth From Methane On Surface Catalyst Exsolving Perovskite Oxide, Angela M. Deibel

Graduate Theses, Dissertations, and Problem Reports (ETD)

The novel method of using a perovskite exsolution catalyst, strontium titanium nickel oxide (STNO), proved capable of simultaneously producing carbon nanotubes (CNTs) and CO_x-free hydrogen during methane decomposition under microwave irradiation. An optimization of common perovskite materials was conducted for microwave-responsiveness with the results reported in this study. Out of the materials screened, strontium titanium nickel oxide (STNO) was the best candidate to achieve an acceptable methane conversion rate as well as a decent responsiveness to microwave. STNO was further optimized through Ni content, reduction dwell time, and reduction temperature to produce the best methane conversion and CNT …

Face Recognition With Attention Mechanisms, Qiangchang Wang

Graduate Theses, Dissertations, and Problem Reports (ETD)

Face recognition has been widely used in people’s daily lives due to its contactless process and high accuracy. Existing works can be divided into two categories: global and local approaches. The mainstream global approaches usually extract features on whole faces. However, global faces tend to suffer from dramatic appearance changes under the scenarios of large pose variations, heavy occlusions, and so on. On the other hand, since some local patches may remain similar, they can play an important role in such scenarios. Existing local approaches mainly rely on cropping local patches around facial landmarks and then extracting corresponding local representations. …

Finite Element Method Calculation Of A Prestressed Self Consolidating Concrete Beam, Vladyslav Machulsky

Graduate Theses, Dissertations, and Problem Reports (ETD)

In this study, a prestressed concrete box beam produced for the Stalnaker Run Bridge (SRB) replacement project using self-consolidating concrete (SCC) was simulated using finite element method (FEM) numerical technique. ANSYS, a commercial FEM software, was used to build the prestressed SCC box beam model. The FEM model was developed to understand the behavior of concrete and steel under prestressing loads, long-term effects, and superimposed loads. The SOLID65 and REINF264 element types were chosen to simulate the behavior of concrete and steel materials. Experimentally measured mechanical properties of concrete from the SRB project were used in the analysis allowing for …

Gan-Based Super-Resolution And Segmentation Of Retinal Layers In Optical Coherence Tomography Scans, Paria Jeihouni

Graduate Theses, Dissertations, and Problem Reports (ETD)

Optical Coherence Tomography (OCT) has been identified as a noninvasive and cost-effective imaging modality for identifying potential biomarkers for Alzheimer's diagnosis and progress detection. Current hypotheses indicate that retinal layer thickness, which can be assessed via OCT scans, is an efficient biomarker for identifying Alzheimer's disease. Due to factors such as speckle noise, a small target region, and unfavorable imaging conditions manual segmentation of retina layers is a challenging task. Therefore, as a reasonable first step, this study focuses on automatically segmenting retinal layers to separate them for subsequent investigations. Another important challenge commonly faced is the lack of clarity …

Charge Dynamics Of Inas Quantum Dots Under Resonant And Above-Band Excitation, Gary R. Lander Jr

Graduate Theses, Dissertations, and Problem Reports (ETD)

Research involving light-matter interactions in semiconductor nanostructures has been an interesting topic of investigation for decades. Many systems have been studied for not only probing fundamental physics of the solid state, but also for direct development of technological advancements. Research regarding self-assembled, epitaxially grown quantum dots (QDs) has proven to be prominent in both regards. The development of a reliable, robust source for the production of quantum bits to be utilized in quantum information protocols is a leading venture in the world of condensed matter and solid-state physics. Fluorescence from resonantly driven QDs is a promising candidate for the production …

Integrated Large Discontinuity Factor, Lamodel And Stability Mapping Approach For Stone Mine Pillar Stability, Mustafa Baris Ates

Graduate Theses, Dissertations, and Problem Reports (ETD)

The objective of this research is to develop a software tool that integrates the large discontinuity factor (LDF) and the Boundary Element Method software (BEM), LaModel, to allow stone mine operators to assess the impact of the large discontinuities on local pillar stability. National Institute for Occupational Safety and Health (NIOSH) published design guidelines for underground stone mines to guide the industry in designing pillar and roof support. These guidelines emphasize the impact of large, angular discontinuities on pillar strength. Esterhuizen et al. (2011) derived the large discontinuity factor (LDF) to account for the impact of discontinuities on pillar stability …

Elucidating Biogeochemical Reactions Of Iron For Ammonium Removal And Nutrient Recovery From Wastewaters: Moving Toward Sustainable Wastewater Management, Rifat Anwar

Graduate Theses, Dissertations, and Problem Reports (ETD)

Development and applications of anaerobic treatment technologies has been discussed as an effective alternative to conventional aerobic processes for removal of nitrogen from wastewaters. With abundance of iron and its high reduction potential, employing ferric reduction-based reaction pathways in engineering processes could be an effective strategy to promote energy efficiency of wastewater treatment. In particular, ferric reduction coupled to ammonium oxidation (Feammox), a novel microbial metabolic function recently found to occur under anaerobic/anoxic condition through iron dosing, can be used for nitrogen pollutant removal. Iron dosing for wastewater treatment could also promote other microbial and chemical reactions that facilitate nutrient …

Nano-, Encapsulated Manganese Oxide (Nemo) Particles For Mri Enhancement In Microfluidic Tumor Models, Kasey Alexis Freshwater

Graduate Theses, Dissertations, and Problem Reports (ETD)

Breast cancer is among the deadliest cancers in women, with approximately 2.3 million new cases and 685,000 deaths reported globally in 2020 alone. Magnetic Resonance Imaging (MRI) is commonly used to diagnose, stage, and develop treatment plans for patients predisposed to breast cancer. However, current MRI-based screening of breast cancer has high false-positive rates up to 25%, leading to unnecessary invasive follow-up screening and testing. The gold-standard intravenous gadolinium (Gd)-based contrast agents (GBCAs) account for false-positive rates because they are always “ON”, providing a constant MRI signal that highlights both benign and malignant tumors. The work detailed in this thesis …

Expanding The Applicability Of Press-Brake-Formed Tub Girders Through The Extension Of The Maximum Span Length And The Evaluation Of Pier Continuity, Robert M. Tennant

Graduate Theses, Dissertations, and Problem Reports (ETD)

The Short Span Steel Bridge Alliance (SSSBA) is a group of bridge and buried soil steel structure industry leaders who provide educational information on the design and construction of short-span steel bridges in installations up to 140 feet in length. Within the SSSBA technical working group, a modular, shallow press-brake-formed tub girder (PBFTG) was developed to address the demand in the short-span steel bridge market for rapid infrastructure replacement solutions. PBFTGs consist of modular, shallow, trapezoidal boxes fabricated from cold-bent structural steel plate. A concrete deck, or other deck option, may be placed on the girder, and the modular unit …

Top-Down & Bottom-Up Approaches To Robot Design, Dylan Michael Covell

Graduate Theses, Dissertations, and Problem Reports (ETD)

This thesis presents a study of different engineering design methodologies and demonstrates their effectiveness and limitations in actual robot designs. Some of these methods were blended together with focus on providing an easily interpreted project design flow while implementing more bottom-up, or feedback, elements into the design methodology. Typically design methods are learned through experience, and design taught in academia aims to shape and formalize previous experience. Usually, inexperienced engineers are taught approaches resembling the Verein Deutscher Ingenieure (VDI) 2221 process. This method presented by the Association of German Engineers in 2006 is regarded as the general system design process. …

Multisided Quality Inspection In Smart Manufacturing Systems, Milica Babic

Graduate Theses, Dissertations, and Problem Reports (ETD)

As technology advances so does its adoption in industry and our everyday lives. We use technology to better our daily tasks whether at home or in the workplace. In the workplace there are many benefits of implementing new technologies to improve processes and products while at the same time being cautious about associated costs. Costs associated with incorporating new digital technologies include but are not limited to hardware and software, system integration, testing, and employee training. Now that we have entered the era of the Fourth Industrial Revolution, there are many opportunities for improvements in manufacturing that involve Smart Digital …

The Effect Of A Standardized Handoff Tool On Communication, Interunit Transitions, And Wait Time: A Quality Improvement Project, Silvia N. Myndresku

Graduate Theses, Dissertations, and Problem Reports (ETD)

This project sought not only to improve the communication and interunit transitions of care between emergency department providers (EDPs) and inpatient providers (IPs) using a standardized handoff tool, but also to reduce the Emergency Room (ED) wait time for patients admitted to the community hospital. The project employed a quantitative quasi-experimental pre-test/post-test design to explore provider satisfaction with an evidence-based standardized handoff tools and wait time. Forty-eight providers completed the survey before the I-PASS implementation, and 43 providers completed the survey post I-PASS implementation. Though not statistically significant, data indicates that wait time increased for the post-implementation months of December, …

Discussing Changes In Historical Human–Environmental Dynamics Through Ecosystem Services Interactions And Future Scenarios In A Rural-Mining Region Of Central Appalachians, Vincenzo Cribari

Graduate Theses, Dissertations, and Problem Reports (ETD)

The aim of this dissertation was to investigate how recent processes of land-change induced by humans contributed to the shaping and alteration of the current landscape in a headwater system of Central Appalachians in West Virginia (US), to understand the interactions and tradeoffs among ecosystems services and address potential solutions for targeting more sustainable human-environment interactions in a region that is deeply grounded on extractive economies. The multitiered objective was addressed through different research phases in order to unfold and disentangle a series of complex problems that the study area presents. Three main phases were used; they corresponded to distinct …

Small And Micro Business Resources In The Post-Pandemic Period: A Perspective From Local Bridal Boutique Businesses In West Virginia, Ishtehar Sharif Swazan

Graduate Theses, Dissertations, and Problem Reports (ETD)

In widely dispersed small communities, local and regional businesses dominate West Virginia, an eastern state of the United States in the Appalachian Mountains where small and micro businesses constitute 98.9% of all businesses and contributes 49.1% of the state’s total employment. These businesses create jobs, help build a strong financial position for the state, and promote community-building and social activities. These businesses are unique as they sustain themselves while competing with national and regional retail chains and carving out a customer for themselves. However, the damage caused by the spread of Covid-19 is having a devastating effect on the small …