Digital Commons Network^™

Life Cycle Impacts Of Hardwood Forest Resources For Sustainable Bioenergy And Bioproducts In The Eastern United States, Jinghan Zhao

Graduate Theses, Dissertations, and Problem Reports (ETD)

A life-cycle impact assessment of hardwood resources across the eastern United States was conducted based on the life-cycle inventory data for hardwood forest resource management and was integrated with the Forest Vegetation Simulator (FVS). This integration allowed for the analysis of forest carbon dynamics in the four subregions: northeast (NE), mid-Atlantic (MA), southeast (SE), and northcentral (NC). The system boundary was selected to be consistent with the A1 module (extraction and upstream production) required by an Environmental Product Declaration (EPD) for wood products. The results indicated that uneven-aged management (UA) yielded higher carbon stocks than even-aged management (EA) across all …

Studies In Nonlinear Chemical Dynamics Of Propagating Precipitation Waves, Md Boshir Ahmed

Graduate Theses, Dissertations, and Problem Reports (ETD)

This dissertation explores the intricate dynamics of pattern formation in nonlinear chemical systems, specifically focusing on the phenomena of propagating waves and Liesegang patterns in aluminum and zinc hydroxide systems. Through a combination of experimental setups and theoretical models, the study delves into the mechanisms driving these patterns, providing insights into their formation, evolution, and underlying principles.

The research begins with an introduction to nonlinear dynamics and pattern formation, emphasizing the significance of these concepts in understanding complex natural systems. It then moves into a detailed examination of Liesegang bands, discussing classical and reverse systems, and introducing the redissolution process …

The Impact Stress On The Fracture Conductivity And The Productivity Of The Marcellus Shale Horizontal Well, Simon Hanna Menhem

Graduate Theses, Dissertations, and Problem Reports (ETD)

The increase in effective stress during depletion adversely impacts the productivity of the multi-stage fractured Marcellus shale horizontal well. The geomechanical properties and proppant size influence the degree of shale compaction, the fracture conductivity, and the well productivity. This study seeks to assess the impact of net stress increase during depletion on the productivity of multi-stage fractured Marcellus shale horizontal wells. To investigate the impact of the net stress increase, a model for Bogges-5H well was developed based on the petrophysical and geomechanical properties of the shale obtained from the core plugs and well logs measurements from the pilot (Bogges …

Implementing Unmanned Aerial Vehicles To Collect Human Gait Data At Distance And Altitude For Identification And Re-Identification, Donn E. Bartram

Graduate Theses, Dissertations, and Problem Reports (ETD)

Gait patterns are a class of biometric information pertaining to the way a person moves and poses. Gait information is unique to each person and can be used to identify and reidentify people. Historically, this task has been achieved through the use of multiple ground-based imaging sensors. However, as Unmanned Aerial Vehicles (UAVs) advance, they present the opportunity to evolve the process of persons identification and re-identification. Collecting human gait data using UAVs at distances ranging from 20m to 500m and altitudes ranging from 0m to 120m is a challenging task. The current biometric data collection methods, primarily designed for …

Understanding Learners' Perception Of Virtual Reality-Assisted Learning In Engineering Education, Mohammad Samin Mansur

Graduate Theses, Dissertations, and Problem Reports (ETD)

Virtual reality (VR)-assisted learning may facilitate an immersive and interactive learning environment and enable learners to explore and interact with learning content at their own pace and interest. However, it is still unknown how well VR is received in engineering learning while empowering autonomy and personalization. The objective of this study is to investigate learners' perceptions of VR-assisted learning in engineering education while allowing learners to learn at their own pace, driven by their personal preference. To this end, experiments were conducted, in which thirty engineering students were recruited and immersed in a VR setting designed to deliver an interactive …

Utilizing Suas-Based Remote Sensing For Sustainable Outdoor Recreational Trail Design And Monitoring, Isaac C. Kinder

Graduate Theses, Dissertations, and Problem Reports (ETD)

This study utilizes sUAS-based remote sensing and hydrologic models to analyze and predict locations susceptible to water-based trail erosion. Erosion is frequently cited as the most significant environmental impact of trails and often requires costly design and management considerations. A professionally designed trail totaling 4 km in length was segmented based on presence or absence of water-based erosion for analyses and then flown with sUAS technology. Three Logistic regression (LR) models were generated utilizing several hydrologic terrain models of varying resolutions to determine the effects of spatial resolution on the models’ predictive accuracies. Receiver operator characteristics, kappa, and overall accuracy …

Evaluation Of 50’ Frp Truss Bridges With Timber Decks, Maxwell Browning Carey

Graduate Theses, Dissertations, and Problem Reports (ETD)

Fiber-reinforced polymer (FRP) composites have become mainstream structural materials and are being utilized in many different structural applications because of their outstanding thermos-mechanical properties and other characteristics. These characteristics include exceptional corrosion resistance, energy absorption, durability, high strength-to-weight, stiffness-to-weight ratios, and others. Also, FRP composites are cost effective especially when accounting for the service life of such a material.

In this study, testing and analysis were performed at both the component as well as a structural system levels. Herein, two FRP truss bridges of different widths with 50 ft. spans underwent extensive testing and analysis in accordance with AASHTO specifications. …

Enhancing Reservoir Modeling And Simulation Through Artificial Intelligence And Machine Learning: A Smart Proxy Modeling Approach, Andrew Timothy Jenkins

Graduate Theses, Dissertations, and Problem Reports (ETD)

The application of numerical reservoir simulation (NRS) has been a common approach within the oil and gas industry for decades, providing a means to model and forecast dynamic subsurface interactions, as a basis for reservoir management and development decisions. These techniques have expanded to application within carbon capture utilization and storage (CCUS) projects as domestic and global policy shift towards reducing carbon emissions while maintaining the energy needs of our modern society. NRS techniques have become a core process for permitting approval in Class VI (large-scale geological sequestration) wells due to the fundamental similarity of these types of subsurface processes. …

Advancing Gfrp Column Design: Strength, Effective Lengths, And Failure Modes, Jack Alan Wykle

Graduate Theses, Dissertations, and Problem Reports (ETD)

Glass fiber reinforced polymer (GFRP) composites have become an increasingly popular choice in construction industry due to their higher strength-to-weight ratio, ease of manufacture including lower Embodied Carbon Factor, and better durability in harsh environmental conditions than conventional structural construction materials. Currently, GFRP composite column design lacks well-established design standards due to the material's unique properties such as lower bending and shear stiffness than steel, differing compressive and tensile moduli, which leads to complexities in computing buckling capacities under local effects such as flange or web buckling and even torsional buckling under off-centered compression loading. Therefore, GFRP columns will behave …

Planar Semiconductor-Superconductor Topological Quantum Devices: Realistic Modeling Tools, Purna Prasad Paudel

Graduate Theses, Dissertations, and Problem Reports (ETD)

Planar semiconductor-superconductor (SM-SC) heterostructures hold significant promise for realizing topological superconductivity and hosting Majorana zero modes (MZMs) --- particle-hole symmetric quasiparticle excitations that emerge as localized zero-energy modes either at the edges of one-dimensional topological SCs or at the vortex cores of two-dimensional topological SCs. Due to their non-Abelian exchange statistics and topological protection, MZMs are prime candidates for constructing topological qubits and achieving fault-tolerant topological quantum computation. Despite notable progress, significant experimental and engineering challenges remain to realizing functional MZM-based qubits. One major challenge is the small topological gap achievable in these systems, rendering MZMs fragile against disorder. Additionally, …

Development Of Lab-On-A-Chip Platforms Incorporating A Novel Acoustic Atomization Induced Pump Based On A Vibrating Sharp Edge Capillary., Balapuwaduge Lihini Tharanga Catherine Mendis

Graduate Theses, Dissertations, and Problem Reports (ETD)

Capillary Vibrating Sharp-edge Ionization device (cVSSI device) was developed by our laboratory with a low cost and an easy fabrication procedure. The generation of small liquid droplets by this technique has been used as an ionization source for mass spectrometry analysis platforms. On usual applications incorporating the cVSSI device a syringe pump was connected to the back end of the vibrating sharp tip capillary to ensure continuous loading of sample into the capillary to sustain the ionization process at the tip end of the vibrating sharp tip capillary. We were able to observe that upon the generation of droplets the …

Dynamic Load Identification Using Optimal Sensor Placement And Dynamic Condensation Methods, Iole Pecora

Graduate Theses, Dissertations, and Problem Reports (ETD)

Knowledge of excitation loads that structures experience during their service life is pivotal in different engineering fields, not only from a structural design optimization point of view but also as prevention of possible damages to the structures themselves. However, in case of dynamic events such as tornadoes, structures subjected to impulsive load due to their vicinity of explosions, the excitation load cannot be directly determined through direct measurements. In these scenarios, the inverse problem is used, and it is called load identification. This type of problem tries to determine the excitation load knowing the system response through a series of …

Investigation Of Synergistic Effect Between Polystyrene And Polyethylene Under Conventional Thermal Heating And Microwave Heating, Thang Luong

Graduate Theses, Dissertations, and Problem Reports (ETD)

Single-use plastics (Low Density Polyethylene, LDPE; Polystyrene, PS; Polypropylene, PP) are increasingly used in the modern world, with their usage growing every year. An effective method to manage the resulting waste is urgently needed, as landfilling and incineration have proven harmful to the environment in the long term. Mechanical recycling may not maintain the desirable characteristics of the single-use plastics through several cycles. Pyrolysis emerges as a promising approach to address plastic waste. Given that single-use plastic waste often comes in a mixture, combining plastic in the feedstock is a viable solution to effectively convert these polymers altogether to gain …

Assessing Carbon Sequestration Of Mixed Hardwood Forests Through Optimizing Harvesting Strategies And Biomass Utilization For Biochar, Bibek Aryal

Graduate Theses, Dissertations, and Problem Reports (ETD)

This study investigated the long-term carbon stock of central Appalachian mixed hardwood forests under several harvesting strategies. The strategies were optimized to maximize both long-term carbon sequestration and timber supply during harvest using Mixed-Integer Linear Programming (MILP) models. Clear-cut (CC), Partial cut (PC), and mixed harvesting methods to unharvested conditions over 190 years were studied. Initially, harvested forests showed lower sequestration rates than unharvested forests but eventually surpassed them, with CC showing the highest rates over time. Younger forests, particularly those aged 85 to 130 years, exhibited peak carbon sequestration rates. Regarding carbon stock, the unharvested scenario initially had the …

Development Of Dynamic Mass-Energy-Thermodynamics Constrained Hybrid Neural Network Models For Process Systems Applications, Angan Mukherjee

Graduate Theses, Dissertations, and Problem Reports (ETD)

First-principles models can provide very good predictions even for cases when there are no data at all, or data are limited in certain range of operating conditions, or for cases where data collection is infeasible. However, the development of accurate first-principles models for complex nonlinear dynamic systems can be time consuming, computationally expensive, and may be infeasible for certain systems due to lack of sufficient knowledge (information). It is also challenging to adapt first-principles models for time-varying systems. Furthermore, it can be difficult, if not impossible, to develop accurate models for some complex phenomena that are poorly understood. On the …

Extracting Meaning: Museums, Power, And Shaping The Story Of Coal, Danielle Marie Petrak

Graduate Theses, Dissertations, and Problem Reports (ETD)

Organized into four case studies, this dissertation investigates how longstanding power relationships in the Central Appalachian coalfields have shaped the preservation and presentation of mining history at museums and historic sites. It contributes to scholarship in the fields of public history and Appalachian history by exploring how apolitical, noncritical, and biased narratives at mining history sites have obstructed the public’s acknowledgement of larger forces and systems that govern Appalachian society and often bring harm and misinformation to coalfield residents. To present more exhaustive, nuanced, and innovative interpretations of bituminous coal mining’s past and present, museums and historic sites must redirect …

An Approach For Robotic Pollination That Utilizes Imitation Learning, Ronald Michael Butts Ii

Graduate Theses, Dissertations, and Problem Reports (ETD)

The global decline in pollinator populations poses a significant threat to agriculture, motivating the development of robotic pollination systems. Previous works demonstrated successful robotic pollination of bramble flowers using visual servoing; however, pollination was limited to specific flower orientations. As such, the objective of this work is to develop a robotic pollination system that is capable of pollinating a wider range of orientations.

This research introduces an imitation learning-based framework for robotic pollination that positions the manipulator to view chosen flowers in specific orientations. The developed model leverages object detection (YOLOv8) to identify individual flowers and a convolutional neural network …

Political Agency In The Occupied House: Reconstructing Memory Through Squatter Resilience At Topf And Sons Historical Museum, Ebony Taylor Martin

Graduate Theses, Dissertations, and Problem Reports (ETD)

During the Holocaust the company of J.A Topf and Sons refocused their production to produce and improve a design for corpse incineration ovens. Their contributions streamlined the efficiency and performance of the death camps adding to the mounting death toll. Years after these evens the company grounds were abandoned and then given life again by a leftist youth movement. The squatter’s reinterpreted the history, led tours and utilized the grounds to create a third place for community, art and music. When the city decided to recognize the history of the company, the squatters were forcefully removed, and the building transformed …

Endogenous Glucocorticoid Signaling Is Required For Normal Macrophage Response To H. Pylori Infection, Stuti Khadka

Graduate Theses, Dissertations, and Problem Reports (ETD)

Gastric cancer is the fifth leading cause of cancer-related deaths worldwide, affecting millions of people. H. pylori is the strongest risk factor for gastric cancer, with about 90% of the cases strongly associated with H. pylori infection. Half of the world's population is infected with this bacterium. However, only a small subset of the infected population (1-3 %) go on to develop gastric cancer. Diagnosis of the disease at an early stage is the biggest challenge because of the widespread prevalence of H. pylori infection and a long asymptomatic phase before the advanced stages. Patients are left with limited treatment …

Dynamic Exchange-Correlation Functional For Bandgap Optimization: Reparametrization And Machine Learning, Viviana Faride Dovale Farelo

Graduate Theses, Dissertations, and Problem Reports (ETD)

This dissertation explores predicting the physical properties of solids using first-principles methods, with a focus on Density Functional Theory (DFT). DFT uses the electronic density within a material to predict its properties, simplifying the treatment of electron-electron interactions and allowing the study of realistic systems with a balanced treatment between accuracy and computational efficiency. Additionally, machine learning (ML) is employed to create correlations between some physical properties of solids and other properties or parameters that are more difficult to calculate.

The main problem addressed in this study is adjusting the parameters in the Strongly Constrained and Appropriately Normed (SCAN) semilocal …

Spiral Wave Teleportation And Multiplex Network Synchronization In Light Sensitive Belousov-Zhabotinsky Systems, Shannyn Alicia Tyler

Graduate Theses, Dissertations, and Problem Reports (ETD)

We experimentally and computationally investigate dynamical behaviors in excitable and oscillatory media using light sensitive Belousov-Zhabotinsky (BZ) systems. These systems are not in a state of thermodynamic equilibrium, and have been proven to show various interesting phenomena including spatiotemporal patterns, self-organization, and chaos. We utilize the BZ reaction, a nonlinear chemical reaction, known for its relaxation-type oscillations, to explore the dynamics of these systems.

We examine spiral wave teleportation in an excitable media as an effective alternate defibrillation method. Spiral waves have emerged as a key phenomenon associated with the initiation and persistence of cardiac arrhythmias. Using a light sensitive …

Cellular Level Changes Induced In Cancer Cells Due To Microgravity, Sai Deepika Reddy Yaram

Graduate Theses, Dissertations, and Problem Reports (ETD)

The increase in human activity in space has revealed several kinds of physiological challenges brought on by the absence of Earth's gravitational pull. NASA observed that during spaceflight, astronauts experience a 1-1.5% monthly loss in the mineral density of weight-bearing bones, with rehabilitation efforts on Earth often proving ineffective. This issue extends to muscles, the neuro vestibular system, the cardiovascular system, and vision. Cancer has emerged as a significant cause of mortality among astronauts, with studies up to 2017 showing that 41.3% of natural cause deaths among U.S. astronauts were due to cancer, primarily due to space radiation exposure. Cancer …

Investigation Of Space Charge Effects On Co2 Electrocatalytic Reduction On Gd-Doped Ceria Via Scanning Kelvin Probe And Model-Based Bayesian Analysis, Alejandro Mejia

Graduate Theses, Dissertations, and Problem Reports (ETD)

In studying novel energy conversion and storage systems, such as high-temperature electrolysis, numerous underlying fundamental physical processes remain unclear or inadequately understood. Among these, the modeling and comprehension of surface reaction mechanisms, coupled with the intricate effects of space‑charge interfaces, remains an unclear and challenging area of research.

The work of this dissertation involves the development of a 2D finite element analysis model, leveraging the robust MOOSE framework from INL. This model, featuring inhomogeneous defect thermodynamics for near-surface chemistry, formulated through Poisson‑Cahn variational theory, has been exploited for studying the electrocatalytic reduction of CO₂ on gadolinia doped ceria. The …

Data-Driven Modeling Of Oxygen Kinetics In La0.6sr0.4co0.2fe0.8o3−Δ (Lscf) For High-Temperature Reduction Of Co2 In An Electrolysis Cell, Ferron Campbell

Graduate Theses, Dissertations, and Problem Reports (ETD)

Electrolysis systems are critical to several societal applications, particularly energy storage and conversion. Developing these systems requires a detailed knowledge of the chemistry and thermodynamics of the materials used in the electrolysis cell. This work focuses on using embedded scientific machine learning as an efficient way to build an interpretable model for the reaction and transport kinetics in the LSCF electrode, whose performance directly influences the electrolysis system’s performance. The models developed in this study are trained using the publicly available machine learning package, FoKL-GP. This package incorporates a robust Gibbs sampler that employs a forward variable selection process to …

Enhancing Robotic Exploration Through Semantically-Guided Sampling Strategies, Christopher Alexander Arend Tatsch

Graduate Theses, Dissertations, and Problem Reports (ETD)

From space and deep-sea exploration to disaster response and environmental monitoring, autonomous robots are essential for advancing science, improving safety, and addressing critical challenges. This dissertation introduces a novel open-source strategy for autonomous robotic exploration: the Semantically-Guided Exploration (SGE) framework. Designed for ground vehicles, SGE integrates semantic understanding into the autonomous exploration process, improving decision-making in complex environments. Specifically, the proposed sampling-based approach uses the information from the semantic segmentation of RGB images and depth images to guide the robot's selection of exploration goals. This method enables the robot to steer away from potential dangers such as large rocks and …

Laser Deposition Additive Manufacturing Of Multi-Material And Metal-Ceramic Composite Structures, Manikanta Grandhi

Graduate Theses, Dissertations, and Problem Reports (ETD)

The increasing performance requirements of modern industrial systems, coupled with the imperative for decarbonization, necessitate a fundamental rethinking of metallic component design and manufacturing. Traditional materials, with their inherent limitations in property optimization, susceptibility to degradation, and weight constraints, are proving insufficient. Multi-material joining offers a potential solution, enabling designers to strategically integrate diverse materials with specific, tailored properties into single component. Functionally graded materials (FGMs) and oxide dispersion strengthened (ODS) materials are prime examples of this approach, delivering substantial improvements in wear resistance, thermal regulation, high-temperature resilience, and overall weight efficiency. However, conventional manufacturing approaches further exacerbate the limitations …

Triggered Online System Re-Identification Applied To Model Predictive Control Using Gaussian Processes, Daniel Augusto Kestering

Graduate Theses, Dissertations, and Problem Reports (ETD)

Safety, product quality, enhanced performance, and increased profit all depend on the control of chemical and energy processes. However, operational issues can lead to control challenges, especially when processes are subject to disturbances during their operation. Process control methods work best when processes operate close to their designed operat- ing conditions, but lack of performance or other issues may occur when the process is far from such conditions. To overcome these challenges, in this dissertation, online model re- identification is proposed for Model Predictive Control (MPC). This involves reassessing the predictive model of an advanced controller, namely MPC, when re-identification …

Dough Rheology And Its Influence On Sheeting Behavior, Najat Albarakati

Graduate Theses, Dissertations, and Problem Reports (ETD)

Dough is the starting material for a large number of baked products, including cookies, crackers and bread. In commercial food processing operations, it is desired to obtain the same product and with the same dimensions in a reproducible manner in order to minimize waste. In the case of dough, the flour used, and the nature and amount of ingredients employed depend on the specific product and the market served. This research was aimed at relating cracker dough rheology to sheeting behavior between two counter-rotating rollers. The sheet that is formed is used to punch out the crackers that are then …

Pathways To Health: Linking Accessible Green Space To Improved Health And Well‐Being In Rural Appalachia., Udday Shankur Datta

Graduate Theses, Dissertations, and Problem Reports (ETD)

Green spaces are essential for our physical health. The quality of its green space often determines the health of a community. The presence of green space in our lives is associated with reduced stress levels, better sleep, and increased feelings of safety. Lack of access to green space can lead to many health issues, such as high blood pressure, diabetes, and cardiovascular diseases, and has been linked to obesity and physical inactivity.

The Appalachian Regional Commission (ARC) defines Appalachia as a region covering 420 counties across 13 states in the eastern United States. A large part of this region is …

Novel Membrane Materials For Nutrient Recovery From Nutrient-Rich Resources, Km Prottoy Shariar Piash

Graduate Theses, Dissertations, and Problem Reports (ETD)

Global demand for fertilizer production is expanding substantially to meet the food demand of an increasing world population. Anaerobic digestate (AD) of various centralized wastewater facilities contains substantial amounts of ammonium (NH₄⁺) (300-800 mg/L), potassium (K⁺) (13-120 mg/L), and phosphorus (P) (30-100 mg/L)- based nutrients. In addition to reducing energy costs and CO₂ emissions compared to conventional fertilizing raw material manufacturing, recovering nutrients from these waste streams could help mitigate problems such as eutrophication, which otherwise incurs billions of dollars losses to US economy annually. Apart from nutrients, wastewater streams also contain organic pollutants …