Engineering Commons^™

Experimental Investigation Of The Long-Term Bending Deflection And Creep Performance Of Cross-Laminated Timber (Clt), Aaron Desantis

All Theses

Rising popularity in mass timber construction for residential and commercial projects has escalated the need to develop and increase understanding of mass timber products both from a strength and serviceability perspective. For cross-laminated timber (CLT) there is a significant lack of research on the creep characteristics also known as long-term deflection behavior. Creep is particularly important for products such as CLT that are used for floors with longer spans. Full-scale creep testing was conducted using 5-ply CLT panels over the course of 6 months in a controlled environment under dry service condition. Testing resulted in average final deflections 1.73 times …

Healthcare Built Environment And The Covid-19 Pandemic, A Mixed-Method Study, Mohammad Saleh Nikooopayan Tak

All Theses

The outbreak of COVID-19 presented an unparalleled risk to public health, leading to urgent scientific efforts in understanding transmission mechanisms and mitigating risks, especially in healthcare settings. This mixed-methods study examines knowledge advancement regarding indoor air quality in healthcare facilities during the pandemic. A systematic literature review of 163 post-COVID studies identifies key research thrusts and 31 recommendations related to building ventilation, air filtration, surface disinfection, and monitoring. Comparison with over 200 pre-pandemic publications reveals both reliance on established infection control principles and unique contributions, such as detecting viral RNA in air and surface samples indicating potential airborne and fomite …

The Effects Of Compression Wrapping Techniques And Primary Wound Dressings On Leg Skin Interface Pressure, James Cox

All Theses

Peripheral edema affects approximately 20% of people in the US over the age of 50 and is frequently encountered among individuals with conditions such as heart disease, prolonged immobility, and venous insufficiency.¹ Compression is an established therapeutic tool utilized for the management of several chronic edema presentations including lymphedema and venous leg ulcers.^2,3 Therapeutic efficacy of compressive applications can be evaluated by defining interface pressure (IP) and IP distributions associated with specific textile combinations.² During compressive applications where an open wound is present, primary wound dressings should be used in combination with compressive wraps. Primary wound dressings …

The Effect Of Package Types On Fresh Peaches In The Direct-To-Consumer Distribution Environment, Brennan Lytle

All Theses

The direct-to-consumer (DTC) shipping mode presents new opportunity for fresh peach sales in North America where demand over the past four decades has steadily declined. The hazards in this distribution mode are severe, and fresh peaches are fragile emphasizing the need for proper protection. A full analysis that not only encompasses the effects of the direct-to-consumer distribution environment, but also incorporates analyses of the environmental and economic impact of the packages utilized for transit of peaches is necessary. In this study, we use the metrics of peach grade, firmness, soluble solids concentration, and percent softness before and after the distribution …

Dataset Of Single And Double Faults Scenarios Using Vibration Signals From A Rotary Machine, Larry Marshall, David Jensen

Mechanical Engineering Faculty Publications and Presentations

This dataset includes vibration sensor data from accelerometers located on the support bearings on a rotary machine designed as a fault simulator. Data collection for known faulty components include: bearing inner and outer raceway faults and bent shaft. 38 singles and double fault scenarios and a one no fault scenario were collected at three different operating frequencies (shaft rpm). Data was collected for approximately 10 seconds per scenario at a rate of 6400 hertz. Data can be used for machine learning classification.

In Vitro And In Vivo Diabetic Models For Assessment Of Tissue Engineered Vascular Grafts, Juan Carlos Carrillo Garcia

All Dissertations

Diabetes has become one of the leading causes of lower-limb loss worldwide. Every 30 seconds, a person loses a limb due to diabetic-related vascular complications. About one-third of patients needing lower-limb bypass surgery have debilitated autologous vessels unsuitable for use, and no other good long-term options are available. These detrimental effects on the vasculature are caused mainly by the hyperglycemic and hyperlipidemic conditions derived from diabetes. Under these conditions, an increase in advanced glycation end products (AGEs) and reactive oxygen species leads to irreversible crosslinks of extracellular matrix proteins, accelerating vascular pathology through vascular stiffening, endothelial dysfunction, inflammation, atherosclerosis, fibrosis, …

Accurate Orientation Control Of Tendon Driven Continuum Robots That Exhibit Elasticity, Manu Srivastava

All Dissertations

This dissertation makes new contributions to the modeling and implementation of Tendon Driven Continuum Robots (TDCRs). Specifically, motivated by 3D printing of concrete using a continuum hose robot in construction applications, we focus on TDCRs featuring compliance in the robot backbone and actuating tendons, e.g. surgical robots/endoscopes/catheters with tendon actuation. We expand previous mechanics-based models to show how and why such compliance significantly restricts performance when traditional kinematics-based planning and control techniques are applied.

The main contribution of this work is a new Elasticity Compensation(EC) model that explains why the ad hoc approach of preloading/pretensioning the tendons compensates for compliance …

Bio-Methane Production From Anaerobic Co-Digestion Of Poultry Litter With Wheat Straw Improved By Process Optimization And Employment Of Advanced Techniques, Yuanhang Zhan

Graduate Theses and Dissertations

Anaerobic co-digestion (Co-AD) of poultry litter (PL) and wheat straw (WS) for sustainable waste management and simultaneously renewable bioenergy generation was improved by advanced technologies including micro-aeration (MA), biochar addition (BC), nanoparticles supplementation (NP) and their integrations. Response surface methodology (RSM) and artificial neural network (ANN) were used for the process modeling and optimization. First, a method by gradually increasing OLR was developed for the start-up of Co-AD of PL and WS in an anaerobic sequencing batch reactor (ASBR), with a continuous daily biogas production of (13.06 ± 0.21) L and methane content (MC) of (54.38 ± 0.53) % observed. …

Fabrication And Measurement Of Lt-Gaas Photoconductive Antennas And Arrays, Zachary Paul Uttley

Graduate Theses and Dissertations

This thesis presents the fabrication and measurement of LT-GaAs based terahertz (THz) photo conductive antennas (PCAs) and arrays. The LT-GaAs THz PCAs are fabricated to serve as reference devices to new 2D material black phosphorous (BP) based THz PCAs. The LT-GaAs and BP devices have identical metallic electrodes, allowing for a comparison of emitted THz intensity and bandwidth. All PCAs have been measured using an open bench pulsed time-domain spectroscopy (TDS) system with a usable bandwidth from 0.1-4 THz, pumped with a 780nm Ti:Sapphire femtosecond laser. The results have shown LT-GaAs devices outperforming BP devices in signal amplitude and bandwidth …

Achieving High Renewable Energy Integration In Smart Grids With Machine Learning, Yaze Li

Graduate Theses and Dissertations

The integration of high levels of renewable energy into smart grids is crucial for achieving a sustainable and efficient energy infrastructure. However, this integration presents significant technical and operational challenges due to the intermittent nature and inherent uncertainty of renewable energy sources (RES). Therefore, the energy storage system (ESS) has always been bound to renewable energy, and its charge and discharge control has become an important part of the integration. The addition of RES and ESS comes with their complex control, communication, and monitor capabilities, which also makes the grid more vulnerable to attacks, brings new challenges to the cybersecurity. …

Double-Sided Cooled Power Modules For Electric Vehicles, Riya Paul

Graduate Theses and Dissertations

Double-sided cooled (DSC) power modules in conjunction with Silicon Carbide (SiC) power devices are expected to significantly elevate the performance of the next-generation electric vehicle power inverters. The double-sided cooling enables maximum heat dissipation, resulting in higher power density. SiC power devices, with their fast-switching speeds, reduce the power losses for higher efficiency. A half-bridge power module consisting of 13 mΩ 1.2 kV SiC devices is used for this work. A baseline DSC power module was designed, fabricated, and tested. This unique design uses truncated rectangular copper connection blocks for better heat dissipation from the device top side compared to …

Partial Discharge Mitigation In Power Modules Using An Automation-Driven Design Rule Development Method, Shilpi Mukherjee

Graduate Theses and Dissertations

Power modules used for the conversion and conditioning of electrical power for applications like electric vehicles, more-electric aircraft, the power grid, etc., are largely designed manually by engineers. Design automation of power modules is starting to gain recognition as a timely and necessary alternative to intuitive manual design and fabrication. With increasing need for wide bandgap materials that can operate at higher voltages, and the need to make modules more compact, hazards like electrical breakdown are more likely. Partial discharge (PD) is a silent and invisible precursor to electrical breakdown. It is compounded with compaction, creating a potential for electrical …

A Real-Time Anpc Inverter Digital Twin With Integrated Design-For-Trust, Paulo Vitor Do Amaral Custodio

Graduate Theses and Dissertations

The demand for renewable energy has increased over the last few years, and so has the demand for greater expectations within the energy market. This increasing trend has been accompanied by more significant usage of internet-connected devices (IoT), leading to critical electrical infrastructure being connected to the internet. Implementing internet connectivity with such devices and systems provides benefits such as improving the system's performance, facilitating irregularity and anomaly mitigation, and providing additional situational awareness for enhanced decision-making. However, enhancing the connected system with IoT introduces a drawback – a greater vulnerability to cyber-attacks. Cyber-attacks targeting critical infrastructure in the electrical …

Generalization Through Diversity: Improving Unsupervised Environment Design, Wenjun Li, Pradeep Varakantham, Dexun Li

Research Collection School Of Computing and Information Systems

Agent decision making using Reinforcement Learning (RL) heavily relies on either a model or simulator of the environment (e.g., moving in an 8x8 maze with three rooms, playing Chess on an 8x8 board). Due to this dependence, small changes in the environment (e.g., positions of obstacles in the maze, size of the board) can severely affect the effectiveness of the policy learned by the agent. To that end, existing work has proposed training RL agents on an adaptive curriculum of environments (generated automatically) to improve performance on out-of-distribution (OOD) test scenarios. Specifically, existing research has employed the potential for the …

Grasp Based Metaheuristic To Solve The Mixed Fleet E-Waste Collection Route Planning Problem, Aldy Gunawan, Dang V.A. Nguyen, Pham K.M. Nguyen, Pieter. Vansteenwegen

Research Collection School Of Computing and Information Systems

The digital economy has brought significant advancements in electronic devices, increasing convenience and comfort in people’s lives. However, this progress has also led to a shorter life cycle for these devices due to rapid advancements in hardware and software technology. As a result, e-waste collection and recycling have become vital for protecting the environment and people’s health. From the operations research perspective, the e-waste collection problem can be modeled as the Heterogeneous Vehicle Routing Problem with Multiple Time Windows (HVRP-MTW). This study proposes a metaheuristic based on the Greedy Randomized Adaptive Search Procedure complemented by Path Relinking (GRASP-PR) to solve …

Mitigate The Flood Risk At The Parking Lots At The University Of Texas Rio Grande Valley - Edinburg Campus, Mishell Carolina Mazon

Theses and Dissertations

This study focuses on the analysis of the drainage system in the parking lots of the Edinburg campus of the University of Texas Rio Grande Valley. The current project will use the rational method and modified rational method described in the Texas Department of Transportation manual to analyze and determine a solution for the current built drainage system. The primary objective of this study is to offer a practical and comprehensive solution to address the issue of this area that has flooded during heavy rainfall storm events. The proposed solution takes into consideration the building codes of the city of …

Nrc-Sim: A Node-Red Based Multi-Level, Many-Core Cache Simulator, Ezequiel Treviño

Theses and Dissertations

As computational systems become ever-more integral to daily life, so too does the importance of understanding how these complex systems work. For those unfamiliar with the underlying concepts, this can be a daunting task. In an effort to address such concerns, this paper presents a Node-RED based cache simulator that enables users to observe the effects of their desired cache configuration, with users having the ability to easily modify various parameters, such as the core count, the number of levels within the cache, and coherence protocols, among other parameters. Through the use of Node-RED, NRC-SIM allows for simplicity of use …

A Hybrid Lateral Flow Sand Filter Wastewater Treatment System: An Evaluation On The Treatment And Disposal Capabilities Of A Modified Sand Filter, Harry Mccaskill Iv

Graduate Theses and Dissertations (2019 - present)

Decentralized wastewater treatment exists primarily in suburban and rural areas where centralized treatment is not an option. Traditional on-site treatment systems usually include the use of a septic tank and a drain field. This orthodox method works well when implemented into environments that are accommodating for the infiltration of effluents, and thus allowing for soil treatment. Unfortunately, there are some circumstances that prevent traditional systems from working such as impermeable soil conditions. The Wastewater Treatment System analyzed in this thesis was created to overcome such inhospitable environments. More specifically, this system is catered towards the rural residences of The Alabama …

Comparison Of Random Coupling Model To Stochastic Dyadic Green’S Function When Coupling To A Distributed Port, Evelyn Anne Dohme

Electrical and Computer Engineering ETDs

The Random Coupling Model (RCM) provides statistical representation of coupling between ports in a highly overmoded resonant cavity based on knowledge of radiation impedances of system ports and cavity properties. A recent variant of RCM, the Stochastic Dyadic Green’s Functions (S-DGF), provides the statistical distribution of fields in the cavity. By using Source Reconstruction Methods (SRM) to approximate equivalent surface currents, I hypothesized that the S-DGF can calculate the fields at their location, enabling a statistical estimate of the coupled power. Using nearfield radiation from simple patch antenna simulations and the SRM to estimate the equivalent fields and account for …

Modeling And Validating Temporal Rules With Semantic Petri Net For Digital Twins, Han Liu, Xiaoyu Song, Ge Gao, Hehua Zhang, Yu-Shen Liu, Ming Gu

Electrical and Computer Engineering Faculty Publications and Presentations

Semantic rule checking on RDFS/OWL data has been widely used in the construction industry. At present, semantic rule checking is mainly performed on static models. There are still challenges in integrating temporal models and semantic models for combined rule checking. In this paper, Semantic Petri-Net (SPN) is proposed as a novel temporal modeling and validating method, which implements the states and transitions of the Colored Petri-Net directly based on RDFS and SPARQL, and realizes two-way sharing of knowledge between domain semantic webs and temporal models in the runtime. Several cases are provided to demonstrate the possible applications in digital twins …

Energy-Aware Coordination Of Automated Vehicles, Nathan Goulet

All Dissertations

Energy is an inherently limited resource for two reasons: the sources utilized to obtain energy are limited; and the methods used most often to convert energy also generate pollutants that the planet has a limited capacity to absorb or compensate for without adverse effects. Efficiently utilizing energy is, therefore, an important topic. As around 16% of the energy consumed in the United States is by light vehicles, a significant impact can be made if vehicle energy consumption is reduced. The advent of connected and automated vehicles offers unprecedented opportunities to optimize their behavior with respect to energy consumption through trajectory …

Applications Of Large Eddy Simulations To Novel Internal Combustion Concepts, Patrick O'Donnell

All Dissertations

Computational fluid dynamics (CFD) simulations of internal combustion engines (ICEs) are becoming an increasingly popular tool in the automotive industry to either explain experimentally observed trends or perform lower cost design iterations. The convenience of commercially available CFD software and advancements made in computing hardware have been the impetus behind this growing popularity. However, obtaining accurate results using these software packages is not a trivial process and requires an in-depth understanding of the underlying numerical methodology and sub models for various physical phenomena. Specific to the ICEs, CFD simulation often entails the use of models for detailed chemistry and combustion, …

Improved Vehicle-Bridge Interaction Modeling And Automation Of Bridge System Identification Techniques, Omar Abuodeh

All Dissertations

The Federal Highway Administration (FHWA) recognizes the necessity for cost-effective and practical system identification (SI) techniques within structural health monitoring (SHM) frameworks for asset management applications. Indirect health monitoring (IHM), a promising SHM approach, utilizes accelerometer-equipped vehicles to measure bridge modal properties (e.g., natural frequencies, damping ratios, mode shapes) through bridge vibration data to assess the bridge's condition. However, engineers and researchers often encounter noise from road roughness, environmental factors, and vehicular components in collected vehicle signals. This noise contaminates the vehicle signal with spurious modes corresponding to stochastic frequencies, impacting damage monitoring assessments. Thus, an efficient and reliable SI …

Variability In Anesthesia And Its Implications For Improving Patient Safety, Joshua Michael Biro

All Dissertations

Improving patient safety in anesthesia has proven to be an arduous and challenging task. Despite the many strategies and interventions to improve patient safety that have been employed, patient harm in anesthesia remains a problem. The struggle to reduce patient harm in anesthesia is both attributable to and representative of the complexity of the anesthesia system. In navigating this complex system, anesthesia providers have different approaches to how they accomplish their work, which results in variability in anesthesia practice. This variability provides an immense challenge to designing and implementing efforts to improve patient safety, as rigid interventions are often met …

Protein A And Multimodal Anion-Exchange Membrane Adsorbers For Downstream Purification Of Therapeutic Biomolecules, Joshua Osuofa

All Dissertations

This dissertation explores development and characterization of membrane chromatography tools for downstream purification of therapeutic biomolecules. Convective technologies, particularly membrane chromatography, are emerging in the field of bioseparations as an alternative to resin chromatography due to their improved throughput capability. On the forefront of emerging membrane technologies are multimodal and Protein A membrane adsorbers. The overarching theme of this dissertation research was to investigate advances in these membrane chromatography tools. The primary objective was to develop and characterize novel Protein A membrane adsorbers. A secondary objective was to characterize newly commercialized Protein A and multimodal anion exchange membrane adsorbers.

Two …

Examining The Influence Of The Classroom Environment On Motivation, Belonging, And Academic Confidence In Engineering Education: A Relational Developmental Systems Approach, Robert O'Hara

All Dissertations

This dissertation explores the impact of the classroom environment on undergraduate engineering students by integrating three manuscripts using the process-person-context-time (PPCT) model within Bioecological Systems Theory. Each manuscript focused on students’ sense of belonging, motivation, and academic confidence. The study confirms prior research suggesting a link between students' perceptions of the environment and their sense of belonging, motivation, and academic confidence. The findings highlight the complex nature of student and classroom environment relationships throughout their college experience. Moreover, the results are demonstrated across different engineering majors. Overall, this dissertation highlights the significance of understanding the complex interactions between students and …

Investigation Of Vo2 Thin Films And Devices For Opto-Electromechanical Applications, Samee Azad

All Dissertations

Specialized and optimized low pressure direct oxidation technique have been implemented to synthesize high quality VO₂ thin films on various substrates (sapphire, SiO₂/Si, AT-cut quartz, GaN/AlGaN/GaN/Si and muscovite). Structural and surface characterization methods such as X-ray diffraction, Raman spectroscopy and atomic force microscopy have been administered on the grown VO₂ films which indicate their material quality. Transition of characteristics of the VO₂ films are caused by semiconductor metal transition (SMT). This phenomenon is attributed as the change maker in transition of resistivity and transmitted optical power through the VO₂ films. Apart the substrates mentioned, …

High-Energy Storm Events And Their Impacts On Carbon Storage In Tidal Wetlands Of South Carolina, Gavin Gleasman

All Dissertations

Atmospheric carbon dioxide (CO₂) concentrations have been increasing at an accelerating rate for the past two centuries, profoundly impacting global climate change. Atmospheric CO₂ concentrations are influenced by the global carbon cycle through physical and biogeochemical pathways. Tidal wetland environments play a vital role in the global carbon cycle by offsetting atmospheric CO₂ concentrations through their natural physiochemical processes of high autotrophic productivity, allochthonous organic matter deposition, anoxic soils, and continuous accretion which promotes carbon sequestration with long-term storage at the land-ocean margin. The Intergovernmental Panel on Climate Change (IPCC) and United States Global Change Research …

Vibration-Based Fault Diagnostics In Wind Turbine Gearboxes Using Machine Learning, Abdelrahman Amin

All Dissertations

A significantly increased production of wind energy offers a path to achieve the goals of green energy policies in the United States and other countries. However, failures in wind turbines and specifically their gearboxes are higher due to their operation in unpredictable wind conditions that result in downtime and losses. Early detection of faults in wind turbines will greatly increase their reliability and commercial feasibility. Recently, data-driven fault diagnosis techniques based on deep learning have gained significant attention due to their powerful feature learning capabilities. Nonetheless, diagnosing faults in wind turbines operating under varying conditions poses a major challenge. Signal …

Processing, Microstructure, And Properties Of Alumina Ceramics And Silica Glass During Laser Selective Additive/Subtractive Manufacturing, Xiao Geng

All Dissertations

The heterogeneous structure is essential to obtain excellent performance in many ceramics or glass devices/components. Conventional fabrication on these heterogeneous structure composites usually requires multiple treatments, specific molds for certain structures, and post-processing to get desired structure and properties. Therefore, the flexibility of the structure is limited, and a long fabrication time is required.

Integrated additive/subtractive manufacturing and laser-based technologies have caught researchers` attention in ceramics/glass heterogeneous structure fabrication. This is because the integration of additive manufacturing (AM) with subtractive manufacturing (SM) not only maintained the advantages of AM in rapid prototyping, design complexity, and reduced material wastage but also …