Digital Commons Network^™

Application Of Machine Learning Techniques And The Unscented Kalman Filter To Real-Time Gas Turbine Clearance Prediction, Donald Earl Floyd

Theses and Dissertations

The growth in renewable energy sources and retirement of large baseload coal-fired power stations has led to an accompanying decrease in reliability and security of the electrical grid. Since renewable energy sources are typically non-dispatchable, this can lead to blackouts and/or brownouts for customers. Heavy duty gas turbine power plants (HDGT) offer a solution to this problem. HDGTs are dispatchable, clean, and offer flexibility in the fuel they consume, but operational limitations must be well understood to fully exploit their benefits.

One of the main operational limitations is the tip clearances in the gas turbine. In many cases, the gas …

The Study And Development Of Autonomous Scarf Repair For Composite Structures: A Focus On Advanced Air Mobility Vehicles, Stephen Hilton

Theses and Dissertations

“I’m sorry I haven’t been able to truly give you a solution to thermoplastic repair” – Arnt. Director GKN Global Tech Center, 2023

The aerospace industry has a prevalence of composite materials due to their outstanding benefits to the mechanical properties of structures while serving to reduce the overall structure weight. With the development of the Advanced Air Mobility market, there is an anticipated growth in the number of composite structures. Also, with the manufacturing environment of the 21st century, these composite structures are more and more being made using thermoplastic composites that can be recycled at the end of …

A Study Of Direct Sensitivity Method Solving Optimal Control Problems With Single And Multiple Time Grids With An Application In An Experimental Hybrid System, Hainan Wang

Theses and Dissertations

Computational methods for optimal control are important for dealing with bottlenecks in industries. By implementing optimal operation strategies obtained from the computational methods into dynamic systems, objectives such as saving energy, reducing cost, exploiting potential, and improving efficiency can be achieved. Computational methods for optimal control have been used in a broad range of disciplines, including aeronautics and astronautics, oil and chemical engineering, power systems, clean energy, biomedical engineering, economics, and management. Due to the great application value of optimal control, its computational methods have drawn worldwide attention. Direct methods are most effective in computational methods for optimal control. Direct …

Enhanced Two-Phase Heat Spreading Enabled By Dropwise Condensation, Kai Luo

Theses and Dissertations

The rapidly increasing power density of electronic systems has raised challenges for thermal management. Efficient heat spreading plays an important role in distributing high-density heat to the large-area heat sink and maintaining the junction temperature below the temperature limit during operation. Vapor chambers, a type of flat heat pipe utilizing two-phase heat transfer and fast travel of vapor flow, can achieve far more efficient two-dimensional heat spreading than most conduction-based thermal ground plane materials. By promoting dropwise condensation in vapor chambers, the thermal performance and scalability can be further improved due to the enhanced condensation heat transfer and unique droplet …

On The Use Of Cfd Modeling And Analytic Methods To Describe Pressure Drop In Highly Dense Structured Adsorbents In Gas Separation Processes And Fundamentals Of Adsorption, Ryan Timothy Sanders

Theses and Dissertations

The scope of this work can be divided into two main thrusts on topics found within adsorption. The first, and primary, topic is the use of CFD and analytical modeling to describe the flow of gas through a parallel, structured adsorbent channel which is described in Chapters 1 and 2. Chapter 1 establishes a non-experimental methodology based on using a 3D Navier-Stokes (NS) computational fluid dynamics (CFD) model in lieu of experiments, for developing 1D axial pressure drop correlations for structured adsorbents with parallel channels. Chapter 2 utilizes the methodology established in Chapter 1 in order to develop a new …

A Click Chemistry Amplified Nanopore Assay For High Performance Testing Of Protein Biomarkers In Diseases, Xiaoqin Wang

Theses and Dissertations

Nanopore detection technology enables nanometer-scale single-molecule detection, yielding valuable insights into analyte molecules' properties such as size, shape, charge, and concentration. Due to its label-free nature, high sensitivity, and real-time capabilities, it finds widespread application in genomics, proteomics, drug discovery, and environmental monitoring. Click chemistry, encompassing the attachment of a probe or substrate to a biomolecule, termed bioconjugation, features the copper-catalyzed azide-alkyne cycloaddition as a quintessential reaction, forming a 5-membered heteroatom ring. This study harnesses this reaction to craft single-strand DNA probes for nanopore testing, leveraging copper's catalytic properties for signal amplification. Host-guest reaction, a noncovalent bond between molecules, specifically …

Dual-Phase Membrane Reactor And Calcium Oxide-Based Sorbents For High-Temperature Carbon Capture, Utilization And Storage, Kangkang Zhang

Theses and Dissertations

Greenhouse gases, especially CO2 emissions, are responsible for global warming and the reduction of greenhouse gases is vitally important for the sustainability of our modern society. Currently, the most mature CO₂ capture, utilization and storage (CCUS) technology relies on flue gas “amine washing”, a costly and energy intense process that can negatively impact on the efficiency of existing power plants and the cost of electricity produced. Therefore, developing more efficient and cost-effective CCUS technologies is highly imperative. With the increasing production of natural gas in recent years, direct natural gas conversion into valuable chemicals also becomes more attractive than …

Simultaneous Crack & Wave Propagation And Acoustic Emission Signal Modelling Using Peri-Elastodynamic, Md Mushfiqur Rahman Fahim

Theses and Dissertations

This work presents the use of Peri-Elastodynamic, a guided wave simulation method based on meshfree non-local Peridynamics theory. To model simultaneous crack and wave propagation simulation and its application on Acoustic Emission (AE) signal modelling, a new formulation is presented. The field of nondestructive evaluation (NDE) and structural health monitoring (SHM) is slowly embracing the advancement in Machine Learning (ML) / Artificial Intelligence (AI) for better and cost-effective assessment of structures and damage prediction. AI/ML can revolutionize the NDE/SHM field by automating the data collection and analyzing processes. However, the big challenge is that the model needs a sheer amount …

Molecular Dynamics Simulation Insights Into Rejuvenating Aged Asphalt With Waste Soybean Oil And Polymers, Ke Shi, Feng Ma, Zhen Fu, Jenny Liu, Ruimeng Song, Dongdong Yuan, Yujie Tang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study utilized molecular dynamics simulations to assess the rejuvenation of aged asphalt (AA) with waste soybean oil (WSO) and functionalized SBS polymers, focusing on: 1) constructing and validating models for virgin asphalt (VA), AA, and composite rejuvenated asphalt with WSO and polymers; 2) analyzing diffusion effects and binding abilities in these rejuvenated models; 3) evaluating interface binding and diffusion behaviors in composite rejuvenated models. The addition of functionalized SBS molecules and WSO improved the diffusion rates of various components within these models. Specifically, functionalized linear-SBS (LSBS) molecules demonstrated superior diffusion performance compared to star-SBS (SSBS) molecules. Incorporating WSO and …

Fission Product Thermodynamics, Solubility, And Extraction In Molten Salts And Lead, Richard Lee Fitzhugh

Theses and Dissertations

Chemical behavior of fission products in systems relevant to two major advanced nuclear reactor systems, namely the lead-cooled fast reactor (LFR) and molten-salt reactor (MSR), has been studied with a heavy emphasis on thermodynamics. The behavior of fission products in molten salts is examined from a theoretical perspective, with an emphasis on the standard state used to define the thermodynamic activity. A standard state extrapolated from infinite dilution behavior, which is fairly common practice in electrochemistry, is found to facilitate faster, easier, and simpler analysis while retaining much of the accuracy of the complex Modified Quasichemical Model. Inductively-coupled plasma mass …

Void Formation During Liquid Composite Molding Under Varied Pressure With Mechanical Properties Validation, Neil Russell Thompson

Theses and Dissertations

Composite materials have revolutionized products and how they are manufactured. Most large-scale aerospace companies utilize a carbon fiber pre-impregnated with a resin in conjunction with an autoclave to minimize voids, but it is very expensive and requires a great amount of space. The less expensive alternative to prepreg-autoclave processes is known as Liquid Composite Molding (LCM), in which the resin is brought into a mold via overpressure on the resin supply or by a vacuum in the mold. But this process is more prone to voids due to bubble formation. Voids are a critical issue as common failure modes such …

Investigation Of The Cohesive Behavior Of Water-Intervened Rejuvenated Sbs-Modified Bitumen, Ke Shi, Feng Ma, Zhen Fu, Jenny Liu, Ruimeng Song, Dongdong Yuan, Yujie Tang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

When water interacts with bitumen, the diffusion and cohesion characteristics between the components of bitumen are negatively impacted. Molecular dynamics simulations were employed to construct various bitumen models, including bitumen–bitumen (without water), water-containing single bitumen, water-containing bitumen–bitumen, and bitumen–water–bitumen models. The primary research objectives were as follows: comparing the changes in the densities of bitumen models with and without water, analyzing the interlayer cohesive energies of bitumen models interacting with water, evaluating the hydrogen bonds in water-containing bitumen models, and characterizing the diffusion behaviors of bitumen components. The results indicated that when water interacted with the bitumen, it filled internal …

Quiescent Condensation Heat Transfer On Vertical Cicnt Structured Superhydrophobic Surfaces, Clint Mach Hubbard

Theses and Dissertations

This study experimentally investigates the impact of the subcooling magnitude, the carbon-infiltrated carbon nanotube (CICNT) diameter, the time duration of condensation, and amount of non-condensable gases on the nature of dropwise condensation and condensate removal, and heat flux and heat transfer coefficient measurements. Experiments were conducted in a vacuum chamber on a vertically oriented test CICNT surface. The CICNT diameter was varied between 15-120 nm and the subcooling ranged from 0.5-9 °C. Each test ran for a duration of at least one hour and video was recorded at 20-minute intervals. Three modes of condensation were observed: drop jumping, drop wetting …

Behavior Of Reinforced Lightweight Cellular Concrete Backfill For Mechanically Stabilized Earth Walls With Welded Wire Reinforcements, Cole Max Larsen

Theses and Dissertations

Lightweight cellular concrete (LCC) consists of a mixture of cement, water, and a pre-formed foam. The pre-formed foam entrains a high proportion of air voids into the cement water slurry at the time of casting, decreasing the product's overall weight. LCC is also a viable alternative when low native soil strengths prevent the use of traditional backfill methods through mitigating settlement and increasing strength. Due to these benefits, the use of LCC behind mechanically stabilized earth (MSE) walls is gaining popularity. Despite LCC gaining popularity behind MSE walls, the exact nature of the failure envelope is poorly understood. The pullout …

Tools For Planning Multi-Axis Vibration Qualification Tests, Marcus Edward Behling

Theses and Dissertations

Vibration qualification testing is necessary to ensure that components will endure vibration-induced damage in flight. Multi-axis tests have shown the potential for improvement over single-axis tests, though they require increased planning. This work focuses on planning three critical aspects of these tests: the amount of operational next assembly to include in the test, the size of shakers to use, and the number of shakers to use. Next assembly selection is studied by varying the amount of next assembly included in the lab test, performing physical tests, and comparing the accuracy of environment reconstruction in each test. In doing so, a …

Design For Pullout Resistance And Global Stability Of Metallic Reinforcements In Mse Walls With Lightweight Cellular Concrete Backfill, Joshua Curt Peterson

Theses and Dissertations

Lightweight cellular concrete (LCC) is a type of concrete that has reduced density and weight compared to traditional concrete. This is achieved by incorporating a large amount of air- filled cells or voids into the mixture. The resulting material is lighter, yet still possesses considerable strength and durability, making it suitable for a range of construction applications, especially in the case of retaining walls because of its reduced weight. Unlike traditional concrete, which can be extremely heavy and place significant stress on the supporting structure, lightweight cellular concrete reduces the pressure on the retaining wall, helping to prevent deformation and …

Utilization Of Sodium Flame Synthesis For The Formation And Deposition Of Pure Metal Materials For Applications In Additive Manufacturing, Zachariah Wargel

McKelvey School of Engineering Graduate Student Theses & Dissertations

Advanced material classes, such as high temperature alloys, ceramics, and refractory materials have become a key area of focus for expansion in the realm of additive manufacturing. Factors such as high melting points, material homogeneity, and physical properties such as ductility limit the application of popular additive manufacturing methods to these material classes. By utilizing sodium flame synthesis and deposition (SFD) technology, nanoparticle materials can be synthesized via combustion in a laminar co-flow diffusion burner and impacted such that the deposits can be used to manufacture designed components. By using the applicable precursor materials of metal chlorides and elemental sodium …

Demand Side Management Through Integrated Water Distribution Systems And Smart Irrigation Controllers, Nathan T. Lunstad

Theses and Dissertations

The innovation of electrical utilities in creating smart electrical grids has superseded that of water utilities in analogous efforts. While many water utilities are now using smart water technologies, they lack the virtual command center that allows for two-way communication for more effective forecasting, load balancing, preventive methods, emergency and master planning, and level of service delivery while ensuring environmental justice and enhancing the responsible use of resources. In this dissertation, I propose the idea of the Integrated Water Distribution System (IWDS) to overcome this challenge. IWDS coordinates management of water supply and demand in a way that benefits both …

Exploring Co-Manipulation Via A New Decomposition Of Interaction Force And An Exploration Of Signal Space In Multi-Agent Motion Primitives, Kody Blaine Shaw

Theses and Dissertations

Co-manipulation is when two or more people work together to move an object. In this work, we consider the physical co-manipulation of objects that are large and heavy enough that they are more easily handled by two or more participants. We currently lack a fundamental understanding of how people perform such tasks together, both the basic signals they use to communicate and how those signals are mapped to actions and behaviors. This work builds upon the existing body of knowledge to improve our understanding of physical co-manipulation. Specifically, interaction forces are often considered a key method for information transfer in …

Mechanochemical Correlations And Spatial Distribution Of Components In Plant Cell Walls And Extracellular Matrices, Huiyong Li

McKelvey School of Engineering Graduate Student Theses & Dissertations

Plant cell walls and extracellular matrices (ECMs) are important to cellular activities in plant/animal organs. The organization of plant cell wall/ECM components (e.g., local composition, arrangement, and ultrastructure of cell wall/ECM polymers) plays a role in determining their local mechanical properties. As a result, the natural processes of cell and tissue growth, development, and function rely on the control of cell wall/ECM composition, arrangement, and ultrastructure to manipulate local mechanical properties. However, directly correlating cell wall/ECM composition, organization, and mechanics has been challenging. To overcome this barrier, one goal of this thesis is to develop probing methodologies at a sub-cellular …

Designing Behavior-Aware Ai Systems To Influence Human Decision-Making, Guanghui Yu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Artificial intelligence (AI) demonstrates superiority over humans in many applications, such as image processing, speech recognition, and decision-making. AI systems are more efficient and accurate in information processing and computation, making them invaluable in assisting human decision-making across domains like healthcare, finance, and academia. Despite these strengths, real-world applications often involve complex, context-specific judgments and a deep understanding of human values, which current AI systems might not fully grasp. In domains requiring creativity and critical thinking, AI systems heavily rely on existing human knowledge. Humans, however, possess unique strengths such as intuition, which aids decision-making in uncertain or novel situations, …

Analysis Of Water Usage And Greenhouse Gas Emissions As Transition Fuel From Coal To Natural Gas In San Juan County, New Mexico, Tahereh Kookhaei

Civil Engineering ETDs

Abstract

Coal is a major contributor to various environmental issues, making the transition to alternative energy sources essential for reducing environmental impacts and combating climate change. San Juan County in New Mexico has historically depended on coal-fired power plants for producing electricity. However, due to environmental and economic pressures, there is a move to reassess energy strategies. This study explores the transition from coal to natural gas (NG) in San Juan County, with a focus on assessing changes in water usage and emissions (CO₂, NO_x, and SO₂) at the Four Corners (coal-fired) and Afton …

Tribological Analysis Of Heat Treatments On Medical Grade Cobalt Chromium Molybdenum Alloys, Samuel Edis Bowden

Theses and Dissertations

Cobalt chromium molybdenum (CoCrMo) has many material properties that make it desirable as a medical hip implant. Due to the range of heat treatments available and the resulting material properties that are present in medical device manufacturing using CoCrMo, many implants are not able to withstand both the chemical and physical wear necessary as a hip replacement. This research looks to examine various heat treatments and their resulting properties to find a desirable heat treatment for CoCrMo in hip implant bearing surfaces. This study was accomplished by using five distinct variations of heat treatment on forged CoCrMo alloy that would …

Domain Specific Aspect Extraction For Product Design, Divyam Sobti

Master's Theses

As technology advances, computers become increasingly proficient at interpreting and translating human language into machine-understandable text. With the help of algorithms in natural language processing (NLP), machines can now translate textual data. These algorithms help identify and extract specific text components known as aspects. The aspects represent specific attributes or topics within textual data. For instance, an Amazon review states,“ This phone has good battery life but poor camera quality,” and attributes like ‘battery life’ and ‘camera quality’ represent aspects in the text. Aspect extraction is a pivotal process involving identifying and isolating key features or topics within text. This …

Exploring The Link Between Travel Behavior And Mental Health, Emily Kae Youngs

Theses and Dissertations

This study explores the critical link between travel behavior and mental health, focusing on young adults who have expressed suicidal ideation. By analyzing how daily activities and movement patterns impact mental well being, the research aims to explore travel related mental health approaches for individuals. The importance of this work lies in its potential to improve the quality of life for individuals by informing more personalized and effective mental health strategies. Through comprehensive data analysis and statistical modeling, the research aims to uncover insights into how travel behavior influences motivation levels and mental well-being across different neurological and physiological groups. …

Effect Of Superabsorbent Polymer On 3d Printing Characteristics As Rheology-Modified Agent, Yu Cun Gu, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study aims to investigate the effects of two superabsorbent polymer (SAP) types, S1 and S2 (with continual absorption and rapid desorption, respectively) as rheology-modified agent on 3D printing characteristics. Three base mixtures were selected with different thixotropic behaviors (i.e., mixtures with high re-flocculation (τfloc), high structuration rate (Athix), and both low τfloc and Athix, respectively). The initial mini-slump flow of 190±10 mm was secured by adjusting superplasticizer (SP) or water demand (increasing w/b by either 0.025 or 0.05). An extrudable region was determined within the range of τfloc (200-890 Pa) and Athix (15-60 Pa/min). The use of the S2 …

Coupled Effect Of Fiber Type And Reinforcement Ratio On Flexural Behavior Of Reinforced Beams Cast With Super Workable Concrete, Jingjie Wei, Le Teng, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study investigated the effect of 5-dimensional hooked-end fiber (5D) on the structural performance of beams and compared its efficiency with other fibers in strengthening structural performance of reinforced concrete (RC) beams with an increase in reinforcement ratio (ρ). The potential of using fibers to reduce the longitudinal rebar based on various design criteria was investigated. The fibers included 5D, a combination of 80 % 3-dimensional hooked-end and 20 % short steel fibers (STST), and two combinations of macro synthetic fibers A and B (MSF). Experimental results indicated that, compared to non-fibrous beams, using 5D was the most efficient in …

Simulation Of Calcium Carbonate Nucleation Processes In Confined C-S-H Nanopores With Different Calcium-Silicon Ratios, Jiao Yu, Kerui Wang, Peixuan Yang, Mengmeng Li, Biqin Dong, Zuquan Jin, Shuxian Hong, Hongyan Ma

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Carbonation curing technology plays an important role in carbon cycling and improving the properties of cement-based materials, while the nucleation and growth mechanism of calcium carbonate (CaCO₃) is still unclear. Based on molecular dynamics simulation, the formation process and nucleation mechanism of CaCO₃ in confined C-S-H nanopores with different calcium-silicon ratios were studied. The results show that the clustering behavior of CaCO₃ in C-S-H nanopores filled with saturated CaCO₃ solution can be divided into three phases, rapid agglomeration stage, slow cluster stage, and stable cluster stage. The aggregation is mainly dependent on ionic bonding for …

Engineering Cell-Free Protein Synthesis Biosensors For Point Of Care Use, Tyler Jordan Free

Theses and Dissertations

Diagnostic tests can dramatically improve and save lives. Survival rates and patient outcomes related to cancer and other diseases can be improved when routine testing guides personalized treatment. Highly accurate laboratory tests exist for thousands of biomarkers, including those of interest in this dissertation, but cost and complexity limit access to life-saving lab tests in many cases throughout the world. To fill this need and increase accessibility of diagnostics, in this report we report our engineering advancements towards portable biosensors for colorimetric detection of glutamine, endocrine disrupting compounds (EDC), and pathogenic RNA which are key biomarkers in cancer treatment monitoring, …

Raw Data For M5h2r1 Origami Flasher Deployment Tests, Philip Klocke

ScholarsArchive Data

These data sets contain raw force data from the deployment tests of a case study origami Flasher.