Engineering Commons^™

Comparative Analysis Of The Effects Of Post Processing On The Flexural Fatigue Endurance Of Additively Manufactured Ti-6al-4v, Cristian Banuelos

Open Access Theses & Dissertations

This study delves into analyzing the effects of various machining techniques on the flexural fatigue life of Ti-6Al-4V L-PBF specimens. The fatigue life and fracture behavior of specimens subjected to milling, grinding, polishing, and abrasive media blasting were compared. The findings reveal significant differences in the fatigue resistance between machined and non-machined parts. This study contributes to the understanding of the effects of post-processing on the durability of L-PBF manufactured components, offering insights for enhancing their application in critical aerospace and biomedical applications.

A Methodology For Determining Optimal Milling Parameters For Low-Taper Microtensile Sample Production, Zachary Wayne Barker

Open Access Theses & Dissertations

Femtosecond lasers are beginning to see an increase in interest for industrial and high throughput microsample milling applications. Despite this, much of the literature regarding removal rate studies for ultrashort pulse laser milling continues to focus on single-pulse or similar experiments that have a very small time on target. The material volume removal rates of femtosecond milling can vary wildly depending on parameters like laser scan speed, hatch spacing, z-axis step size, and pulses on the material. Currently, there is no established methodology for determining the optimal values of these parameters for micromilling applications. This methodology was developed in this …

Sulfonated Polyethersulfone Membranes For Electrodialysis Desalination And The Influence Of Solvent Evaporation On Current Efficiency, Salinity Reduction, And Permselectivity, Li Chen

Open Access Theses & Dissertations

The high cost of ion exchange membranes significantly limits the public application of electrodialysis. The research of novel, inexpensive ion exchange membranes is essential to developing and applying electrodialysis desalination technology. This research focuses on fabricating cation exchange membranes with polyethersulfone (PES) and sulfonated PES (sPES) for water treatment. N-Methyl-2-Pyrrolidone (NMP) was used as an organic solvent to dissolve PES. After different solvent evaporation times were optimized from 0 hr to 24 hr, those membranes were formed through the phase inversion technique. The performance results show that the PES membranes performed the best when the solvent evaporated at 3 hr, …

Effect Of The Microstructure On The Corrosion Behavior Of Alcunimn And Alcunimnsi High Entropy Alloys In A 3.5wt% Nacl Solution, Celine Chiong

Open Access Theses & Dissertations

In this study, the AlCuNiMn and AlCuNiMnSi high entropy alloys (HEAs) are investigated to characterize the effect of Si addition and subsequent annealing treatments on the corrosion behavior in a 3.5wt% NaCl solution at room temperature. The microstructure evolution from the as-received condition and after annealing at 600°C, 800°C, and 1000°C for 24 hours in air is examined. The microstructural transformation of HEAs is extensively reported in the literature. However, its impact on the corrosion resistance of HEAs has not received the same attention. In this study, an increase in the annealing temperature of the base AlCuNiMn alloy improved the …

Using Genetic Algorithm And Geographic Information System For Equity-Driven Transportation Planning And Analysis, Emiliano Del Rio Reyes

Open Access Theses & Dissertations

Efforts to address equitable access in public transit planning have gained momentum, spurred by incentives for Metropolitan Planning Organizations (MPOs) and State Departments of Transportation (DOTs). However, traditional strategies often fall short of meeting the needs of disadvantaged communities, particularly in underserved areas. This study presents a pioneering methodology leveraging Genetic Algorithms (GA) and Geographic Information Systems (GIS) to optimize bus stop placement, aiming to enhance equitable access in public transit systems. Focusing on Route 16 of Sun Metro in El Paso, Texasâ??a critical feeder route linking the Westside Transit Center to Upper Valley neighborhoodsâ??the research commences with a comprehensive …

Biofabrication Of Human Tissue-On-A-Chip Models Using Engineered Biocompatible Electrospun Scaffolds, Zayra Naomi Dorado

Open Access Theses & Dissertations

This study explored the adoption of furfuryl gelatin (F-gelatin) based electrospun scaffolds compared with poly-caprolactone (PCL) as promising biomaterials for tissue engineering applications. Tissue-on-a-chip models, incorporating F-gelatin and PCL electrospun scaffolds, offer promising avenues for healthy and disease-in-vitro tissue models that can be explored to investigate underlying physiological mechanisms involved in disease development. Previous research has demonstrated the cytocompatibility of F-gelatin when used for modifying implant surfaces and tissue repair applications [1]. Our earlier published works have also successfully utilized F-gelatin for in-vitro cardiac tissue engineering [2][3]. We designed F-gelatin and PCL electrospun scaffolds to replicate the native tissue extracellular …

Relations Between Printability And Rheology In A Ceramic Paste Extrusion Process, Nicholas Durand

Open Access Theses & Dissertations

Ceramic additive manufacturing (AM) uses the same fundamentals as material extrusion (MEX) that utilizes polymers or resins for printing applications. Ceramic AM uses the same process of slicing an STL file to determine a toolpath for the printer that will facilitate material deposition to manufacture full parts; ceramic AM also provides a low-cost advantage when compared to processes that require high powered lasers for melting metal powders or heated nozzles used for dispensing thermoplastics. Despite having the similar design freedom and ability for rapid prototyping that other printing methods benefit from with the addition of low cost, ceramic AM has …

Laser Powder Directed Energy Deposition (Lp-Ded) Inconel 718: Laser Power And Heat Treatment Effect On Microstructure And Mechanical Properties, Dana Victoria Godinez

Open Access Theses & Dissertations

This study examines the microstructure and mechanical properties (tensile, hardness, and fatigue endurance) of laser powder-directed energy deposition (LP-DED) printed specimens with varying deposition parameters. Five samples with power inputs ranging from 350 to 2620W, all of similar thicknesses, were evaluated to enable a direct comparison. The varying specimens were heat treated, including stress relief, hot isostatic pressing, solution, and two-step aging. The resulting microstructures and their corresponding hardness values were compared at each heat treatment stage. The fully heat-treated specimens' tensile properties and fatigue life were also examined and compared. Key findings of this study indicate that complete heat …

Feasibility Study For The Detection Of Damage To Composite Overwrapped Pressure Vessels With Phase Array Ultrasonic Testing, Jordan Scott Hitter

Open Access Theses & Dissertations

When discussing the field of Nondestructive Examination, there are various techniques and instrumentation that can be utilized for analysis of components. However, with newer technology and the development of newer forms of technique, it is critical to explore exactly how these can be applied. This work will aim to explore one newer technique, Phased Array Ultrasonic Testing, and determine the viability of its use for examining Composite Overwrapped Pressure Vessels (COPVs). Currently, the types of vessels have been used in a variety of ways such as in transportation vehicles. More notably, these vessels are used in aerospace applications hence the …

Development Of A Digital Engineering Testing Framework For Cubesat Applications, Javier Alberto Martell

Open Access Theses & Dissertations

Digital Engineering (DE) is playing an important and expanded role in todayâ??s industry. As engineering systems become more and more complex with each new iteration, the need for a more efficient and agile methodology for project management and development is needed. The SleeperSat-1 (SPST-1) is a Modular Open System Architecture (MOSA) type of small satellite being developed by the UTEP Aerospace Center. The SPST-1 will mostly use digital engineering tools for its lifecycle research and development. CubeSats require rigorous environmental testing not only to ensure the success of the mission, but also to ensure the safety of the crew, space …

Microwave Emission Model Parameter Tuning For Surface Soil Moisture Retrieval Using Uav-Mounted Dual Polarization L-Band Radiometer, Santiago Hoyos Echeverri

Open Access Theses & Dissertations

Surface soil moisture retrieval from L-band brightness temperature has been developed for the past decades due to multiple beneficial characteristics of 1-2 GHz frequency bands for remote sensing of the environment. Numerous microwave emission models have been proposed for tower and satellite-based operations with successful retrieval of surface soil moisture and vegetation water content. As a result of the development of cost-effective and low-mass microwave L-band radiometers such as the Portable L-band Radiometer (PoLRa), surface soil moisture surveying traditionally developed by satellite missions SMOS and SMAP can now be developed at local scales, bringing these operations to commercial small unmanned …

Microstructural Characterization And Oxidation Behavior Of Al-Cu-Ni-Mn And Al-Cu-Ni-Mn-Si Non-Body Centered Cubic High Entropy Alloys, Mckenna Mae Lin Hitter

Open Access Theses & Dissertations

High entropy alloys (HEA) differ from traditional alloying systems because five elements are mixed in equi-atomic proportions, as opposed to having one main principal element. As a result of exploring this new method of alloying, it was found that high entropy alloys demonstrate exceptional mechanical properties, an example being oxidation resistance, and are capable of enduring elevated temperatures. Seeing the potential that this new area of interest contains, studies involving a combination of elements to form various HEA have been performed. Most refractory metals are body-centered cubic and possess extremely high melting temperatures, so they are regularly considered when designing …

Analysis Of Drying Behavior Of Robocasted Barium Titanate, Abigail Ortega

Open Access Theses & Dissertations

Finding an adequate ceramic formulation for material extrusion is a time-consuming process. The necessary equipment may be unavailable to perform the desired test. This study demonstrated an alternative to observe a material after extrusion to understand its drying process. This study focused on 55 solid loading volume percent and a 39 solid loading volume percent, each with two different binder treatments focusing on fresh same day made binder, a 30 day old, aged binder and lastly an artificial binder obtained by a fuming process. Firstly, a formulation was created and loaded onto a pressure-based syringe to be extruded with a …

Energy Optimization In Pneumatic Systems Using Ens-200 Energy Saving Trainer, Maha Guru Shankar Perumal

Open Access Theses & Dissertations

Various industries such as manufacturing and assembly, the automotive sector, printing and paper handling, packaging, aerospace, etc., widely use pneumatic systems for a variety of operations. Enterprises use pneumatic systems for cost-effectiveness, reliability, and simplicity. However, they also have certain inefficiencies, leading to high operating costs and reduced efficiency in various applications. The focus of this research is on energy optimization in pneumatic systems to improve efficiency in industrial applications, minimize energy waste, and reduce operational costs. The best practices for enhancing energy efficiency in pneumatic systems were proper system design, pressure regulation, leak detection and repair, energy-efficient components, and …

Understanding The Limits Of Deep Packet Inspection For Network Traffic Classification, Herman Ramey

Open Access Theses & Dissertations

We present our human network application labeling system that contributes a new level of distinction between the network traffic that should be labeled from the network traffic that should not be labeled. This distinction improves the label accuracy of the training data set produced from the human labeled data and will subsequently improve the performance of supervised machine learning classifiers used for network traffic classification. This system also allows for the human network user to label traffic, with little effort, in a manner consistent with normal network usage, i.e., no need for a contrived experiment. Lastly, we use human supplied …

Prediction Modeling Of Foreign Object Impact Debris On Aircraft Through Digital Engineering, Luis Eduardo Rodriguez

Open Access Theses & Dissertations

The contribution of the research made is derived into two sections. The first topic discusses the prediction modeling of Foreign Object debris (FOd) impact on aircraft structures through the use of digital engineering. The program used in this project is Ansys Explicit Dynamics to evaluate the stress and strain caused by the initial conditions of flight trajectory and impact created from FOd found inside of aircraft structures. The prediction modeling consists of creating a repetition of simulations with different FOds to evaluate the damage created to subsystems of the wing bay such as the fuel system and internal structures. The …

Selective Transfection Of A Transferrin Receptor-Expressing Cell Line With Dna-Lipid Nanoparticles And Synthesis Of Parasite-Derived Glycans As Biomarkers For Leishmaniasis, Irodiel Vinales Lozano

Open Access Theses & Dissertations

Despite notable progress in lipid nanoparticle (LNP)-mediated gene delivery, achieving selective transfection of specific cell types, such as cancer cells, remains a significant hurdle, hindering the advancement of innovative gene therapies. In this study, we engineered an LNP formulation encapsulating plasmid DNA (pDNA) encoding the monomeric Green Lantern (mGL) fluorescent reporter protein. The DT7 peptide ligand targeting human transferrin receptor 1 (hTfR1) was also conjugated to the LNP surface for targeted delivery to hTfR1-expressing cells. Optimization of LNP composition yielded favorable particle diameter, ζ-potential, yield, and pDNA encapsulation efficiency. Evaluation of transfection selectivity using a panel of two engineered cell …

Adipose Stem Cell Response To Borophosphate Bioactive Glass, Nada A. Abokefa, Bradley A. Bromet, Rebekah L. Blatt, Makenna S. Pickett, Richard K. Brow, Julie A. Semon

Materials Science and Engineering Faculty Research & Creative Works

Silicate and Borate Bioactive Glasses Have Been Reported to Create Alkaline Conditions by Rapidly Releasing Ions When Reacting in Aqueous Solution. at Certain Levels, This Alkaline Solution Can Negatively Affect Cell Viability. Adding Phosphate Ions to the Glass Composition Can Control the Degradation Rate of Bioactive Glasses and Create a Neutral PH Environment. This Study Evaluated a Series of Boro phosphate Bioactive Glasses (BPBGs) with Nominal Molar Compositions 16Na₂O_-24CaO-XB₂O₃-(60-X) P₂O₅, Where X = 0, 40, or 60. the Phosphate (X0) Glass (PBG) Produced an Acidic Solution When Dissolved …

Reducing Carbon Emissions With Returned Concrete, John M. Maxwell Jr.

Construction Management

The concrete industry is one of the most energy-intensive sectors of construction. Specifically, the cement production aspect is the most energy intensive, and produces the most carbon emissions. Concrete, a material ubiquitous with nearly every facet of construction; certain types of structures are composed of nearly all concrete. Production of cement is one of the biggest contributors to emissions within the industry. There have been initiatives to reduce or offset emissions from this process, through things like carbon capture, and the purchase of carbon or emissions credits. The objective of this paper was to investigate a new method of carbon …

Little Free Library Project, Baylor Rembrandt

Construction Management

Little Free Library is a non-profit organization dedicated to promoting reading and literacy through community involvement by providing free book exchanges all over the world. The project was comprised of three phases, including design, construction, and installation. I began by identifying potential homeowners interested in hosting a library so that together we could come up with acceptable designs. This required close collaboration with the homeowners and resulted in unique, personalized designs for each library. Next came the construction phase, during which each library presented with its own challenges: the first library tested me with fundamental construction techniques; the second on …

Atascadero Little League - Snack Shack Window Renovation, Anthony J. Catania

Construction Management

Atascadero Little League is an essential part of the local community. It brings families together and provides youth with a place to develop their social skills, sportsmanship, and discipline all while getting outside and exercising. Little leagues are non-profit organizations, managed and operated by volunteers, who sacrifice personal time to give back to their local community. Paloma Creek Park is where Atascadero Little League hosts most of their games. The snack shack’s service window does not face the baseball field, forcing volunteers to rely on a small window in the side of the structure to view their child’s game. The …

Mems Optical Cavities For Low Power Communication., Jacob Schopp

Electronic Theses and Dissertations

This thesis discusses the use of MEMS (microelectromechanical systems) optical cavities for use in low power communication. MEMS optical cavities are thin air gaps between an actuated MEMS mirror and a fixed glass encapsulation. By moving the MEMS mirror the reflectivity of the MEMS optical cavity can be changed. This change in reflectivity can be used to transmit information passively by modulating reflected light intensity instead of generating new light using a light source. These MEMS optical cavities are demonstrated using optical fibers for illumination delivery and reflected light collection. In addition to being reflected for communication, the illuminating light …

Mechanical Property Simulations Of Ploybenzimidazole Membranes., Blake Alexander Clark

Electronic Theses and Dissertations

This work explores mechanical properties of membranes made of polybenzimidazole utilizing molecular simulations. These simulations researchers to narrow down polybenzimidazole membrane compositions to viable candidates. These simulations are quicker than current purely experimental methods. The increase in throughput would be achieved by eliminating compositions that have unfavorable mechanical properties through preliminary simulation work before moving onto experimental methods. Determining polybenzimidazole membranes’ mechanical properties experimentally would, therefore, allow for researchers to speed up research in areas such as fuel cells and electrolyzers that make use of polybenzimidazole membranes. This study uses Materials Studio and the COMPASS III forcefield to perform these …

Acoustofluidic Delivery Of Biomolecules To Cells: A Novel Approach For Preparing Car-T Cells., Madison C. Colebank

Electronic Theses and Dissertations

The continuous pursuit of effective methods for gene transfection in primary human T cells is crucial for advancing cell-based therapies. Viral vectors, currently used in cell-based therapies, involve a lengthy and costly process. This thesis explores the efficacy of coupling acoustofluidic and sonoporation techniques as an alternative non-viral gene transfection approach with primary T cells. Sonoporation, in conjunction with microbubbles, has been demonstrated to induce cavitation, resulting in the formation of pores in the cell membrane through which molecules can enter. Using flow cytometry, we compared the loading efficiency of primary T cells with that of Jurkat T cells to …

Development, 3d Printing, And Sintering Of Aluminum-Magnesium Alloy Pastes For In-Space Manufacturing Applications, Fatou Ndiaye

Electronic Theses and Dissertations

This study explores the additive manufacturing process of paste printing, sintering, and de-binding for fabricating aluminum-magnesium alloy components. The paste formulation involved combining aluminum powder with varying magnesium concentrations, utilizing acrylic polyol, solvent, and plasticizer to create a homogeneous mixture. Printing parameters were optimized to ensure continuous pressure for improved extrusion. Sintering conditions involved incremental temperature increases with nitrogen flow to remove solvents. Density measurements, tensile tests, and shrinkage calculations were conducted to assess part quality post-sintering. The study revealed significant improvements in part quality with 5 wt.% magnesium incorporation within aluminum, although density and tensile strength fell short of …

An Edge Computing System With Amd Xilinx Fpga Ai Customer Platform For Advanced Driver Assistance System, Tsun Kuang Chi, Tsung Yi Chen, Yu Chen Lin, Ting Lan Lin, Jun Ting Zhang, Cheng Lin Lu, Shih Lun Chen, Kuo Chen Li, Patricia Angela R. Abu

Department of Information Systems & Computer Science Faculty Publications

The convergence of edge computing systems with Field-Programmable Gate Array (FPGA) technology has shown considerable promise in enhancing real-time applications across various domains. This paper presents an innovative edge computing system design specifically tailored for pavement defect detection within the Advanced Driver-Assistance Systems (ADASs) domain. The system seamlessly integrates the AMD Xilinx AI platform into a customized circuit configuration, capitalizing on its capabilities. Utilizing cameras as input sensors to capture road scenes, the system employs a Deep Learning Processing Unit (DPU) to execute the YOLOv3 model, enabling the identification of three distinct types of pavement defects with high accuracy and …

Database And Machine Learning Model For Classifying Autism Spectrum Disorder From Smartphone Based Electroretinography, Rory Harris

Honors Scholar Theses

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder that negatively affects a patient’s cognitive and communication aptitude and, therefore, can severely impact that patient’s quality of life. Because of this, early diagnosis is paramount. In recent studies, electroretinography (ERG), which is a measure of the retina’s electrical response to a brief flash of light into the eye, has shown promise in detecting ASD. Access to these scans can provide early diagnosis, improving well-being. Current ERG devices are very expensive due to their on board processing capabilities. This paper aims to create an ERG device using a smartphone as the main …

Development Of A Model To Predict Maximum Crack Width And Spacing In Reinforced Concrete Beams Under Flexural Stress, Saeed Alghamdi

Theses and Dissertations

Cracking in reinforced concrete structures is unavoidable due to the low tensile strength of concrete. Even though minimizing cracks on exposed concrete surfaces is significantly important from the aesthetics point of view, it is also very important for the durability and overall performance of the structure.

Flexural members must be designed to minimize cracking that may occur during the structure's service life. Even though there has been a lot of experimental work on crack width over the last several decades, a literature review reveals that researchers still can't agree on which variables are most important. Part of the reason for …

Amazon Fba Vs Fbm; A Strategic Approach To Determine Which Method Can Effectively Utilize Project Management Principles To Enhance Your Success As A New Amazon Seller., Tiffany Renee White

Theses and Dissertations

Navigating the complexities of a platform such as Amazon demands a strategic approach guided by project management principles. A comparative analysis of Fulfillment by Amazon (FBA) and Fulfillment by Merchant (FBM) methods were completed by focusing on how project management principles optimize product acquisition, supply chain management, and shipping methods for Amazon sellers. The objectives of this study included the identification of top product acquisition tools, the evaluation of inventory management software, assessing shipping methods, and determining the most effective fulfillment process for Amazon seller success. A mixed-methods approach was applied, involving an Amazon seller survey, literature review, data analysis, …

Investigating Potential Improvements To Mbse Software To Support Dodaf, Jennifer Marie Kimpson

Theses and Dissertations

The integration of models created through model-based systems engineering methods with DoDAF is not a new concept. By creating DoDAF-aligned models, DoD program managers are following DoD guidelines to hopefully achieve more effective communication with stakeholders and improve efficiency of their programs. With the use of MBSE tools to create these models, DoD program managers are able to take further advantage of the benefits of MBSE methods. However, even with the use of MBSE tools, there continue to be issues throughout DoD programs. The literature has shown that a continuous improvement approach regarding the use of MBSE tools with DoDAF …