Engineering Commons^™

Rational Design Of Multifunctional Nanocatalysts For Environmental Remediation And Energy Conversion Technologies, Md Ariful Ahsan

Open Access Theses & Dissertations

The discovery of efficient and sustainable carbon-based nanotechnologies to solve both the scarcity of drinking water and global energy crisis has become a paramount task in the last decades. Owed to the fast population growth and industrialization of the modern society, access to potable water and clean energy technologies is becoming very hard around the globe. Water pollutants have become a serious threat to the environment and ecology because of their toxic nature. Parallelly, the current hydrocarbon-based fuel industries are generating high levels of contamination across the planet, making imperative the development of cleaner energy technologies. In this regard, the …

Addressing Security And Privacy Issues By Analyzing Vulnerabilities In Iot Applications, Francsico Javier Candelario Burgoa

Open Access Theses & Dissertations

The Internet of Things (IoT) environment has been expanding rapidly for the past few years into several areas of our lives, from factories, to stores and even into our own homes. All these new devices in our homes make our day-to-day lives easier and more comfortable with less effort on our part, converting our simple houses into smart homes. This increase in inter-connectivity brings multiple benefits including the improvement in energy efficiency in our homes, however it also brings with it some potential dangers since more points of connection mean more potential vulnerabilities in our grid. These vulnerabilities bring security …

The Network Link Outlier Factor (Nlof) For Localizing Network Faults, Christopher Mendoza

Open Access Theses & Dissertations

This work presents the Network Link Outlier Factor (NLOF), a data analytics pipeline for network fault detection and localization solution that consists of four stages. In the first stage, flow record throughput values are clustered in two sub-stages: using Density-Based Spatial Clustering of Applications with Noise (DBSCAN) and then a novel domain-specific ThroughPut Cluster (TPCluster) technique. In the second stage, Flow Outlier Factor (FOF) scores are computed for each flow. In the third stage, flows are traced onto the network. Finally, in the fourth stage, each link is given a Network Link Outlier Factor (NLOF) score which is the ratio …

Goes-16 Level 2 Land Surface Temperature Product-Filling For Cloud Masked Data, Guadalupe Ortega

Open Access Theses & Dissertations

The GOES-16 satellite ground segment team develops different levels of environmental products and makes them readily available to the public. The level 2 Land Surface Temperature (LST) product aims to provide a remote measurement of the Earth’s surface temperature every hour. LST is of fundamental importance to many aspects of the geosciences, for example, to study the Urban Heat Islands (UHI) effect. The product however, does not provide values for pixels where the satellite imager’s view is obstructed by clouds, as determined by a cloud mask intermediate product. The objective of this thesis is to estimate LST in the cloud …

Predicting Zero Bin In The Semiconductor Manufacturing Industry: Machine Learning Algorithms, Yazmin Montoya

Open Access Theses & Dissertations

The semiconductor industry has faced supply chain manufacturing shortages that ultimately led to a worldwide chip shortage during the COVID-19 pandemic. These chip manufacturers use sophisticated and advanced manufacturing machinery in their fabs to manufacture chips. As experienced during the pandemic, manufacturing unavailability is often due to the lack of critical manufacturing-related spare parts. This thesis evaluates the effectiveness of machine learning algorithms to identify significant factors contributing to manufacturing part outages (i.e., zero-bin) to keep manufacturing equipment running at total capacity within the organization. We propose clustering methods to segment the data and use logistic regression, logistic lasso regression, …

Drying Of Digested Biosolids For Weight Reduction Prior To Disposal, Juan Manuel Canales

Open Access Theses & Dissertations

Disposal of belt filter pressed digested sludge (known as biosolids) to landfills cost El Paso Water about $1.1 million in the past year. With an increasing population, the amount of influent wastewater to El Paso treatment plants will also increase, resulting in increased biosolids generation and biosolids disposal costs. A method for reducing biosolids transportation cost is biosolids drying.The cost that El Paso Water pays for transporting biosolids to a dedicated landfill facility is based on the weight of the biosolids that are carried. Biosolids collected from the belt filter presses is about fifteen percent solids by weight, with water …

Thermodynamic Modeling Of Aqueous Fe-Cu-As-Sb-Bi-H2so4 Solutions And Its Application For Redox Potential Determination In Copper Electrorefining From 25°C To 70°C, Yongteng Dong

Open Access Theses & Dissertations

Impurity elements in copper electrorefining (ER) electrolyte have been becoming a crucial issue on purity of copper cathode. The objective of this doctoral research is to develop a speciation model to understand impurity behavior in aqueous ER solutions.

A thermodynamic model of Fe(II)-Fe(III)-Cu(II)-H2SO4-H2O system is developed and shown to reliably simulate the species distribution in industrial copper electrorefining electrolyte from 25°C to 70°C. The previously developed model of Fe(II)-Fe(III)-H2SO4-H2O system under leaching conditions was first evaluated. It has proved that its applicability can be extended to much higher acid concentration (185 g/L) and high amount of copper (40-50 g/L). Cu(II) …

Supercritical Co2 Recompression Closed Brayton Cycle Analysis, Andres Eduardo Gutierrez Hernandez

Open Access Theses & Dissertations

On this research, the results of an analysis made of a Supercritical Carbon Dioxide (sCO2) Recuperated Closed Brayton Cycle (RCBC) done by performing theorical calculations and comparing it to the results obtained with the use of the software ASPEN Plus will be presented. To demonstrate and determine that this software is a useful tool for modeling the proposed type of cycle, a preliminary comparison was made to verify with previous studies found in literature. A comparison and analysis between the possible working fluids and thermal energy sources was also performed to emphasize the decision of using CO2 as the cycle …

Synthesis And Characterization Of Tin (Sn) Incorporated Ga2o3, Guillermo Nicolas Gutierrez

Open Access Theses & Dissertations

In this work, we report on the synthesis, characterization of tin (Sn) incorporated gallium oxide Ga2O3 compounds, also included in this work is the effect of tin concentration related to the optical and electrochemical properties. The Sn incorporation into Ga2O3 creates a significant reduction in the bandgap and causes a nonlinear optical activity as the concentration varies. Substantial investigation performed to the structure, phase, and morphology of the mixed compounds governed by the stoichiometry equation Ga2−2xSnxO3-ɗ indicates that the Sn incorporation from 0.00 ≤ x ≤ 0.30 has a significant effect on these properties. To synthesize the Ga-Sn-O compounds a …

Rarified Water Vapor Deposition From Icy Lunar Regolith On An Engineered Cold Plate, Nathaniel Ian Jurado

Open Access Theses & Dissertations

This work presents the fundamental ice collection experiments conducted under rarefied flow regime to develop a high-capacity cryogenic heat pipe for ice recollection on the Moon’s surface. Preliminary ice collection experiments are conducted under cryogenic vacuum environment of 1.5 × 10-2 Torr and -60 °C. The characterization of water vapor sublimation rates from icy lunar regolith (JSC-1A) at various heating powers is established by utilizing a cryogenic thermal vacuum chamber (T-VAC). A custom-built engineered cold plate is designed, manufactured and tested at various degrees of subcooling and vapor sublimation rates. A thin film heater is embedded within the cold plate …

Evaluation Of Varying Graphene Oxides Through Their Physicochemical Characterizations On Erythrocytes, Hs27 Cells, Escherichia Coli And Staphylococcus Aureus Bacteria Cell Lines, To Assess Graphene Oxides Cytotoxicity., Miriam Montana

Open Access Theses & Dissertations

Research on the toxicity of Graphene Oxides (GO) has captivated interest in the field of material science, environmental sciences, and medicine for their avail significance in biomedical engineer applications either as integrates, enhancements, or in the making of medical devices. Moreover, there is still a lack of understanding as to what characteristics on GOs causes them to be cytotoxic at a cellular level. In our study we synthesized four different GOs by varying in both the method used for oxidation (Modified Hummer’s method & Improved Marcano-Tour’s method), and the precursor parent graphite, for a standardization approach to aid in the …

Environmental Justice Issues And Sea Level Rise In Frontline Communties Along The Gulf Coast, Karla Michel Lopez

Open Access Theses & Dissertations

Sea level rise poses a great threat to coastal areas and our way of life. As flooding increases in frequency and intensity across the country, vulnerable populations become a target to its impacts. The U.S. dedicates much research to risk communication and climate change adaptation strategies; however, these coastal areas are home to a large percentage of underserved and underrepresented communities that can be challenging to meaningfully engage. The impacts of short-term sea level rise combined with long-term sea level rise will not only cause flooding, erosion, and intrusion of saltwater into freshwater resources but also increased financial consequences, such …

Radio Direction Finding Implementing Music Algorithm With Usrp Node Arrays, Kevin Valdez

Open Access Theses & Dissertations

Direction Finding techniques are widely used across the fields of radar, telecommunications, geolocation systems, sonar, among many others to estimate the reference position of the incoming signal source. For this, the implementation of antenna arrays is essential as it allows the use of more advanced techniques in signal processing called spatial spectrum estimation [1]. This method of estimation is performed based on the antenna or sensor array response to the signal spatial parameters in every direction and estimate the location of the incoming signals. Algorithms have been developed for the purpose of spatial spectrum analysis, the most popular are MUSIC …

Identification And Evaluation Of Critical Transportation Infrastructure Resilience After Hydro-Meteorological Event, Herman Serrato

Open Access Theses & Dissertations

Modern civilization is dependent on essential infrastructure assets that allow society to function in today’s standards. Critical interdependent infrastructure such as transportation, communication, security, and public health are marvels of human innovation and an important aspect of civilization's evolution. Recent world events such as climate change have underlined the necessity to develop strategic plans to enhance the resilience of infrastructure. This study aimed to identify and evaluate the flooding potential of critical transportation infrastructure that will influence traffic flow and impact the economy. The technical workflow is based on observations, predictions, experiments, testing, and analysis to derive a resilience score …

Electron Beam Melted Parameter Development Of Pure Tungsten & Post-Processing Hip And Heat Treatment Of Gamma Titanium Aluminide, Kurtis Isami Watanabe

Open Access Theses & Dissertations

Pure tungsten is a refractory metal and has been gaining interest for the use in nuclear fusion reactors as a plasma facing material. Titanium Aluminide (TiAl) has been growing in popularity as a possibly to phase out Nickel based superalloys due to its high specific strength at elevated temperatures. These two materials suffer from poor machinability due to being brittle at room temperature. Additive manufacturing (AM) is a recently developed manufacturing method that is fundamentally different than formative or subtractive. AM is a layer-by-layer process that has the potential to manufacture metals to a near net shape. Since the AM …

Evaluation Of Changes In Behavior And Use Of Pou Systems In The Paso Del Norte Region, Arahim Alejandro Zuniga Herrera

Open Access Theses & Dissertations

According to the world health organization around 2.2 billion people in the world lack access to proper water resources with around 500,000 people dying yearly due to contaminated water ingestion. Colonias are unorganized settlements found on the border between the United States and Mexico and are characterized by poor infrastructure and lack of resources such as water. In the past years, several campaigns have been made to provide water filtration systems to residents in the Paso del Norte colonias, located in the border area of Chihuahua, West Texas, and Southern New Mexico.In the time between the summers of 2018 and …

Structural Impacts Of Super Heavy Load (Shl) Vehicles On Transportation Infrastructure, Ali Morovatdar

Open Access Theses & Dissertations

Operation of non-conventional Super Heavy Load (SHL) vehicles is an ongoing challenge for transportation stakeholders and the traveling public across the nation. Despite facilitating the movement of heavy, large, and non-divisible loads, passages of such vehicles with complex loading configurations that typically weigh several folds of the permissible weight limits set forth by regulatory agencies have been adversely affecting the structural integrity of pavement facilities. This translates into accelerated damage of pavement structures, which in turn poses safety concerns for users of the transportation facilities. Accurate quantification of such detrimental impacts is the precursor to preserve the existing transportation facilities. …

Fabrication Of Alloy 625 Through Electron Beam Powder Bed Fusion Additive Manufacturing, Characterization And Mechanical Performance, Aldo Rubio Hidalgo

Open Access Theses & Dissertations

Electron Beam Powder Bed Fusion (EB-PBF) is an additive manufacturing process that allows for the fabrication of nearly fully dense Alloy 625 parts. In this study EB-PBF Alloy 625 samples were fabricated in an Arcam A2X, heat-treated, then machined and tensile tested. Preliminary process tests varying focus offset, and speed function were conducted to establish baseline process parameter conditions to fabricate Alloy 625 parts based on surface finish and structural defects. The microstructure observed in EB-PBF Alloy 625 parts along the build direction in the as-built state consists of irregularly sized columnar grains averaging 105 μm in width that have …

Cell Bioprinting: A Novel Approach For Alpha Cell To Beta Cell Transdifferentiation, Atzimba Casas

Open Access Theses & Dissertations

Diabetes is a chronic disease that occurs in the body when the pancreas fails to either produce insulin (TID) or does not effectively use the insulin produced (TIID) and poses further health complications as well as an insurmountable economic impact.[1] Type I diabetes is an autoimmune disease characterized by a deficient amount of insulin production on account of the body’s immune system destroying its own β-cells.[2] Current diabetes treatment methods include the administration of insulin via injections or islet transplantation therapy. However, although both are viable options, they come with limitations that make the managing of this disease difficult. It …

Development Of Metaheuristic Algorithms For The Efficient Allocation Of Power Flow Control Devices, Eduardo Jose Castillo Fatule

Open Access Theses & Dissertations

Modern energy grids have become extremely complex systems, requiring more variable and active flow control. As a remedy to this, Distributed Flexible AC Transmission Systems (D-FACTS) are cost-efficient devices used to mitigate power flow congestion and integrate renewable energies. The objective of this research is then to propose an efficient multiple objective evolutionary algorithm to solve a stochastic model for D-FACTS allocation, which aims to optimize various objectives related to cost, grid health, and environmental impacts. The model was implemented on a modified RTS-96 test system, and the results show that optimally allocating D-FACTS modules using the proposed model can …

Phase Transformation And Strain Hardening Mechanisms In Advanced Engineering Steels, Hangyu Dong

Open Access Theses & Dissertations

Strain hardening and associated deformation mechanisms play a determining role in the performance of metallic materials. The objective of the doctoral research was to explore and fundamentally understand the strain hardening mechanisms in the next generation of advanced engineering steels. Two main work hardening mechanisms, notably, twinning-induced plasticity (TWIP) and transformation-induced plasticity (TRIP)) were identified that governed strength and ductility. In the nanograined austenitic steel with high strength-high ductility combination, processed by the novel phase reversion concept, twinning-induced plasticity (TWIP) was the governing deformation mechanism and contributed to good ductility. In striking contrast, transformation-induced plasticity (TRIP) was the deformation mechanism …

Microstructure And Hardness Comparison Of Inconel 625 Alloy Of Various Additive Manufacturing Processes Following Heat Treatments, Ariel Gamon

Open Access Theses & Dissertations

This research study presents experimental examples of as-built microstructures and associated microindentation hardnesses (HV) for a variety of metal additive manufacturing (AM) methods for Inconel 625 alloy. Cold spray (CS), laser powder bed fusion (L-PBF), wire arc additive manufacturing (WAAM), electron beam directed energy deposition (EB-DED), laser hot wire (LHW), binder jetting (BJT), and laser power directed energy deposition (LP-DED), laser wire directed energy deposition (LW-DED) and electron beam melting (EBM) were among the techniques employed. Microstructures varied from impact-bonded, flattened grains containing microdendrites and dislocations with a microindentation hardness of HV 590 for cold spray to large, equiaxed grains …

Supply Chain Optimization Of A Local Small Business From The Food-Service Industry Using Simulation Models, Aimee Montalvo

Open Access Theses & Dissertations

Various supply chain disruptions can cause revenue losses, low productivity, and damaged reputations. Some examples of such disruptions include increased supply costs, labor shortages, pandemics, natural disasters, or transportation delays. For instance, during the COVID-19 pandemic, several small and medium enterprises (SMEs) suffered greatly from labor shortages, delayed and costly supplies, and decreased demand. In this research, we present a case study of a small local business from the fast-food industry that experienced the loss of employees and delays and analyzed the increased cost of supplies. We created visualization modules with the SMEs supply chain performance measures to see the …

Validation Of Computational Model Of A Piezoelectric Flow Rate Sensor, Eben Roberto Escobedo

Open Access Theses & Dissertations

This study validates a computational simulation of a piezoelectric cantilever beam undergoing different loads by showing a comparison of its results against theoretical calculations. The objective of the computational model is to simulate the behavior of a beam made of a piezoelectric material which can be used as a flow rate sensor due to the ability of the material to convert a mechanical load into an electrical load. After validating the model, different geometries, material properties and loads can be simulated to observe the different behaviors and bring the possibility of selecting the most convenient options according to the needs …

Mechanical Properties And Microstructure Evolution Of Thermally Treated Laser Powder Bed Fusion Alsi10mg, Jorge Merino-Gomez

Open Access Theses & Dissertations

The optimization of mechanical properties with thermal postprocessing treatments was investigated in this study across a wide variety of variants. The relationship between heat treatments and the impacts on the mechanical properties and microstructure of printed materials is a crucial part of additive manufacturing. As a result, the current paper provides a comprehensive overview of postprocess heat treatments for Laser Powder Bed Fusion fabricated AlSi10Mg alloy, including stress relief anneals at 190 and 285 degrees Celsius for 2 hours, hot isostatic pressing at 515 degrees Celsius for 3 hours, hot isostatic pressing + T6 treatment for 6 hours, and final …

Small Satellite Development And Mission Design For Low Earth Orbit And Geostationary Transfer Orbit Missions, Ashiqur Rahman

Open Access Theses & Dissertations

Aerospace Center formerly known as cSETR at UTEP is a NASA funded center of excellence in aerospace and exploration, focusing on strategic capability development in propulsion and robotic lander, lunar surface exploration, and small spacecraft technologies. To support the center’s mission for space exploration and to demonstrate advancements in small satellite technologies, the Aerospace Center at The University of Texas at El Paso is on track to develop and launch several CubeSats in next few years. A CubeSat is a small satellite that has become popular in recent years due to their low cost, low complexity and short development timeline. …

Synthesis, Characterization, And Direct-Ink-Writing Of Syntactic Foams, Andrea Irigoyen

Open Access Theses & Dissertations

This project encompasses three different methods to fabricate syntactic foams using a PDMS matrix i.e., hollow spheres inclusion, pore generator leaching by solvent, and emulsion. The foam formation by using polysiloxane hollow spheres is done in a 3-step process. The first step is to create a core of polystyrene following a dispersion polymerization process. The goal for the size of the pore is to monodisperse and have an average diameter of 5-10 μm, so the polystyrene core must be as well within that range. After that, the cores are coated with a polysiloxane shell by following a polymerization by condensation …

Building Energy Model Simulation Of A Single Building In Comparison To A Broader Building Stock, Paola Michelle Santillano

Open Access Theses & Dissertations

Residential facilities and buildings are the largest consumers of energy in the United States. More than 76% of electricity and more than 40% of all energy consumption comes from providing a comfortable and healthy environment in buildings. Prioritizing building energy technology goals for performance and cost can significantly reduce energy use within the next ten years despite a substantial forecasted population increase. Retrofitting existing buildings and improving future construction has the potential to realize cost savings and environmental benefits over time. A key component to realizing these benefits is regional building energy modeling. One of the challenges to widespread building …

A Integrated Approach Of Deep Learning And Augmented Reality For Pneumonia Detection In Chest X-Ray Images, Jeevarathinam Senthilkumar

Open Access Theses & Dissertations

Pneumonia is a viral or fungal illness that spreads to the lungs of the human body, causing fluid to accumulate in the lungs' air sacs. Millions of people are affected by this disease each year. One of the most common radiological diagnostics for diagnosing and screening this kind of sickness is a chest X-ray. The most commonly available radiological test for diagnosing and screening this kind of illness is a chest X-ray. An inaccurate diagnosis, especially over-diagnosis and under-diagnosis, is a common issue in the medical sector. As another issue, human-assisted diagnosis has limitations like the availability of an expert, …

Downscaling Of Goes-16'S Land Surface Temperature Product Using Epitomes, Roberto Garcia

Open Access Theses & Dissertations

Land surface temperature (LST) is an environmental variable derived from thermal infrared (TIR) imagery. Satellite platforms are a good source of TIR imagery because of their ability to provide widespread and frequent coverage of the Earthâ??s surface. It is common that a single satellite remote sensing platform is able to provide images with good spatial resolution or temporal resolution but not both. LST is an important parameter for studies on the urban heat island (UHI) effect. These studies are limited by the spatial or temporal resolutions of available LST products. This Thesis presents an algorithm to estimate land surface temperature …