Engineering Commons^™

Magnesiothermic Combustion Synthesis Of Nanocrystalline Silicon And Oxidation Kinetics Of Magnesium Particles, Sergio Cordova

Open Access Theses & Dissertations

Magnesium (Mg) is a well-known reduction agent in metallurgy (more specifically, in metallothermy). Recently, magnesiothermic reduction of oxides has been used in self-propagating high-temperature synThesis (SHS) of advanced materials such as ultrahigh-temperature ceramics (UHTC). The magnesiothermic SHS has also been used for the conversion of silica (SiO2) to silicon-based materials for thermoelectric applications. However, since oxidation of Mg releases a lot of heat, the direct use of it as the reduction agent leads to excessively high temperatures and undesirable sintering of the products. We have proposed to use magnesium silicide (Mg2Si) instead of Mg in the SHS of nanostructured silicon. …

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 …

Evaluation Of Electrodialysis Desalination Performance Of Novel And Conventional Ion Exchange Membranes, Ahm Golam Hyder

Open Access Theses & Dissertations

It was revealed from relevant recent literature that the electrodialysis (ED) desalination performance of commercial and laboratory-made ion exchange membranes (IEMs) had been studied previously but not in a systematic way so that the planners, designers, and engineers can evaluate a trade-off in selecting the suitable IEMs and optimum ED experimental conditions for their desired outcomes such as high ion selectivity, high salinity removal, high water recovery, low energy consumption, or low water transport. Furthermore, the existing conventional and laboratory-made IEMs reported previously showed various technical and economical limitations with respect to permeability, permselectivity, ion selectivity, electrical resistance, stability (mechanical, …

Evaluation Of Patient Experience Using Natural Language Processing Algorithms, Sofia Veronica Ortega

Open Access Theses & Dissertations

INTRODUCTION: Healthcare organizations are making extensive efforts to improve the patient experience. Enhancing patient/client experience and outcomes is crucial for patient-centered care and can reveal improvement opportunities. Healthcare settings currently rely on surveys (e.g., HCAHPS) and patient feedback to measure patient experience. Studies have identified that utilizing patient journey mapping can better capture patient experience throughout all stages of the patient's journey and provide quality and process improvement recommendations at specific hotspots. However, these measurement techniques are time-consuming and resource intensive. AIM: This research aims to measure patient experience of breast cancer patients from social media data using natural language …

Sensitivity Analysis Of Transportation Emissions On Near-Road Air Dispersion Using The Epa-Approved Gaussian Air Dispersion Model Aermod, Ivan Mauricio Ramirez

Open Access Theses & Dissertations

Departments of transportation across the United States have presented concerns over making the American Meteorological Society (AMS) and U.S. Environmental Protection Agency (EPA) Regulatory Model (AERMOD) the new regulatory air dispersion model for federally funded transportations projects. Concerns arose from the lack of data presented on its use in transportation projects. AERMOD was developed to present a steady-state air dispersion model used on industrial complexes which present static emission sources unlike the dynamic sources presented by transportation projects. We used multiple analytical and statistical methods to further understand the sensitivity of the model results based on different factors and therefore …

Assessing The Impact Of Health Benefits And Carbon Footprint In Student Parking Decisions At A University Campus, Emiliano Ruiz

Open Access Theses & Dissertations

In the student parking location problem, traditionally, the parking permit cost, the last-mile travel time, and the ease of finding an available parking stall are the only decision criteria driving permit purchases. However, a studentâ??s choice of parking location has associated walking health benefits and sustainability impacts. These impacts are related to the walking distance from the parked vehicle to the final destination on campus, in addition to the location effect on the carbon footprint of a vehicle-trip taken to campus. As such, this Thesis examined a multi-criteria decision approach to a university studentâ??s choice of parking location. This approach …

Harmonizing Asphalt Mix Selection With Pavement Structural Design, Mahdi Saghafi

Open Access Theses & Dissertations

The state-of-the-practice in asphalt concrete (AC) mix design and pavement structural design are based on two divergent concepts. The laboratory tests that are used for mix design, especially under the balanced mix design concept, are pragmatically accelerated surrogate tests developed to ensure the stability or ranking of mixes. Pavement structural design methods, being empirical or mechanistic, ignore these laboratory test results, in favor of other mechanical parameters. As such, the selection of the type of mix to be placed on a project is based on the local experience, and a set of consensus limits, rather than the demand of the …

Non-Invasive In-Vitro Glucose Monitoring Using Optical Sensor And Machine Learning Techniques For Diabetes Applications, Maryamsadat Shokrekhodaei

Open Access Theses & Dissertations

Diabetes is a major public health challenge affecting more than 451 million people. Physiological and experimental factors influence the accuracy of non-invasive glucose monitoring, and these need to be addressed before replacing the finger prick method with a non-invasive glucose measurement technique. Also, the suitable employment of machine learning techniques on experimental data can significantly improve the accuracy of glucose predictions.

This work includes the design, development, testing and data analysis of an optical based sensor for glucose measurements. The feasibility of non-invasive measurement of glucose within aqueous solutions that assimilate the composition of human blood plasma is investigated. The …

Geometric Analysis Leads To Adversarial Teaching Of Cybersecurity, Christian Servin, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

As time goes, our civilization becomes more and more dependent on computers and therefore, more and more vulnerable to cyberattacks. Because of this threat, it is very important to make sure that computer science students -- tomorrow's computer professionals -- are sufficiently skilled in cybersecurity. In this paper, we analyze the need for teaching cybersecurity from the geometric viewpoint. We show that the corresponding geometric analysis leads to adversarial teaching -- an empirically effective but not-well-theoretically-understood approach, when the class is divided into sparring mini-teams that try their best to attack each other and defend from each other. Thus, our …

Impact Of Geomaterial Properties And Roller Parameters On Intelligent Compaction Measurement Values Using Lumped Parameter Modeling, Jesús Castro Pérez

Open Access Theses & Dissertations

Roads consist of layers of geomaterials and asphalt or concrete to provide an optimal service life according to their exposure to traffic and the environment. Each layer that forms a pavement structure requires achieving specific quality and mechanical properties that are often obtained only through a proper compaction process. Traditionally, compacted layers are tested using spot methods, which rely on the assumption that the properties measured from a small sample of material represent an entire section. This limitation has led to quality management techniques that continuously monitor the acceleration records from a sensor installed on the roller's drum. These techniques …

Design, Synthesis, And Optimization Of Additively Manufactured Functional Ceramics And Its Composites, Anabel Renteria Marquez

Open Access Theses & Dissertations

The goal of this research consist in the design, synThesis and optimization of functional piezoelectric ceramics and composites that can be fabricated by Direct Ink Write (DIW) 3D printing technique for the use of sensors and energy storage applications. The synThesis optimization of lead-free ceramics for printing was evaluated by analyzing the impact of raw particle size of BaTiO3. A novel approach to evaluate the effect of bimodal distribution raw particle size of BaTiO3 ceramics is presented and their influence on packing density, piezoelectric coefficient and dielectric relative permittivity. Additionally, multi-material DIW printing was adapted as a novel method to …

High Frequency Electron Spin Resonance Investigations On Quasi-Two-Dimensional Chromium Halide Magnets, Christian Saiz

Open Access Theses & Dissertations

Broadening the knowledge and understanding on the magnetic correlations in van der Waals layered magnets is critical in realizing their potential next-generation applications in devices such as spintronics. In this study, we employ high frequency (ν = 120 GHz, 240 GHz) electron spin resonance (ESR) spectroscopy on plate-like CrX3 (where X = Cl, Br, I) to gain insight into the magnetic interactions as a function of temperature (200 – 4.4 K) and the angle of rotation θ (degrees). We find that the temperature dependence of the ESR linewidth is well described by the Ginzburg-Landau critical model, indicative of antiferromagnetic correlations …

Synthesis And Characterization Of Functiona Materials For 3d Printed Composites, Elizabeth Irene Reza

Open Access Theses & Dissertations

The following body of work encompasses the synThesis, upscaling, additive manufacturing, and characterization of microspheres as functional fillers incorporated into polymer syntactic foams. Synthesizing microspheres permits control over morphology, dispersion of particles, and size while the use of direct write manufacturing allowed for the controllability of filler orientation. Two different syntactic foams were developed from similar methodologies: (1) a silicone syntactic foam (2) epoxy syntactic foam. The silicone epoxy foam showed an increasing in damping and elastic modulus. The epoxy syntactic foams showed an enhanced thermal and electrical properties.

Discrepancy-Based Analysis Of Measurement Sampling Points In Compressive Sensing, Felipe Batista Da Silva

Open Access Theses & Dissertations

Compressive sensing (CS) is a technique in signal processing that under certain conditions allows someone to reconstruct sparse signals from fewer linear measurements. A problem in CS is modeled in terms of an underdetermined linear system, whose associated matrix is previously designed. Then, it is of interest in CS to know what a good sampling defined by the sensing matrix is and how to measure it. In this work, we provided analytical proofs of properties of the metric discrepancy that allow us to propose a fast algorithm for discrepancy calculation. Such metric measures the quality of the sampling measurement points …

Multiscale And Multimaterial 3d Printing: Impact Of Feedstock Properties And Processing Parameters On Printed Parts, Kazi Md Masum Billah

Open Access Theses & Dissertations

Material extrusion additive manufacturing (AM) technology is one of the most commonly used technology to fabricate functional prototypes and end-use application parts with custom design. The evolution of the extrusion technology led this particular AM process to grow in many aspects such as new materials development, new design thinking, fabrication of parts in multiscale length, and manufacturing of monolithic parts with multiple functionalities. The research presented in this Dissertation results in the creation of knowledge in material extrusion AM technology with the length scale of production-grade to large-scale 3D printing machine those were used to enable the fabrication of multimaterial …

Bridge Prioritization And Preservation Along Route 66, Sarah Ballard

Open Access Theses & Dissertations

Eligible bridges around the United States receive federal funding every year for replacement or rehabilitation. The main criterion for allocation of this funding is based on engineering aspects (e.g., life safety, condition, functionality), often leaving the historical value of the bridge at the bottom of the importance level. One of the main historical roads known in America is Route 66, also known as the â??Mother Road.â?? This route was the road to opportunity in the 1930s. Many bridges with historical significance carry the route and represent an integral part of the history of the Mother Road. This research analyzes bridges …

Engineering Cardiac Tissues With Three-Dimensional Bioprinting For Biomedical Applications, Matthew Alonzo

Open Access Theses & Dissertations

The role of a biomedical engineer is to solve unmet health-related needs that face society. For the past couple of decades, heart disease (HD) has remained the leading cause of mortality and morbidity worldwide. The disease is characterized by various pathologies that affect the heart. Indeed, malfunction of one of the bodyâ??s most vital organs is bound to manifest poor health and even death in patients. Despite advances in medicine and technology, heart disease continues to be prevalent and diminishes the quality of life for many around the world. Certainly, there exists a need for developing new tools to better …

Fabrication And Testing Of Advanced Composites For Extreme Environments, Victoria Centeno

Open Access Theses & Dissertations

The following research focuses on the additive manufacturing and characterization of epoxy syntactic foams that utilize hollow carbon microspheres (CMS) and graphene-coated hollow carbon microspheres (GCMS) as fillers. The matrix that is utilized in this study is a thermoset epoxy resin, chosen for its high strength, low shrinkage, excellent adhesion to various substrates, effective electrical properties, chemical and solvent resistance, low cost, and low toxicity.1 CMS and GCMS were used as fillers for the properties they contribute to the overall epoxy syntactic foam, and can be seen in Fig.1.1. CMS consist of outer stiff carbon and inner gas, giving the …

Digital Twin Technology Applications For Transportation Infrastructure - A Survey-Based Study, Hector Cruz

Open Access Theses & Dissertations

In the past couple of decades, various industries have taken advantage of emerging advanced technologies, such as digital twin (DT), to find more effective solutions in their respective areas. In the transportation infrastructure sector, the concept and implementation of DT technologies are slowly gaining traction but lagging behind other major industries. To better understand the limitations, opportunities and challenges for the adoption of DT in this sector, a survey questionnaire was distributed to collect information from industry professionals involved in transportation infrastructure projects. The purpose of this study is to understand how DT technology is being perceived by the industry. …

A Study Of The Frustrated Honeycomb Battery Material Na2ni2teo6, Nathan Christopher Episcopo

Open Access Theses & Dissertations

The P2-type layered hexagonal compound Na2Ni2TeO6 with Ni2+ on a honeycomb lattice was synthesized by the standard solid-state route. Structural characterization chemical phase purity was confirmed by Rietveld refinement of laboratory and synchrotron data. The crystal structure refines well in the P63/mcm space group. Single crystal growth trials using the self-flux-melt method were conducted with limited success. The magnetic transition temperature pertaining to Ni2+ lattice was confirmed by analysis of specific heat capacity to be . The magnetic susceptibility remains largely unchanged in magnetic field of and external pressure of . There is an almost linear response in isothermal magnetization …

Application Of Machine Learning In Flood Depth Prediction, Armando Esquivel

Open Access Theses & Dissertations

Machine learning technologies have helped provide answers for problems with a high degree of complexity. Machine learning has been utilized by various disciplines within the Civil Engineering profession and has proven to be efficient in solving complex problems. Although machine learning is being used in the Civil Engineering profession, a formal framework on developing and integrating machine learning has not been developed for flood depth prediction. The proposed word uses machine learning to predict the depth of flood at Houston, TX, due to a 100-year 24-hour storm. The proposed work can be used to collect, store and analyze data to …

New Generation Of Performance-Engineered Asphalt Mixtures Based On Balanced Mix Design Concept, Victor Manuel Garcia

Open Access Theses & Dissertations

Asphalt mixtures must ideally exhibit long-lasting durability and stability to perform wellin the field. However, improving the stability and durability of asphalt mixtures has become a major concern. Given that available design approaches rely mainly on stringent volumetric criteria for asphalt mixtures, design approaches and specifications that incorporate performance tests are needed to follow a performance-engineered mix design (PEMD) process, especially with the introduction of the balanced mix design (BMD) concept

This Dissertation study presents a comprehensive investigation of a feasible designapproach that can be implemented to develop PEMD specifications and produce BMD mixtures. An experimental evaluation of different mix …

Evaluation Of The Cytotoxyc Effects Of Lmdf5-7 On A Human T-Cell Leukemia Cell Line, Andrea F. Ibarra Chacon

Open Access Theses & Dissertations

According to World Health Organization (WHO), cancer is the second leading cause of death worldwide, with 9.6 million deaths in 2018 . In the United States, an estimated 434,982 people were living with cancer during 2017 . Leukemia is the most common blood cancer in children from birth to 14 years old . In particular, Hispanic children in the United States experience a higher incidence rate of leukemia . Therefore, the discovery of novel cancer therapies is necessary to help those affected survive the disease. A new compound, LMDF5-7 was investigated and found to have anticancer properties that can help …

Implementation Of Hma Design Tool To Develop Balanced Mix Design Based On Gradation Parameters, Prathmesh Deepak Jichkar

Open Access Theses & Dissertations

With the rapid paradigm shift of pavement design methodology from an empirical-based approach toward a more mechanistic-based approach, the existing mix design processes also need a radical shift from the conventional volumetric-based methods to performance-based methods. The use of a volumetric-based design methodology has become more challenging due to the increasing use of recycled materials, modified binders, warm mix asphalt additives, compaction aids, and rejuvenators. A shift toward the more fundamentally sound â??balanced mix designâ?? (BMD) concept is envisaged to produce asphalt concrete mixtures with acceptable performance in terms of durability and stability. Aggregate gradation plays a crucial role in …

Development And Testing Of Nanostructured Materials For Extreme Environment Applications, Nanthakishore Makeswaran

Open Access Theses & Dissertations

Nanostructured materials have many potential applications in the fields of power generation and transportation technologies, particularly in the areas of gas sensing technology, industrial gas turbines and protective coatings. In the former case β-Ga2O3 represents a promising candidate due to its high degree of stability and functionality for oxygen sensing at higher temperatures (>700oC). In the latter case, the application of Y-Si-Fe compounds acting as environmental barrier coatings for gas turbine and aerospace engine applications to protect from corrosion effects has been demonstrated in recent years. In both cases, however, there is room for improvement whether it is in …

Microstructural Evolution And Mechanical Properties Of L-Pbf Aerospace Alloys: Hydride- Dehydride Ti-6al-4v And Experimentally Heat-Treated Inconel 718, Jaime Varela

Open Access Theses & Dissertations

Experimental HIP and heat treatment cycles were applied to Laser Powder Bed Fusion fabricated Inconel 718 parts. Recent advances allow for rapid cooling in the HIPing chamber allowing one unit to perform HIP along with other heat treatment cycles such as solution annealing and ageing. Different cycles yield various effects on the porosity reduction as well as the growth of grain in the microstructure, consequently presented different mechanical properties. Specimens were therefore analyzed for density, microstructure, and tensile properties.

In addition, the mechanical and microstructural analysis of HDH Ti-6Al-4V was performed. The high cost of GA Ti64 material is a …

Effect Of Dopants On The Properties And Performance Of Gallium Oxide: Bulk Ceramics And Nanomaterials, Vishal Bhimrao Zade

Open Access Theses & Dissertations

A comprehensive investigation performed in order to understand the fundamental aspects of transition metal (TM) incorporation into Ga2O3, a wide band gap semiconductor with a huge potential for application in electronics, optics, micromechanics and optoelectronics. An approach is presented to tailor the structural, optical, electrical, mechanical properties of Ga2O3 ceramics and thin films. The tungsten (W) mixed Ga2O3 with variable W at% (Ga2-2xWxO3 ; 0.00 ≤ x ≤ 0.30) were synthesized by the high temperature solid state route involving a 2-step calcination process. The solubility limits and phase stability of the compounds are established. While solubility and phase stability occur …

Post Processing Of Electron Beam Melted Ti-6al-4v And Binder Jetted 17-4 Stainless Steel, Ahmad Omar Abu-Issa

Open Access Theses & Dissertations

An extensive assortment of HIP parameters have been altered on EBM fabricated Ti-6Al-4V and have shown that cooling rates of 103 oC/min from temperatures above and below the beta transus produced acicular alpha-prime martensite characteristic elongations < 10 %. Optimum yield strength (0.9 GPa), UTS (1.0 GPa) and elongation (~14 %) were achieved for slow cooling (at 102 oC/min) from 850 oC HIP which produced a dense, Widmanstatten alpha structure within the retained, as-fabricated columnar grains by alpha-prime decomposition. These results suggest that manipulation of AM process parameters to produce a small-grain, equiaxed microstructure, HIPed below the beta transus and slow cooled, will have a wide range of superior, isotropic mechanical properties corresponding to a Widmanstatten alpha microstructure within the equiaxed grains. Also, Binder Jetting printing parameters for differing PSD's of low-cost water-atomized 17-4 Stainless Steel were optimized in order to produce high dense parts. Densities ranging from 94-97.5% were achieved, and issues of inhomogeneous porosity were addressed using a fumed silica flow additive.

Adaptive Lean Manufacturing Implementation For Organizations With Rapid Leadership Turnover, Brett Babcock

Open Access Theses & Dissertations

Lean Six Sigma seeks to optimize workplace efficiency and is now world renowned as the standard for how to maximize profits, perfect quality control, and emphasize workplace safety. Almost every large scale engineering company has in some shape or form a Lean Six Sigma aimed concept of operations to the point that a subset of the Lean Six Sigma Institute is focused towards compiling packages to assist those companies that have not implemented it to make the transition. These packages while efficient, operate with the understanding that the ideologies they deploy will be implemented from the top down and that …

Geotechnical Aspects Of Martian Regolith Simulant Jsc Mars-1, Jesus Baca

Open Access Theses & Dissertations

The primary objective of this research was to mechanistically characterize the physical and mechanical properties of the JSC Mars-1 regolith simulant to better understand its physical, mechanical, and physio-chemical properties. JSC Mars-1 is a regolith simulant developed by the National Aeronautics and Space Administration (NASA) at the Johnson Space Center (JSC) based on the data collected by instruments on the Viking and the Pathfinder landers. A comprehensive experiment matrix was devised to simulate the extraterrestrial compaction characteristics of unbound simulants in the laboratory. The resilient properties, strength parameters, and deformation potential were of primary interest in this effort. In addition, …