Engineering Commons^™

Structural And Optical Investigations Of Rbxcs1-Xh2po4, Alex D. Price

Open Access Theses & Dissertations

Proton conductor solid acid electrolytes RbxCs1-xH2PO4 (0≤x≤1) have been investigated using second harmonic generation and powder x-ray diffraction. Second harmonic generation is an optical technique which can be used to study the structural properties of materials. Microscopes of this nature have the ability to image objects with a variable penetration depth in a non-destructive manner, allowing for great potential to be used for in situ observations of the electrolyte’s structure when in a fuel cell under operating conditions.

X-ray powder diffraction was carried out on the series of samples and found for values of 0≤x≤0.5 the structure of the material …

Hybrid 3d Printing Demonstrated By Arbitrary 3d Meandering Transmission Lines, Ubaldo Robles

Open Access Theses & Dissertations

This Dissertation focuses on the automation of multi-material direct write three-dimensional (3D) manufacturing of arbitrary metal-dielectric structures. The technology was demonstrated by manufacturing 3D meandering interconnects and transmission lines (TLs). Manufacturing 3D functional electronics with multiple materials required pushing the current state of 3D printing (3DP) technology to utilize simultaneous multi-material processes combined with sophisticated slicing and bonding under one process. Multi material 3DP is known as hybrid 3DP. This research pioneered the process for producing meandering transmission lines, starting with design and manufacturing, using hybrid 3DP through micro-dispensing and fuse deposition modeling. The research starts by 3DP magnetic and …

Experimental Laser Powder Bed Fusion System For Difficult To Process Metallic Materials, Syed Zia Uddin

Open Access Theses & Dissertations

The focus of this research was twofold, such as development of defect free fabrication parameters for laser powder bed fusion (LPBF) processing of crack prone or difficult to process metallic materials, and study of the temperature dependence of emissivity for some commonly used metal alloy powders in LPBF process. The later objective extends to the implementation of multiwavelength (MW) pyrometer technology for in situ true surface temperature measurement in LPBF process. LPBF is an additive manufacturing (AM) process capable of layer-by-layer manufacturing by successive laser melting of each layer according to CAD data. AM manufacturing has the inherent advantages of …

Technical Project Management: Union Of Systems Engineering Processes With Project Management Processes, Deyaaldeen M. Abusal

Open Access Theses & Dissertations

Today, most projects in technical fields utilize project management to complete projects as planned, and some of the projects utilize system engineering to cover the project in both technically and commercially. This Thesis investigates the relationship between Project Management (PM) and Systems Engineering (SE) to determine if a suitably professional level of management and level of quality can be achieved. When studying PM and SE separately and make a comparison between both, there is much overlap between these two mature fields. The project could be planned and completed solely by either process. This study combines both fields of Project Management …

Testing Of A 1n Af-M315e Thruster, Daniela Ivette Aguilar

Open Access Theses & Dissertations

The Center for Space Exploration and Technology Research (cSETR) at the University of Texas at El Paso (UTEP) is currently pursuing various space propulsion and small satellite projects. One of these projects is called Orbital Factory X (OFX), which mission is to design a 2U Cube-Satellite (Cube Sat) with 4 green mono-propellant thrusters along with multiple micro-cathode arc thrusters. A CubeSat is a small-scale version of a satellite that is usually placed in orbit for near earth missions. However, they have a relative short life and limited maneuverability due to their limited source of power and restricted payload. Now, technologies …

Utilization Of Digital Image Correlation Technique In Asphalt Testing, Alejandra Escajeda

Open Access Theses & Dissertations

Over 90% of the roads in the United States are paved with hot mix asphalt (HMA). These asphalt pavements include many mix types, such as permeable friction course (PFC), stone mastic asphalt (SMA) and conventional dense graded mixes. The performance of the HMA is an important factor in pavement design programs used by many departments of transportation. The type of HMA selected not only influences the performance of the pavement structure, but also the pavement's life cycle cost. The performance life of an HMA mix is to be studied further with experimental data in order to contribute and expand on …

Onshore-Offshore Velocity Models North Of The Mendocino Triple Junction In Northern California, Alan Jacquez

Open Access Theses & Dissertations

The Mendocino Triple Junction (MTJ) marks the boundary where the Gorda plate, North American Plate, and Pacific Plate meet, separating the Cascadia subduction zone to the North from transform tectonics of the San Andreas plate boundary. This actively deforming region experiences high seismic activity and young geological features. Here we examine offshore and onshore seismic wide-angle reflection and refraction data north of the MTJ crossing the Cascadia subduction zone from offshore northern California to the Western edge of the Sierra Nevada. We image subsurface structures in this region by creating P-wave velocity models using datasets collected in 1993 to 1994 …

Geospatial Relationship Of Intelligent Compaction Measurement Values With In-Situ Testing For Quality Assessment Of Geomaterials, Luis Alberto Lemus

Open Access Theses & Dissertations

The implementation of Intelligent Compaction (IC) in the construction of transportation infrastructure as a tool for quality control of compacted geomaterials has attracted the attention of a number of highway agencies. Compaction quality has been conventionally assessed using density, and to a less extent, modulus-based spot measurements at selected locations along the roadway section. While spot measurements do not provide a thorough rendition of the level of compaction of the roadway, IC technology is effective in meeting full coverage requirements. IC roller measurements are accelerometer-based measurements recording machine-ground interaction assumed to be indicative of the stiffness of the compacted geomaterial. …

Implementing Large Eddy Simulation To Numerical Simulation Of Optical Wave Propagation, Diego Alberto Lozano Jimenez

Open Access Theses & Dissertations

In this study, we want to simulate long-range laser propagation in atmospheric turbulence. The numerical simulations are carried out to study the impact of strong atmospheric turbulence in spatial, temporal, and related spectral domains. The first section of this study will be concerned with modeling this numerical simulation in Kolmogorov and non-Kolmogorov spectrum. To validate our numerical simulation, we will compare the statistical parameter to theoretical approximation in both Kolmogorov and non-Kolmogorov spectrums. Once the code is validated, we want to integrate Large Eddy Simulation (LES) turbulence modeling. LES simulations allowa us to study strong fluid turbulence and can predict …

Titanium Incorporated Gallium Oxide (Ga-Ti-O): Structure Property Relationship And Performance Evaluation For Extreme Environment Applications, Sandeep Manandhar

Open Access Theses & Dissertations

The existing power generation systems, which utilize fossil fuels, are in dire need of efficient, reliable chemical sensors that can operate safely at higher temperatures. These sensors control the combustion environment and the emissions during combustion. Several sensing materials such as SnO2, ZnO, TiO2, WO3, and Ga2O3 exhibit high sensitivity to certain type of chemical molecules and in a certain range of temperatures. Among these candidate materials, β-Ga2O3 is stable at very high temperatures and has shown functionality for oxygen sensing at higher temperatures (>700°C). However, the response time and sensitivity must be significantly improved in order to derive …

Evaluation Of Recycled Gypsum Application Dosages To Enhance The Water Infiltration Rate At Water Retention Ponds, Jorge Luis Navarrete

Open Access Theses & Dissertations

The retention ponds play central role for efficient collection, removal, and drainage of rainfall runoff from surrounding streets to minimize flooding and damage. However, low percolating retention ponds may result in an extended ponding of water, abundance bacteria accumulations, mosquito breeding, environmental hazards, among others. The presence of clayey soils and soil sodicity reduces infiltration rates of retention ponds. To enhance the infiltration rate of ponds, it is proposed to use recycled gypsum (RG), as a soil amendment in retention ponds consisting of clayey soils to enhance low infiltration rates.

To evaluate the influence of RG in clayey soils as …

Design Of Robotic Tram Unit For Field Data Collection, Quetzalcoatl Mendoza Rosas

Open Access Theses & Dissertations

Satellite remote sensing is the most applied method for detection and measurement of electromagnetic energy and its interaction with Earth surface. the analysis of the data acquired can provide important information with uses in areas as like weather forecasting, military intelligence and environmental and resources location. Due to the great distance from where the samples are taken and even with the most sophisticated sensor it is impossible to have an exactly replica of the Earth surface. As a result, scientist analyze imagery where a single pixel can be the representation of a 30 by 30 meters area of land. This …

Magnetotelluric Analysis Of Central Kenya Kenyan Rift Volcanoes For Geothermal Development, Anna Wairimu Mwangi

Open Access Theses & Dissertations

Abstract

High temperature geothermal resources are vast along rift margins because of emplacement of magma in shallow crust. This is the case along the Kenyan Rift valley also known as the Gregory Rift. It is the Eastern arm of the East African rift and a chain of volcanoes along the rift graben characterizes it. We use (MT) magnetotelluric method to image beneath the peralkaline province of the Kenya Rift i.e. Olkaria, Eburru, Badlands, and Longonot volcanoes. The resistivity structure shows active geothermal activity happening at the upper 3km from the subsurface as evidenced by low resistivity cap rock comprised of …

Streamlining Alloy Design And Thermo-Mechanical Processing Parameters For High Strength Line Pipe Steels And Hot Rolled Microalloyed Steels: Process - Structure - Property Paradigm, Venkata Vignesh Natarajan

Open Access Theses & Dissertations

The process parameters related to thermo-mechanical controlled processing (TMCP) of steels play a vital role in affecting the ultimate mechanical properties. We illustrate here the impact of coiling temperature, the impact of finish cooling temperature on interrupted cooling and compare with continuous cooling, and the impact of carbon and niobium on the microstructure and precipitation behavior and corresponding changes in mechanical properties, in an ultrahigh strength titanium-niobium microalloyed steel. The microstructural advancement was contemplated via transmission electron microscopy and electron backscattered diffraction (EBSD). The goal was to underscore the impact of coiling temperature on the nature and distribution of microstructural …

Development Of A Desktop Material Extrusion 3d Printer With Wire Embedding Capabilities, Jose Francisco Motta

Open Access Theses & Dissertations

Printed circuit boards (PCB) have been widely used as a permanent solution for generating complex circuitries to power electronic devices. Over the years, PCB boards have proved to be reliable when powering electronic devices. However, when fabricating a printed circuit board, one must outsource to fabricate the boards when in prototype phase. Therefore, the risk of intellectual property theft and long lead time is an issue. The objective of this Thesis is to develop a hybrid multi-tool desktop material extrusion 3D printer that allows for easy integration (modularity) of tools to generate multi-functional 3D printed components.

The addition of an …

Formulation Of Nanoparticle Systems For Drug Delivery Application In Biomedical Sciences, Victor Alfredo Rodriguez

Open Access Theses & Dissertations

Antibiotic-resistant strains of bacteria may result in serious infections which are difficult to treat. In addition, the poor antibiotic pipeline has also contributed to the crisis. Recently, the complex of furosemide and silver (Ag-FSE) has been reported as a potential antibacterial agent. However, its poor aqueous solubility is limiting its activity as an effective antibacterial agent. The purpose of this study was to encapsulate Ag-FSE into chitosan nanoparticles (CSNPs) and evaluate antibacterial efficacy. Ag-FSE CSNPs were prepared using ionic gelation technique. The particle size, polydispersity index and zeta potential of Ag-FSE CSNPs were determined using dynamic light scattering (DLS) technique. …

Extraction Of Fiber Morphology From Sem Images For Quality Control Of Fiber Reinforced Composites Manufacturing, Md Fashiar Rahman

Open Access Theses & Dissertations

The morphology of fibers (e.g. spatial uniformity, orientation, and length) plays a decisive role in determining the material properties or fabrication quality of fiber-reinforced nanocomposites. Hence, determining the morphology becomes a very critical issue in the field of nanocomposite quality control. The conventional way of quality inspection is to take the scanning electron microscopic (SEM) images of the cross-section of composite material and do the visual checking of these SEM images to evaluate the nanofiber alignment and length distribution. But this type of inspection is often subjective, inaccurate and time consuming. Moreover, the extremely small size of nanofibers makes the …

Evaluation Of Commercial Pervaporation Membranes For Desalination Of Saline And Brackish Waters, Andres F. Sanchez

Open Access Theses & Dissertations

Pervaporation is a solution separation method that occurs by vapor transport through a selective membrane. As the need to provide drinking water to the growing population increases, pervaporation has potential merit as an alternative desalination technology, especially for water with very high salinity.

To our knowledge, there are no commercially available pervaporation membranes made specifically for desalination applications. Thus, the membranes PERVAP 4100 and PERVAP 4101 manufactured by DeltaMemAG were tested to evaluate their performance in desalination. Because the driving force in pervaporation is the difference in vapor pressure between the feed side and the permeate side of the membrane, …

Evaluation Of Large Area Additively Manufactured Fiber Reinforced Acrylonitrile Butadiene Styrene (Abs), Kevin Schnittker

Open Access Theses & Dissertations

To enable the advancement of large-scale additive manufacturing processes, it is necessary to establish and standardize methodologies to characterize the mechanical properties of printed test coupons. Due to the large size of the print beads, conventional test standards are inadequate. The focus of this study was to determine the feasibility of using Digital image correlation (DIC) technology as a key enabler for robust data collection of strain measurements of large 3D printed parts. To incorporate the DIC measurements, a novel method was developed to prepare large 20 wt.% glass filled ABS test coupons for adequate contrast. Through this technique, Poisson's …

Assessing Performance Of Detectors Of High Frequency Oscillations In Eeg Signals, Deeksha Seetharama Bhat

Open Access Theses & Dissertations

Attempts to perform epileptic seizure prediction have been made for decades, but there is no solution yet that is generally effective, though some progress in this area has been reported. Interictal epileptic spikes were considered as the only biomarkers of seizure-generating brain tissue until the recent discovery of high-frequency oscillations (HFOs) in electroencephalographic (EEG) signals, with frequency contents in the range from 80 Hz to 800 Hz. HFOs are now considered as biomarkers of epileptogenic tissue and the seizure onset zone. However, there are challenges in the definition and detection of HFO events which complicate this perspective. In studies about …

Impact Of Highway Work Zones On Traffic Crashes: A Case Study In Michigan, Qadri Hafez Shaheen

Master's Theses and Doctoral Dissertations

Infrastructure in the US is severely aged and outdated. This presents a seemingly paradoxical problem in the field of construction management: In order to fix and make roads and highways more safe, construction zones must become inherently less safe in the process. There is a high cost to taxpayers and drivers, as work zones experience a significant amount of crashes and fatalities each year. To mitigate some of the factors that contribute to these crashes, this paper attempts to deliver guidelines on how to update relevant crash data, identify relevant factors, and create recommendations accordingly. The research focused particularly on …

Limit Analysis On Seismic Stability Of Anisotropic And Nonhomogeneous Slopes With Anti-Slide Piles, Wei Bing Gong, Jing Pei Li, Lin Li

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

This study employs the limit analysis method to evaluate the seismic stability of anisotropic and nonhomogeneous slopes stabilized with anti-slide piles. The pseudo-static approach is used to simplify the earthquake load. The yield seismic acceleration factor is obtained from the optimization procedure and the results are verified with the published data. Then, the seismically unstable slope is reinforced with anti-slide piles, and the seismic stability of the reinforced slope is explored. The results show that the anisotropy and Non homogeneity of soils have significant effects on the stabilizing force required from the anti-slide piles and the optimal location of the …

Probing The Wave Nature Of Light-Matter Interaction, D. E. Boone, C. H. Jackson, A. T. Swecker, J. S. Hergenrather, K. S. Wenger, O. Kokhan, Balša Terzić, I. Melnikov, I. N. Ivanov, E. C. Stevens, G. Scarel

Physics Faculty Publications

The wave-particle duality of light is a controversial topic in modern physics. In this context, this work highlights the ability of the wave-nature of light on its own to account for the conservation of energy in light-matter interaction. Two simple fundamental properties of light as wave are involved: its period and its power P. The power P depends only on the amplitude of the wave’s electric and magnetic fields (Poynting’s vector), and can easily be measured with a power sensor for visible and infrared lasers. The advantage of such a wave-based approach is that it unveils unexpected effects of light’s …

Cryogenic Probe Station At Old Dominion University Center For Accelerator Science, Junki Makita, Jean R. Delayen, Alex Gurevich, Gianluigi Ciovati

Physics Faculty Publications

With a growing effort in research and development of an alternative material to bulk Nb for a superconducting radiofrequency (SRF) cavity, it is important to have a cost effective method to benchmark new materials of choice. At Old Dominion University's Center for Accelerator Science, a cryogenic probe station (CPS) will be used to measure the response of superconductor samples under RF fields. The setup consists of a closed-cycle refrigerator for cooling a sample wafer to a cryogenic temperature, a superconducting magnet providing a field parallel to the sample, and DC probes in addition to RF probes. The RF probes will …

A Simple Model For Elastic-Plastic Contact Of Granular Geomaterials, Jian Wang, Qimin Li, Changwei Yang, Yidan Huang, Caizhi Zhou

Materials Science and Engineering Faculty Research & Creative Works

We propose a simple elastic-plastic contact model by considering the interaction of two spheres in the normal direction, for use in discrete element method (DEM) simulations of geomaterials. This model has been developed by using the finite element method (FEM) and nonlinear fitting methods, in the form of power-law relation of the dimensionless normal force and displacement. Only four parameters are needed for each loading-unloading contact process between two spheres, which are relevant to material properties evaluated by FEM simulations. Within the given range of material properties, those four parameters can be quickly accessed by interpolating the data appended or …

Femtosecond Laser-Matter Interactions In Ternary Zinc Phosphate Glasses, J. Hernandez-Rueda, N. W. Troy, P. Freudenberger, Richard K. Brow, D. M. Krol

Materials Science and Engineering Faculty Research & Creative Works

We investigate the interaction of ultrashort laser pulses with ternary zinc phosphate glasses. We explore the viability of ten different glass compositions with different levels of alumina to inscribe optical waveguides via the fs-laser direct writing technique, finding that only samples with [O]/[P] ratios of 3.25 are suitable candidates. We also test a zinc magnesium phosphate glass to fabricate waveguide Bragg gratings in order to generate filters and mirrors with specific spectral properties. Confocal Raman spectroscopy inspection shows that laser-damaged material exhibits a relative intensity decrease and a subtle blue-shift on the 1209 cm-1 Raman peak, which implies a relative …

Effect Of Thickness On The Structure And Corrosion Performance Of Sputtered Ce-Al-O Coatings On Al 2024-T3 Alloy Substrates, Yuanyuan Liu, Jiamu Huang, Lilu Qin, James B. Claypool, Matthew J. O'Keefe, Yiming Jiang

Materials Science and Engineering Faculty Research & Creative Works

Ce-Al-O coatings with thicknesses between ca. 136 nm and 1094 nm were deposited on Al 2024-T3 alloy substrates using magnetron co-sputtering of independent Al and CeO2 targets. The Ce-Al-O coatings with thicknesses from ca. 136 nm to 490 nm were compact, dense, and did not have distinct X-ray diffraction peaks. The ca. 1094 nm thick Ce-Al-O coating exhibited a columnar-textured outer layer ∼700 nm thick and a dense, ∼390 nm thick inner layer. X-ray photoelectron spectroscopy analysis revealed that the Ce-Al-O coatings contained Ce (III) species, and that the Al/Ce atomic ratio decreased with increasing coating thickness. Electrochemical corrosion data …

Noise Induced Hearing Loss Accountability On Jobsites Within The Construction Industry, Joseph O. Lamphere

Construction Management

Noise induced hearing loss is a major issue on jobsites within the construction industry. Every day workers are exposed to hazardous levels of noise, but they are not being properly managed to mitigate this issue. Workers have misconceptions about the topic, but more surprisingly are sometimes indifferent to the effects; believing hearing loss is inevitable, or it can be cured with a hearing aide. Construction has inherent dangers that workers have to deal with every day. Hearing loss might not be on the top of their lists, but the effects are permanent, and they cannot be cured with a hearing …

Multi-Hazard Vulnerability Assessment Of Monopile Foundation Offshore Wind Turbines, Jharna Pokhrel

Electronic Theses and Dissertations

Offshore Wind Turbines (OWTs) have increased in popularity because of numerous technological advancements in the sector of renewable energy. With such an increase in the number of installments, there is a need for multi-hazard vulnerability assessment of the OWT at a given site. Because of hurricane and tsunami loads pertaining to the offshore site, structural failure analysis with respect to wind and wave loads at the critical section of the OWT is required. The existing simulation methods for the failure assessment are computationally expensive and require many simulations to estimate the multi-hazard behavior. The goal of this thesis was to …

Set-Theoretic Model Reference Adaptive Control Of A Generic Transport Model, Ehsan Arabi, Tansel Yucelen, Nhan T. Nguyen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper illustrates an application of a recently developed set-theoretic model reference adaptive control architecture on a generic transport model developed by NASA. The set- theoretic model reference adaptive control allows the system error bound between the state of an uncertain dynamical system and the state of a given reference model to be less than a-priori, user-defined worst-case performance bound. Thus, it has the capability to enforce strict performance guarantees to the adaptively controlled uncertain dynamical systems. specifically, after designing set-theoretic adaptive controllers for both longitudinal and lateral-directional dynamics here, the efficacy of this architecture is illustrated on the NASA …