Engineering Commons^™

Towards Multiple Model Approach To Bridge Deterioration, Jin A. Collins

Open Access Theses & Dissertations

The Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA) marked the start of a new era in transportation in the United States. ISTEA required transportation agencies to take a proactive approach to planning and management of their assets. This included requirements for managing pavement, bridges, safety, congestion, public transportation, and intermodal systems. For horizontal transportation assets (i.e., bridges and pavement), deterioration modeling is an essential tool (Yanev and Chen 1993). Since ISTEA, Bridge Management Systems (BMS) have been utilized to inform decision-making regarding bridge projects such as maintenance, rehabilitation, and replacement (MR&R) under financial limitations (Agrawal, Kawaguchi, and Chen 2010). …

Energy Efficiency And Fatigue Failure On Gears And Bearings For Processing Rebar Steel, Jesus Gabriel Garcia

Open Access Theses & Dissertations

Steel industry is a major emitter of air pollutants, a leading industrial consumer of water, a minor source of contaminated liquids, a massive producer of solid waste, and a significant source of CO2. The objective on this thesis work is to minimize the greenhouse gas emissions when processing steel. Gears and bearings were evaluated based on their performance when exposed to cyclic stresses. The importance for having a proper set up on rolling mills to increase efficiency for processing rebar steel has been detailed on paper. In contrast, mechanical vibration has been measured on gears and bearings to determine efficiency …

Development And Characterization Of Polyethylene Terephthalate (Pet)-Cotton Natural Fiber-Reinforced Composites From Waste Materials, Israel Alejandro Carrete

Open Access Theses & Dissertations

Unprecedented levels of production and consumption have caused a rapid exhaustion of the Earth's virgin resources, which is coupled with a fast accumulation of contaminants in the form of solid waste, especially in landfills. Two significant landfill constituents come from textile waste and discarded plastic bottles. Since there is a finite amount of space that can be feasibly used for landfills, solutions that make use of these post-consumer products are imperative. This study presents one possible solution by using surface modifications of cotton fibers to produce a natural fiber-reinforced polymer composite (NFRPC) from post-consumer textile waste and polyethylene terephthalate (PET) …

Interference Mitigation Of Adjacent Radio Frequency Signals On A Flexible Software-Defined Radio Testbed Platform, Mirza Mohammad Maqbule Maqbule Elahi

Open Access Theses & Dissertations

The radio frequency (RF) spectrum is crowded with users and adjacent frequency users are facing an increase in interference from each other. The spectrum governing body Federal Communications Commission (FCC) has the difficult task of allocating spectral bands for new users for mobile devices using 4G LTE technology. Telemetry is affected by the adjacent band 4G LTE users in terms of signal degradation. To minimize the interference between adjacent frequency users, several methods can be used. A common but inefficient method separates adjacent band frequencies using guard bands which leaves a big portion of the spectrum unused. Alternatively, adjacent RF …

Impact Of Temperature And Screw Speed On Material Meso-Structure And Tensile Strength In Large Area Pellet-Fed Additive Manufacturing, Xavier Jimenez Guzman

Open Access Theses & Dissertations

Evolution in additive manufacturing, specifically in material extrusion, has resulted in large-scale machines capable of extruding thermoplastic-matrix composite materials in higher volumes to fabricate products for large-scale applications. As with small- and medium-scale material extrusion, the properties of the final product often correlate directly with the bevy of print parameters employed. The current research was performed to evaluate the effects of the screw speed and temperature on an ABS 20%wt. carbon fiber thermoplastic processed on a Big Area Additive Manufacturing (BAAM, Cincinnati Inc) machine. Five screw speeds (50, 150, 250, 350 and 400 rpm) and three extruder temperature profiles were …

Small Satellite Development At Utep, Emily Herzog

Open Access Theses & Dissertations

The small satellite industry has seen tremendous growth in recent years. A CubeSat is a particular type of standardized small satellite that follows the CubeSat specifications. These specifications define the structural, testing, and operational requirements of the satellite. This standard facilitates cheaper design, integration, and launch of satellites, allowing smaller organizations to participate in the normally costly area of space exploration.

The University of Texas at El Paso has recognized the opportunity and has begun developing several CubeSats. The two that are the topic of this Thesis are called Orbital Factory II (OFII) and Orbital Factory X (OFX). An on-orbit …

An Alternative Method Of Calibration And Prediction For The Theta-Projection Model, Jimmy Jesus Perez

Open Access Theses & Dissertations

The combustion induced high temperature-stress conditions of industrial gas turbines used in power generation causes turbine blades to wear and break after prolonged use. The need to predict turbine blade service life is ever increasing, leading to the development of several constitutive prediction models. It is necessary to design components for high-temperature/high-stress service such that creep failure does not occur during service life. For this reason, it is important to accurately predict creep life and understand the behavior of creep deformation leading to rupture. Several models have been expanded upon to improve their effectiveness for use with particular parametric data. …

Synthesis, Characterization And Antibacterial Properties Of Silver(I) N-(4-Pyridyl) Benzamide Complexes With Varying Conterions, Mauro J. Ruiz

Open Access Theses & Dissertations

Organic semiconductor materials composed of - stacking aromatic compounds have been under intense investigation for their potential uses in flexible electronics and other advanced technologies. Herein we report a new family of seven - stacking compounds of Silver(I) N-(4-pyridyl) Benzamide with varying counterions, namely [Ag(NPBA)2]X, where NPBA is N-(4-pyridyl) Benzamine, X = NO3- (1), ClO4- (2), CF3SO3- (3), PF6- (4), BF4- (5), CH3PhSO3- (6), and PhSO3- (7), which form extended - stacking networks in one-dimensional (1D), 2D and 3D directions in the crystalline solid-state via the phenyl moiety, with average inter-ring distances of 3.823 Å. Interestingly, the counterions that contain …

Adaptive Microphone Array Systems With Neural Network Applications, Jazmine Marisol Covarrubias

Open Access Theses & Dissertations

A microphone array integrated with a neural network framework is proposed to enhance and optimize speech signals derived from environments prone to noise and room reflections that cause reverberation. Microphone arrays provide a way to capture spatial acoustic information for extracting voice input from ambient noise. In this study, we utilize and analyze established signal processing methods combined with different neural network architectures to achieve denoised and dereverberated speech signal results that are comparable with their clean, anechoic versions. The first stage of the proposed system involves using datasets containing anechoic speech recordings of speech utterances and convolving them with …

Energy Management And Control Of Smart Power Distribution Systems, Eric Galvan

Open Access Theses & Dissertations

With the development of distributed energy resources (DERs) and advancements in technology, microgrids (MGs) appear primed to become an even more integral part of the future distribution grid. In this transition to the smart power grid of the future, MGs must be properly managed and controlled to allow efficient integration of DERs. Over the past years, there has been rapid adoption of roof-top solar photovoltaic (PV) and battery electric vehicles (BEVs). Although roof-top solar PV and BEVs can provide environmental benefits (e.g., reduction of emissions), they also create various challenges for power system operators. For example, roof-top solar PV generation …

Decision Support Tools For Parking Management On University Campuses, Okan Gurbuz

Open Access Theses & Dissertations

University campuses generate and attract trips with unique characteristics. Most universities are constantly challenged by the parking congestion issues. To manage campus parking infrastructure, most universities have established parking departments. This department is referred as the University Parking Office (UPO) in this Dissertation. There is no methodology or tool to assist the UPOs in their decision-making process. This Dissertation focuses on student parking and has developed models and methodologies as decision support tools to assist UPOs in managing student parking on campuses.

This Dissertation answers six Research Questions related to parking management on university campuses: (1) How many students are …

System Dynamic Model Of 1-Dimensional Unsaturated Water And Solute Transport For Predicting Salinity Stress In Crops, Thomas Poulose

Open Access Theses & Dissertations

There is a complex non-linear system dynamic between the water and salt transport in the unsaturated vadose zone where the salt transport and accumulation affect the water fluxes and vice versa. In addition, factors such as precipitation, transpiration, water infiltration and solute transport in the unsaturated zone of subsurface soil further complicate the processes involved. We have developed a system dynamics model for simulating the one-dimensional unsaturated water and solute transport along with root water uptake in the vadose zone. The model uses finite difference method for solving Richard's equation with a sink term for water transport and root water …

Tailoring Physical Properties Of Shape Memory Polymers For Fdm-Type Additive Manufacturing, Paulina Aileen Quinonez

Open Access Theses & Dissertations

Shape memory polymers (SMPs) have found applicability in biomedical settings as well as other uses that can take advantage of objects that can change shape upon exposure to stimulus. Integrating polymers with shape memory characteristics into additive manufacturing technologies such as fused deposition modeling (FDMâ?¢) can increase the number of applications this manufacturing platform can be utilized. Currently, polyurethane and polylactic acid (PLA) are two FDMâ?¢-compatible materials that possess shape memory properties. On their own these materials do not have tunable shape memory properties, namely shape recovery and shape fixation. The work presented here entails the development and characterization of …

Artificial Intelligence In The Assessment Of Transmission And Distribution Systems Under Natural Disasters Using Machine Learning And Deep Learning Techniques In A Knowledge Discovery Framework, Rossana Villegas

Open Access Theses & Dissertations

Warming trends and increasing temperatures have been observed and reported by federal agencies, such as the National Oceanic and Atmospheric Administration (NOAA). Extreme-weather events, especially hurricanes, tornadoes and winter storms, are among the highly devastating natural disasters responsible for massive and prolonged power outages in Electrical Transmission and Distribution Systems (ETDS). Moreover, the failure rate probability of any system component under extreme-weather tends to increase in the impacted geographic area. This Dissertation proposes an Artificial Intelligence (AI) Decision Support System that can predict damage in the ETDS and allow operators to mitigate disastrous extreme weather events. The document reports the …

Towards Analytical Techniques For Systems Engineering Applications, Griselda Valdepeñas Acosta

Open Access Theses & Dissertations

One of the main objectives of systems engineering is to design, maintain, and analyze systems that help the users. To design an appropriate system for an application domain, we need to know: what are the users' desires and preferences (so that we know in what direction we should aim to change this domain), what is the current state and what is the dynamics of this application domain, and how to use all this information to select the best alternatives for the system design and maintenance. Designing a system includes selecting numerical values for many of the parameters describing the corresponding …

Cmas/Volcanic Ash Infiltration Performance Of Yttria Rich-Zirconia Thermal Barrier Coatings Produced By Electron Beam Physical Vapor Deposition, Juan Jose Gomez Chavez

Open Access Theses & Dissertations

For many years the use of thermal barrier coatings (TBC) in gas turbine engines has allowed a significant increase in engine operating temperatures which are above the Ni-based super alloys' melting point. The base material for TBCs is the state of the art 7 wt % yttria stabilized zirconia (YSZ) which provides the thermal protection. Current industry demands for increased engine efficiency has pushed TBCs to the limits where significant technological constrains have been identified. One of the main ones represents the high temperature corrosion of the TBC material due to the ingestion of silicate based airborne particles commonly referred …

Image Analysis For Lung Cancer Diagnosis And Superresolution Localization Microscopy, Xia Huang

Open Access Theses & Dissertations

With the development of imaging analysis techniques, flurry of applications associated with it has been hatched. In this paper, image analysis on both organ and cellular levels will be demonstrated. For organ level images, a deep learning based computer aided lung cancer diagnosis based on computer tomography images is studied. Deep learning techniques have been extensively used in computerized pulmonary nodule analysis recent years. Many reported studies still utilized hybrid methods for diagnosis, in which convolutional neural networks (CNNs) are used only as one part of the pipeline, and the whole system still needs either traditional image processing modules or …

Structures And Daq System For The Lox/Lch4 500 And 2000 Lbf. Rocket Engines, Rachel Pilgrim

Open Access Theses & Dissertations

With the progression of space exploration and research, new alternative fuels and fuel combinations have been discovered. The ability to produce methane from Mars' atmosphere and oxygen from Mars' regolith has led to the two becoming a great alternative propellant combination for rocket propulsion systems. To further advance LOX/LCH4 propulsion systems, a 500 and 2000 lbf rocket engine were designed and manufactured and are to be launched from the MIRO cSETR Technology Research and Innovation Acceleration Park (tRIAc) in Fabens, Texas for data collection and analysis. The objective of this thesis is to give a thorough overview of the static …

Structural Design Of Complex Components, Armando Antonio Ochoa

Open Access Theses & Dissertations

The University of Texas at El Paso (UTEP) and the Center for Space Exploration and Technology Research (cSETR) is determined to develop a launch vehicle that is made completely of additive manufacturing materials, has the capability to transport a 100 lb payload to low earth orbit (LEO) as well as completing the design of a strucutral steel mobile launch stand that has the capability of withstanding the launch vehicle's static and dynamic loadings. The project will consist of carbon composite components to reduce weight while maintaining efficiency, strucutral steel components to resist extreme loadings and maintain strucutral shape, and lastly …

Exploration And Optimization Of Biomaterials And Cells Required For The Fabrication Of A "Cardiac Patch", Shweta Anil Kumar

Open Access Theses & Dissertations

Cardiac failure induced by myocardial infarction is believed to be one of the primary causes of morbidity and mortality all over the world. Affecting more than 26 million people worldwide, its prevalence has been observed to increase steadily. Myocardial infarction, which intitially begins as the occlusion of of a coronary artery, results in the death of millions of cardiomyocytes by obstructing blood flow to the serviced regions of the myocardium. The dead myocardium is replaced by a dense,collagenous scar which reduces the contractility of the heart, gradually leading to heart attacks. Most of the existing treatment therapies are palliative in …

Quantifying Early-Age Concrete Mechanical Properties And Curing Conditions Utilizing An Automated System, Benjamin Arras

Open Access Theses & Dissertations

The validation of concrete quality based on the 28-day strength is a lengthy process. Predicting concrete mechanical properties through early-age methods can streamline the construction process. Early-age concrete behavior consists of assessing the concrete curing as-related to setting stages, the hydration process, strength and stiffness development, while considering various environmental system parameters. This paper reports on a nondestructive method for observing the early-age strength and modulus development of concrete mixes over seven days in a controlled, laboratory setting. An apparatus was designed and built for continuous acquisition of seismic modulus data (using free-free resonant column) and heat of hydration/maturity information …

Bioprinted Mcf7 Breast Cancer Cells, An In Vitro Model For Drug Discovery, Aleli Campbell

Open Access Theses & Dissertations

Current breast cancer treatments are successful in eradicating this disease in the majority of patients, though there are quite a few cases where relapse or recurrence follow, which may lead to continued cancer therapy or death. Thermal inkjet bioprinting (BP) is a novel technique that is used to bioprint biomaterials or diverse cellular organisms to engineer tissue or organ models in vitro. In this Dissertation, we investigated the molecular effect of BP MCF7 breast cancer cells (BCC), cell survival of the cells when exposed to FDA approved systemic therapy alone and in combination with radiation and lastly, the ability of …

A Modified Wilshire Model For Creep Deformation And Damage Prediction, Jaime Aaron Cano

Open Access Theses & Dissertations

In this work, a new constitutive model, the WCS model, is derived that combines the Wilshire equations with continuum damage mechanics (CDM) for the long-term prediction of creep deformation, damage, and rupture. Long-term creep data is expensive and time-consuming to obtain because conventional creep testing is real-time. There is a need to extrapolate long-term creep behaviors from short-term data. Models that can accurately predict long-term creep behavior over a wide range of boundary conditions are vital for design engineers. The classic Wilshire equations can accurately extrapolate the long-term stress-rupture, minimum-creep-strain-rate, and time-to-strain of various alloys as their functional form has …

Assessing Spatiotemporal Exposures To Transportation Pollutants In Near-Road Communities Using Aermod, Mayra Consuelo Chavez

Open Access Theses & Dissertations

Traffic-related air pollution has a profound impact on human health especially for residents living in near-road communities which are constantly exposed these air pollutants. A near-road community is expected to observe significant spatial and temporal variations in pollutant concentrations, as air pollution resulting from emissions from major highways decreases rapidly from the highway. This research conducted on-site traffic and air quality measurements on four critical transportations related air pollutants, PM2.5, PM10, NO2, O3, as well as emission and air dispersion modeling of transportation emission impacts in a near-road community. Using numerical models provided by the EPA, integrated with field measurements …

A Method For Iron Determination During Copper Electrometallurgy And Its Application To The Calculation Of Current Efficiency, Daniel Pedro Cruz

Open Access Theses & Dissertations

With the objective of developing statistical models that describe iron kinetics under typical copper electrolytes as well as its effects on current efficiency and influence in cathodic and anodic behavior, a detailed electrochemical analysis is done in this work as a contribution to implement hydrometallurgical processes in the refining or winning process to produce high purity copper.

This Thesis evaluates the oxidation-reduction potential (ORP) of the Fe3+/Fe2+ couple in the H2SO4-Fe2(SO4)3-FeSO4-H2O and H2SO4-CuSO4-Fe2(SO4)3-FeSO4-H2O systems, with addition of different copper concentrations and temperatures up to 70°, typically employed in the industry. This study further validates and expands a thermodynamic expression developed …

Development Of An Ionic Green Monopropellant 1 Newton Thruster For Small Satellite Application, Jaclyn Mona Mejia

Open Access Theses & Dissertations

In effort to advance green monopropellant propulsion using AF-M315E, a 1N thruster was developed to demonstrate the propellant capabilities for low thrust requirement missions. The current study presents the development of a 1 Newton thruster. The thruster was designed based on available literature for initial parameters. In house developed catalyst was packed into the 1 Newton thruster, and mounted onto a thrust stand for testing. Two configurations of catalyst were used for this testing campaign. As a result, temperature peaks from AF-M315E decomposition gases reached up to 1400°C with an iridium loading factor of 25% by mass with both catalyst …

Platelet Biology And Thrombosis: Juul E-Cigarette Exposure And 5ht2a Receptor Drug Discovery, Jean Emmanuel Montes Ramirez

Open Access Theses & Dissertations

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The Drones' Impact On Precision Agriculture, Ibrahim Naji

Open Access Theses & Dissertations

A study to assess the overall impact of drones in the agricultural sector. The specific goal of this research was to provide a drone system to ward off pestering birds from crops to allow for better growth and an increased yield. Along with providing a user-friendly coded drone system for farmers that is cost effective, this project has inspired other areas of use for the drone.

Hfo Detector Based On Eeg Mean Energy Change Detection, Raul Ontiveros

Open Access Theses & Dissertations

The main goal of this work is to support automated seizure prediction by identifying preictal states using multiple detectors of high-frequency oscillations (HFOs). Assessment of HFOs from a seizure onset zone may be facilitated using automatic HFO detectors. However, studies have shown that HFOs can be generated by physiological or pathological brain processes. Distinguishing between pathological and physiological HFOs is challenging due to a lack of discriminant information in signals' morphology and other characteristics. Other complicating factors include a lack of consistency in definitions of HFO frequency ranges, the need for expert verification of HFO detection, and lack of robustness …

Magnetic Nanoparticles For Hyperthermia For Cancer Treatment, Bianca Paola Meneses Brassea

Open Access Theses & Dissertations

Fe3O4 and NixCu4-x magnetic nanoparticles were synthesized using supercritical conditions of liquids and wet chemistry, respectively. Characterization methods (VSM, SEM, TEM, and magnetic hyperthermia) yielded results that prove feasibility for magnetic hyperthermia for cancer treatment.