Engineering Commons^™

Real-Time Intelligent And Multi-Spectral Inspection Of Structural Components, Mst Mousumi Rizia

Open Access Theses & Dissertations

Conventional, manual inspection methods are the most commonly used inspection approaches to this day; that cause downtime and can be erroneous due to their repetitive nature, heavy workload, and human error. The overarching goal of this work is to advance structural inspection with intelligent and autonomous techniques across infrastructures. In particular, this project will develop path-planning schemes for close navigation around the structures and intelligent algorithms for crack and corrosion detection.

The introduced novel navigation method uses advanced manufacturing techniques to generate aerial inspection trajectories in GPS-denied areas. The proposed method is validated using the `Gazebo' robotics simulator; the results …

Emocolor : Fine-Grained Emotion Recognition From Skin Color Information, Maria Guadalupe Jimenez Velasco

Open Access Theses & Dissertations

In everyday human-to-human communication, emotions play a fundamental role. Emotions represent the affective behavior of humans that is multi-modal, subtle, and complex. Previous approaches based on conventional computer vision explicitly used shape information. Modern approaches based on deep learning implicitly exploit all information available in the image, but by their nature make it difficult to assess the contributions of each source of information. In addition, skin color as a unimodal technique to recognize emotions has been explored to recognize only three coarse-grained emotions in valence space.To the best of our knowledge, this work presents the first approach to fine-grained emotion …

Application Of Compressive Sensing To Microwave Tomography, Rafael Gerardo Lopez

Open Access Theses & Dissertations

Microwave tomography(MT) allows the safe, non-intrusive examination of the internal structureof an object by irradiating it with microwave signals and measuring how they get attenuated and diffracted as they propagate through the object. Measurement of these signals is difficult and slow, it depends on the objectâ??s physical properties and the test setup used for this. MT is based on a scanning process that yields measurement data with unique characteristics that make it difficult to process using standard computational methods. As the number of measurements needed for an image with acceptable resolution increases, the complexity of processing all the data becomes …

Evaluating Flow Features For Network Application Classification, Carlos Alcantara

Open Access Theses & Dissertations

Communication networks provide the foundational services on which our modern economy depends. These services include data storage and transfer, video and voice telephony, gaming, multimedia streaming, remote invocation, and the world wide web. Communication networks are large-scale distributed systems composed of heterogeneous equipment. As a result of scale and heterogeneity, communication networks are cumbersome to manage (e.g., configure, assess performance, detect faults) by human operators. With the emergence of easily accessible network data and machine learning algorithms, there is a great opportunity to move network management towards increasing automation. Network management automation will allow for a reduced likelihood of human …

A Survey Of The Current State Of The Practice In Bridging The Gap Between Engineering Ontologies And Modeling Profiles For Engineering Applications, John Artus

Open Access Theses & Dissertations

Model-Based Systems Engineering holds the promise of enhancing systems engineering tasks and product quality through better, more efficient exchange of data across tools, personnel, and departments, a higher quality of analysis resulting from greater access to cross-discipline data, better coordination between engineering activities and those of program management, and many other benefits. Yet, there is still no standardized method for achieving commonality of architecture vocabulary across projects, across, companies, across industries such that entities operating in the same domain produce products that speak the same technical language. Some specialized domains, such as the Department of Defense (DoD), have developed Architecture …

The Effect Of K2co3 Concentration In Kerosene Emulsions On Spray Droplet Sizes For A Magnetohydrodynamic Power Generator, Alejandra Castellano

Open Access Theses & Dissertations

Potassium carbonate (K2CO3) is an effective seeding material to introduce potassium vapor in oxy-fuel combustion to create a conductive plasma. Injecting potassium carbonate before combustion promotes particle volatilization and improves the generation of potassium vapor. This can be achieved by emulsifying a potassium carbonate solution with kerosene. Several studies have investigated creating stable emulsions with kerosene with water by using differing surfactants. However, the effects of using varying concentrations of K2CO3 dissolved in deionized water have not been fully explored. Based on methods of creating successful emulsions, the development of a successful mixture comprised of kerosene and K2CO3 solution is …

Structural Analysis Of Deformed Caprock Associated With A Salt Shoulder At Gypsum Valley Salt Wall, Paradox Basin, Colorado, Hanah Draper

Open Access Theses & Dissertations

This study documents the style and distribution of deformation present in Triassic-age gypsic and carbonate caprock associated with the Gypsum Valley Salt Wall Salt Shoulder in the Paradox Basin, Colorado in order to determine the mechanism and timing of deformation. Mapping of gypsic and carbonate capstone facies shows that the caprock layering that was generated during formation has been deformed by large-and-small-scale folding and faulting, brecciation, and boudinage. Deformation within the caprock resulted in widely variable orientations along the length of the salt shoulder, that also varies locally in intensity of deformation and with proximity to the passively rising diapir …

Extracting Mechanical Properties Of Compacted Geomaterials Using Intelligent Compaction Technology, Aria Fathi

Open Access Theses & Dissertations

The primary tool currently used for quality management of earthwork and unbound aggregates is the nuclear density gauge (NDG) to ensure appropriate density and moisture content. Measurement of moisture content and dry density, even though quite practical and straightforward, does not directly tie the construction quality with the mechanistic-empirical design processes where stress and modulus are employed. With the recent popularity of the mechanistic pavement design procedures, research efforts have been undertaken to understand and develop procedures for implementing modulus-based quality control (QC) procedures of compacted geomaterials. These procedures involve the use of in-situ nondestructive testing (NDT) devices that estimate …

Machine Learning Analysis To Characterize Phase Variations In Laser Propagation Through Deep Turbulence, Luis Fernando Rodriguez Sanchez

Open Access Theses & Dissertations

The present Dissertation is focused on the analysis of the atmospheric conditions of a turbulent environmental system and its effects on the diffraction of a laser beam that moves through it. The study is based on the optical communication of two labs placed at the summit of two mountains located in Maui, Hawaii. The emitter system is located at the Mauna Loa mountain and the receiver at the Haleakala. The distance between both mountains is 150 km. The emitter system is at a height of 3.1 km and the receiver at 3.4 km. The maritime environment at the location experiences …

Development Of A Framework For The Calibration Of Rpas, A 3d Finite Element Analysis Tool For Rigid Pavements, Abbasali Taghavighalesari

Open Access Theses & Dissertations

The accurate analysis of rigid pavements requires a reliable modeling procedure based on integrating mechanistic analysis methods (i.e. closed-form solutions or numerical methods) and empirical observations (i.e. field measurements and laboratory test results). The use of the finite element method to model the response of rigid pavements has increased in recent decades due to its capability to incorporate the complexity of material behavior, traffic information, and environmental condition. Researchers from the University of Texas at El Paso developed the software Rigid Pavement Analysis System (RPAS) to comprehensively analyze the response of concrete pavements under different geometric configurations, foundation models, temperature …

Photovoltage Enhancement For Stable Perovskite Solar Cells With A Temperature-Controlled Grain Growth Technique, Luis Eduardo Valerio

Open Access Theses & Dissertations

By performing strong characterizations methods, one can begin to fully understand the chemistry and composition behind a great performing perovskite solar cell. Understanding how the interaction between layers inside a solar cell is driven by the temperature and overall environment is a key element to improve the fabrication process and overall efficiency of such cells. This Thesis will present a study of the hybrid organic-inorganic, mixed-cation, mixed-halide, temperature and thickness-controlled perovskite solar cell. A constant power conversion efficiency (PCE) ranging between 15-17% and an open circuit voltage V¬oc above 1.05 V for a wide-band gap perovskite cell is presented.

A Probabilistic Creep Constitutive Model For Creep Deformation, Damage, And Rupture, Md Abir Hossain

Open Access Theses & Dissertations

The structural analysis of Industrial Gas Turbine (IGT), Aeroengine, Gen IV nuclear components under in-service conditions at various stress and temperature are susceptible to time-dependent creep deformation and creep induced failure. Such failure phenomena are exacerbated by the randomness in material properties, oscillating loading conditions, and other sources of uncertainty. The demand for physically based probabilistic creep modeling is highly sought by alloy designers. The objective of this study is to develop and validate a probabilistic creep-damage model incorporating multi-sources of uncertainty to replace the traditional deterministic and empirical decision-based modeling. In this study, the deterministic Sine-hyperbolic (Sinh) creep-damage model …

Evaluation And Modeling Of Electrodialysis For High-Recovery Brackish Water Desalination, Shahrouz Jafarzade Ghadimi

Open Access Theses & Dissertations

This research investigates the feasibility of desalination of brackish water with electrodialysis (ED), using laboratory testing and mathematical modeling. Several experiments were performed to characterize ion-specific transport and to evaluate tradeoffs between salinity removal and specific energy consumption. A 200 cm2 Ameridia ED stack was used to perform desalination experiments with real brackish groundwater from the Kay Bailey Hutchison desalination plant in El Paso, Texas, and the results showed limiting current density of 160 A/m2 for 5 cm/s. A higher conductivity reduction was observed for flow velocity of 5 cm/s compared to 13 cm/s. Ion transport selectivity (based on relative …

High Pressure High Heat Flux Pool Boiling Test Facility Design To Investigate Nucleation Boiling Heat Transfer Enhancement Using Micro/Nano-Scale Engineered Structures, Omar Hernandez Hernandez Rodriguez

Open Access Theses & Dissertations

Developing efficient heat dissipation technologies is of critical importance towards the development and the commercialization of next-generation compact and high-performance electronic devices, cooling systems, power generation systems and chemical processing units, as well as retrofitting the existing thermal management schemes. As such, phase change heat transfer systems, more specifically boiling heat transfer systems, have attracted significant attention due to their ability to extract a large amount of latent energy stored within the fluid. Pool boiling is an efficient mode of phase change heat transfer processes accompanied by nucleation of vapor bubbles from liquid on to the hot surfaces, bubble growth, …

Relating Surface Resistivity To Corrosion Of Rebar Embedded In Portland Cement Concrete, Luisa Alejandra Morales

Open Access Theses & Dissertations

Reinforced concrete is widely used as a construction material known for its durability and proficiency of withstanding large forces in severe environments. Despite that the majority of these structures result in long-term performance, there is still a large number of failures of reinforced concrete structures as a result in corrosion of the reinforcement and concrete degradation. It is critical to assess the state of the corroded structure to decide on whether maintaining or replacing the structure is needed. The objective of this study is to characterize a relationship between the steel reinforcement corrosion and the concrete's resistivity. It is widely …

Development Of A Multi-Axis Wire Embedding Device For A Large Area Thermoplastic Pellet-Fed Additive Manufacturing System, Christopher Jasiel Minjares

Open Access Theses & Dissertations

This research focused on the development and implementations of a six degrees of freedom (6DOF) articulated arm onto a Big Area Additive Manufacturing (BAAM) system to interact with complex 3D geometries. BAAM is a large-scale machine which falls under material extrusion additive manufacturing (AM) - a process that selectively dispenses molten plastic layer-by-layer. The development of the 6DOF articulated arm required a mechanical design which went through several iterations before getting to the final design. Also, implementation of the tool was performed with the help from Cincinnati Incorporated (CI) which is the company that developed the BAAM.

First, the mechanical …

Oxidation Of Niobium Silicides Obtained By Self-Propagating High-Temperature Synthesis, Frank Anthony Perez

Open Access Theses & Dissertations

Niobium silicide-based composites are promising materials for high-temperature structural applications, such as gas turbines. One attractive method for their fabrication is mechanically activated self-propagating high-temperature synThesis (MASHS). However, oxidation resistance of niobium silicides produced by MASHS has not been studied yet. In this present work, the oxidation of Nb/Nb5Si3 composites obtained by MASHS was investigated by using non-isothermal thermogravimetric analysis (TGA) and differential scanning analysis (DSC). Both techniques have shown that the oxidation starts at about 500 °C and the materials become fully oxidized at 750 â?? 800 °C. Model-based analysis of the TGA data has shown that the Avrami-Erofeev …

Multi-Wavelength Pyrometry For Emissivity Mapping And Accurate Surface Temperature Measurement In Powder Bed Fusion Systems, Md Moinuddin Shuvo

Open Access Theses & Dissertations

Accurate surface temperature measurement within powder bed fusion (PBF) systems during fabrication remains elusive for many reasons, despite the importance of knowing temperature for improving part quality, process control, repeatability and reproducibility, simulation capabilities, and more. Multi-wavelength (MW) pyrometry has been used previously to measure off-axis temperatures of a small region (~2.6mm in diameter) within an electron beam PBF (EBPBF) system. While this small region measurement makes it difficult to get a full field temperature map of the powder bed, it also allows for inline (on-axis) with laser temperature measurements for laser PBF (LPBF) systems. The MW pyrometry technique determines …

Brian Valdez - Dynamics And Control Of A 3-Dof Manipulator With Deep Learning Feedback, Brian Orlando Valdez

Open Access Theses & Dissertations

With the ever-increasing demands in the space domain and accessibility to low-cost small satellite platforms for educational and scientific projects, efforts are being made in various technology capacities including robotics and artificial intelligence in microgravity. The MIRO Center for Space Exploration and Technology Research (cSETR) prepares the development of their second nanosatellite to launch to space and it is with that opportunity that a 3-DOF robotic arm is in development to be one of the payloads in the nanosatellite. Analyses, hardware implementation, and testing demonstrate a potential positive outcome from including the payload in the nanosatellite and a deep learning …

Early Detection Of Asthma Via Enhanced Resolution Of Small Airways Using Ultra-Low Frequency Impulse Oscillometry, Christopher M. Aguilar

Open Access Theses & Dissertations

Examination of lung function for diagnosis and monitoring of diseases such as chronic obstructive pulmonary disease (COPD) and asthma can be performed with a variety of pulmonary function testing (PFT) techniques. The most commonly prescribed of these procedures are spirometry and whole-body plethysmography. However, these active participation tests depend on forced breathing maneuvers, may be physically exhausting, might not produce enough information, and are susceptible to being subject-dependent. In contrast, passive PFT approaches such as the forced oscillation technique (FOT) and the impulse oscillometry system (IOS) are increasingly being utilized for measuring lung mechanics because they require only minimal participation, …

Assessment Of Hydraulic And Structural Behavior Of Inundated Pavements, Mojtaba Asadi

Open Access Theses & Dissertations

Severe flooding events have increasingly inundated the transportation infrastructure, including road networks, across the world and the Unites States. Such extreme events induce significant ingress of water into the pavement layers, which in turn leads to structural defects due to the reduction of the shear strength and resilient moduli of the soil layers, asphalt stripping in flexible pavements, pumping effect in rigid pavements, migration of fines into drainable layers, and swelling of expansive soils. Consequently, premature pavement failure may take place that can impose unforeseen maintenance/rehabilitation costs to highway agencies. Although some experimental research studies have been conducted to assess …

Low Weight Design Of A Pressure-Fed System For A Small Payload Launch Vehicle, Lucero Buendia

Open Access Theses & Dissertations

Carbon fiber reinforced polymer (CFRP) composites have become of great interests to aerospace industries because of their low-cost, lightweight and their tailorable mechanical properties. In aerospace structures, for example, heavy metals have been used in cryogenic fuel and oxidizer tanks for over 50 years. However, weight savings can be substantial if materials such as composites are used instead. From Delta IV heavy-lift launch vehicle it is known that cryogenic composite tanks can save approximately up to 30% of weight in fuel and oxidizer tanks. Although there is a wealth of studies in the mechanical behavior of composites at room temperature, …

Formulation Strategies To Enhance Solubility And Permeability Of Small Molecules For Drug Delivery Applications, Pradeep Kumar Bolla

Open Access Theses & Dissertations

All the new chemical entities/drug molecules intended for therapeutic use must be administered using an appropriate delivery system/dosage form to achieve maximum bioavailability. However, designing a drug delivery system is complex as several factors such as lipophilicity, molecular mass, crystallinity, ionic charge, polymorphic forms and hydrogen bonding) affect the solubility and permeability of these molecules. Biopharmaceutics drug classification system (BCS) categorizes the existing drugs into four classes based on the aqueous solubility and membrane permeability and it is reported that >70% of the drugs are poorly soluble and belong to BCS class II and BCS class IV. Several physical, chemical …

Structure-Property-Performance Evaluation Of Refractory Metal Incorporated Gallium Oxide Thin Films For Extreme Environment Applications, Anil Krishna Battu

Open Access Theses & Dissertations

An approach is presented to design refractory-metal (RM) incorporated Ga2O3-based materials with controlled structural, mechanical, and optical properties. A model system based on molybdenum (Mo) doped Ga2O3 (GMO) has been considered to elucidate the combined effect of RM-doping and processing parameters on the properties and oxygen sensor performance of GWO nanomaterials. The molybdenum (Mo) content in Ga2O3 was varied from 0 to 11 at% in the sputter-deposited Ga-Mo-O films. Molybdenum was found to significantly affect the structure and optical properties. While low Mo content (≤4 at%) results in the formation of single-phase (β-Ga2O3), higher Mo content results in amorphization. Chemically …

Supercritical Processed Decellularized Extracellualr Matrix As Regeneration Therapeutics Applying 3d Printing, Seungwon Chung

Open Access Theses & Dissertations

Extracellular matrix has been broadly applied and show great promise in medical applications and tissue engineering. Product of extracellular matrix (ECM) should be treated with decellularization and purification process. Supercritical carbon dioxide treatment is of particular interest for purifying ECM because of its medically available and rapid speed of process. However, it is not fully researched in treatment of biomaterials for tissue engineering. Therefore, we investigated optimal conditions of supercritical carbon dioxide processing in different extracting parameters from porcine adipose tissue. The 3-day, dual treatment including enzymatic decellularization and supercritical fluid extraction of pork adipose tissue were performed. Two types …

3d Printed Alginate-Based Zinc Oxide Nanoparticle Scaffolds For Wound Healing, Carol Cleetus

Open Access Theses & Dissertations

Effective treatment of chronic wounds is essential for the prevention of infection and scar tissue formation, requiring a novel approach to address the limitations of existing options. This study utilizes Calcium Chloride (CaCl2) crosslinked alginate, a common biomaterial widely used in wound dressing, and UV activated Zinc Oxide (ZnO) nanoparticles (NPs) for their potential hydroxyl radical mediated antibacterial applications. ZnO NPs were synthesized by combustion method from Zinc Nitrate Hexahydrate and Sucrose. Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) characterization were used to verify composition and NP size. Terephthalic Acid, used as a fluorescent probe, confirmed the generation of …

Regulation Of Schlafen 11 Expression, Christian Waldemar Corona Ayala

Open Access Theses & Dissertations

Schlafen 11 (SLFN11) is a member a family of proteins that can be found in mammals. Members of this family are involved in important functions. SLFN11 in particular has been identified as a restriction factor for several evolutionarily disparate viruses such as HIV-1 and Flaviviruses and to play an important role in DNA repair, sensitizing cells to chemotherapy. Despite its relevance SLFN11 remains largely uncharacterized. The aim of this research was to achieve a more comprehensive understanding the regulation mechanism of SLFN 11 expression. Before our research, it was only known that type I interferon (IFN) regulates SLFN11 levels. However, …

To Or Through The Skin: A Rational Design Of Transdermal Drug Delivery, Isaac Giovanni Deaguero

Open Access Theses & Dissertations

The skin is the largest organ in the body and plays many crucial roles through diverse functions ranging from protection, temperature regulation, energy storage via fat deposits, and is used to communicate with our surroundings. Various methods have been attempted to deliver drugs to target areas of the skin in effective dosages by a variety of means with limited success. Recently, advances in transdermal drug delivery have offered avenues previously unattainable through conventional means. Some of these new delivery methods have been reviewed, explored and offer promising results with the potential to carve a new avenue in the way therapeutic …

Development And Characterization Of Perovskite Solar Cells For Tandem Device Configuration, Angel Moiseis De La Rosa

Open Access Theses & Dissertations

Photovoltaic devices based on perovskite materials are constantly progressing towards more applicability in large-area panels. In order for perovskite-based photovoltaics to reach reliable and stable commercialization, common issues with the use of perovskite still need to be resolved, including the need to identify fabrication processes that can yield optimal material parameters for better photovoltaic performance. Defining an optimal fabrication process requires that researchers and manufacturers alike come to an agreement regarding perovskite characteristics that result from device operation and material processing. This work focuses on characterizing physical, electrical, and electronic properties of a FAxCs1-xPb(IyBr1-y)3 perovskite, and how some of these …

Thermoanalytical Studies On The Decomposition Of Energetic Ionic Liquids, Alan Esparza

Open Access Theses & Dissertations

Hydrazine has been extensively used as a propellant for space applications for more than half a century. However, its hazardous characteristics cause high storage and handling costs. For this reason, the search for alternatives, the so-called “green monopropellants,” is of great interest. Most green monopropellants are mixtures of an oxidizer and a fuel, and several ionic liquids (ILs) have been proposed for this application. Among them, hydroxylammonium nitrate (HAN) and 2-hydroxylethylhydrazinium nitrate (HEHN) are promising oxidizer and fuel, respectively. The objective of the present work was to clarify the decomposition kinetics of both HAN and HEHN, using thermogravimetric analysis (TGA), …