Engineering Commons^™

Role Of Mammary Microenvironment In Promoting Left-Right Differences In Tumor Progression, Metastasis, And Therapeutic Response, Huda Issa Atiya

Theses and Dissertations

Metastasis is the main cause of death in breast cancer patients; however, there are currently no treatments available to treat or prevent metastasis. This is in part because regulators of metastasis are not yet fully understood. Over the past century researchers began to study metastasis regulators by different hypotheses, such as the seed and soil hypothesis which focuses on studying the role of cancer cells, the seeds, and the tissue microenvironment, the soil, in regulating metastasis. Although lots of studies have focused on the microenvironment of metastatic sites and their roles in regulating metastasis, limited studies have focused on the …

Effect Of Material Orientation On The Impact Response Of Graded Cellular Materials, Abigail Wohlford

Theses and Dissertations

In this study, the effect of layer stacking on the energy absorption characteristics of density-graded cellular polymers subjected to high velocity impact is investigated experimentally. The focus in the present work is to characterize the constitutive response and deformation mechanisms of these Functionally Graded Foam Materials (FGFM) using full-field measurements. Uniform foam Quasi-static and dynamic testing of uniform foam specimens are completed for each nominal density used in the layered foam samples. The low strain-rate experiments are performed in order to determine the mechanical properties of foam specimens. The high-rate experiments for homogenous foam specimens were completed to further characterize …

A Comprehensive Reengineering Of The Hospital Emergency Triage System, Nicholas D. Boltin

Theses and Dissertations

Hospital emergency triage and specifically Mass Casualty Incidents (MCIs) are of major concern with regard to treatment and patient outcomes. Traditional emergency department triage models are oversimplified and often lead to over/under triaging of patients. Furthermore, triage models do not account for the full spectrum of different types of MCIs which often results in misclassification. In this thesis, we begin by looking at traditional triage models currently being used in hospital systems and identify several shortcomings of using these models within the context of a chemical related MCI. I will then move to describe a new approach to creating a …

Acoustic Emission Detection In 304h Stainless Steel Due To Intergranular Stress Corrosion Cracking, Joseph W. Hill

Theses and Dissertations

Storage of spent nuclear fuel has become problematic in past decades due to delayed completion of long-term repositories for various reasons. Temporary storage containers called Dry Cask Storage Systems (DCSS) made of stainless-steel and surrounded by reinforced concrete have been in use but are exceeding their designed usage periods. Defects in canisters can be exacerbated in climates susceptible to high humidity and salinity levels. As inspection and relicensing of DCSS increases, more efficient monitoring techniques could save nuclear facilities valuable time and resources. Crack detection of the canister walls or welds in real time may be possible utilizing acoustic emission …

Characterization Of Evaporation/Condensation During Pool Boiling And Flow Boiling, Mostafa Mobli

Theses and Dissertations

Present dissertation has investigated pool and flow boiling and their characteristics via numerical means. A code was developed to investigate and enhance heat transfer performance during different modes of phase change phenomena. Multiphase heat transfer has proven to be one of the most effective means of heat transfer in different industries, therefore, there have been numerous experimental and numerical studies on the subject of phase change phenomena in a wide range of conditions and setups; yet there are complex bubble dynamics and heat transfer characteristics that remain unresolved. To have a more detailed look at and a better understanding of …

Acousto-Ultrasonic Shm/Nde Methods Toward Field Application, Stephen Harris Howden

Theses and Dissertations

Acousto-ultrasonic nondestructive evaluation (NDE) and structural health monitoring (SHM) methods offers solutions in damage detection, material properties evaluation and more. These ultrasonic waves can propagate through solids and interact with structural features and discontinuities. In this thesis use of several acousto-ultrasonics NDE/SHM methods were explored to evaluate their sensing and detection capabilities toward damage detection field applications in nuclear and aerospace industries.

For nuclear applications, passive sensing using piezoelectric sensors and acoustic emission (AE) techniques were explored on the spent fuel dry storage casks. Dry storage casks are used in the nuclear industry to transport or store spent nuclear fuel …

High Resolution Radiation Detectors Based On 4h-Sic N-Type Epitaxial Layers And Pixilated Cdznte Single Crystal Devices, Cihan Oner

Theses and Dissertations

Silicon Carbide (SiC) is an indirect wide bandgap semiconductor with high thermal conductivity, high breakdown electric field, high carrier saturation drift velocity, and large displacement energy making it a suitable candidate for replacing conventional radiation detectors based on Si, Ge, CdTe, and CdZnTe (CZT). In this dissertation, fabrication and characterization of high-resolution Schottky barrier detectors for alpha particles using 20 µm thick n-type 4H-SiC epitaxial layers are reported. Schottky barriers were obtained by depositing circular nickel contacts of ~10 mm2 area.

Room temperature current-voltage (I-V) measurements revealed Schottky barrier heights of the order of 1.7 eV, ideality factor of ~1.1, …

Three-Way Catalysts In Passive Selective Catalytic Reduction Systems, Calvin Thomas

Theses and Dissertations

Conventional gasoline-powered engines operate with a stoichiometric air-fuel ratio (AFR), but greater fuel economy is achieved in lean burn engines by increasing the AFR. The primary drawback to these engines is the nitrogen oxide (NOX) emissions, which cannot be reduced over a conventional three-way catalyst (TWC). Passive selective catalytic reduction (SCR) is a promising approach for the control of NOX emissions in lean burn systems. By periodically decreasing the AFR to fuel-rich levels, ammonia (NH3) can be produced over a TWC and stored on a downstream SCR catalyst for the reduction of NOX during normal lean operation. While passive SCR …

Structural Health Monitoring Using Ultrasonic Guided Waves And Piezoelectric Wafer Active Sensors, Faisal Haider Mohammad

Theses and Dissertations

This dissertation is organized in three major parts covering ardent and challenging research topics in structural health monitoring (SHM). Part I focuses on the theoretical and numerical analysis of acoustic emission (AE) guided waves in both Cartesian coordinates (2D) and cylindrical coordinates (3D) system using energy approach, which, to the best of our knowledge, has not been yet reported elsewhere. AE guided waves appear due to sudden energy release during incremental crack propagation in a plate. The Helmholtz decomposition approach is applied to the inhomogeneous elastodynamic Navier-Lame equation for both the displacement field and body forces. For the displacement field, …

Probabilistic Multilevel Constitutive Model Of The Compressive Strength Of Hardened Cement Paste Reinforced With Mwcnts, Yohanna Mejia Cruz

Theses and Dissertations

Constitutive models available in the literature typically describe the compressive strength of ordinary Portland cement paste (OPC) in a deterministic fashion, in some cases as a function of variables such as W/C, porosity, and the clinker chemical composition. The significant effect of the proportion of W/C on the final strength, porosity and density have been reported in several works in material science. Some studies have shown that the addition of MWCNTs can also modify the microstructure of cement significantly, and improve compressive strength and other mechanical and physical properties. In principle, W/C, MWCNTs addition, porosity, density, and compressive strength are …

Meso-Scale Simulation Of Size-Dependent Shear Behavior In Glass Fiber Reinforced Polymer Reinforced Concrete Beams Without Stirrups, Sina Khodaie

Theses and Dissertations

There is extensive experimental evidence of the decrease in the shear stress at failure at increasing effective depths in concrete beams reinforced with glass fiberreinforced polymer (GFRP) bars without shear reinforcement. An important practical implication is that extrapolating strength values from typical laboratory-scaled experiments to design larger members may be misleading. The complexity of the underlying mechanics is reflected in the difficulty of using commercially available numerical tools to accurately estimate shear strength irrespective of beam size. This dissertation presents research on a Lattice Discrete Particle Model (LDPM) based model to simulate the response of scaled slender GFRP reinforced concrete …

Development Of Models And Solution Methods For Different Drayage Applications, Samaneh Shiri

Theses and Dissertations

In the last decades, intermodal freight transport is becoming more attractive in the global supply chains and freight transport policy makings. Intermodal freight transport provides a cost-effective, reliable, and efficient movement of freight by utilizing the strengths of different transport modes. The initial and final segment of intermodal freight transport, performed by truck, is known as “drayage.” The scheduling of truck movements in drayage operation within the service area of an intermodal terminal is an operational problem which leads to a truck scheduling problem that determines the efficient schedule of trucks while satisfying all transportation demands and constraints. Drayage accounts …

System Optimization And Material Development Of Solid Oxide Cells For Energy Conversion And Storage, Libin Lei

Theses and Dissertations

Solid oxide cells (SOCs) can convert chemical energy to electricity in the fuel cell mode and store electricity to chemicals in the electrolysis mode. However, there are still critical barriers, such as energy efficiency and durability, for the development and commercialization of SOCs. The objective of this dissertation is to apply system optimization and materials design to address the critical barriers for solid oxide cells in energy conversion and energy storage applications. One major focus of the dissertation is related to improve energy efficiency, enhance the cell performance and achieve multifunctionality in solid oxide electrolysis cells (SOECs). In addition, development …

Bytecode-Based Multiple Condition Coverage: An Initial Investigation, Srujana Bollina

Theses and Dissertations

Masking occurs when one condition prevents another condition from influencing the output of a Boolean expression. Logic-based adequacy criteria such as Multiple Condition Coverage (MCC) are designed to overcome masking at the within-expression level, but can offer no guarantees about masking in subsequent expressions. As a result, a Boolean expression written as a single complex statement will yield test cases that are more likely to overcome masking than when the expression is written as series of simple statements. Many approaches to automated analysis and test case generation for Java systems operate not on the source code representation of code, but …

Analysis Of Pellet-Cladding Mechanical Interaction On U3si2 Fuel With A Multi-Layer Sic Cladding Using Bison, Ray A. Freeman

Theses and Dissertations

U3Si2 is currently being considered as a possible replacement for the current light water reactor fuel, UO2. U3Si2’s high melting temperature, high uranium density, and high thermal conductivity are favorable in accident conditions, such as a loss of coolant accident. Improved accident performance is further expected when paired with a SiC/SiC cladding, since it provides relatively high strength and a high oxidation resistance.

Modeling of U3Si2 and SiC/SiC in reactor is currently very important since much of their behavior is still unknown. By implementing models that describe the properties of U3Si2 and SiC/SiC into INL’s fuel performance code BISON, performance …

Effect Of Weak Adhesion Interface On Mechanical And Dielectric Properties Of Composite Materials, Prashant Katiyar

Theses and Dissertations

Interfaces are often the most critical part of the heterogeneous materials and their structures. Such interfaces appear a multiple length scales and significantly affect bulk properties in different material systems. Fiber reinforced composite materials are one such example of heterogeneous materials with interfaces at constituent scale (fiber-matrix interface and interphase) to laminate scale (secondary adhesive joints). Manufacturing induced defects and subsequent in-service damage at these interfaces can severely affect the durability of fiber reinforced laminated composite materials and their joints. In addition to lamination process, defects can also form during secondary joining process (e.g., adhesive bonding and repair) which can …

Combustion Behavior Of Sub-Millimeter Sized Oxygenated And N-Alkane Fuel Droplets, Mohammad Fahd Ebna Alam

Theses and Dissertations

The primary scientific explorations of this thesis work are to better understand (a) microgravity fire-suppression of untested extinguisher, (b) combustion kinetic model refinement of renewable fuel butanol (C4H9OH) isomers, and (c) directly induced cool flame dynamics of higher n-alkane fuels from an isolated small droplet combustion perspective employing computational fluid dynamics with comprehensive chemical kinetics. The chronological development of the research direction shifts from a relatively small fuel like methanol (CH3OH) to heavier straight paraffinic fuel n-decane (n-C10H22). The first installment of the thesis is directed towards answering the feasibility of thennewly considered fire suppressant xenon (Xe) for microgravity space …

Understanding Early Amyloid-Ss Aggregation To Engineer Polyacid-Functionalized Nanoparticles As An Inhibitor Design Platform, Nicholas Vander Munnik

Theses and Dissertations

Alzheimer’s disease (AD) is characterized by the presence of amyloid-ß (Aß) protein aggregates in the brains of those afflicted. This protein aggregates via a complex pathway to progress from monomers to soluble oligomers and ultimately insoluble fibrils. Due to the dynamic nature of aggregation, it has proven exceedingly difficult to determine the precise interactions that lead to the formation of transient oligomers. A statistical thermodynamic model has been developed to elucidate these interactions. Aß was simulated using fully-atomistic replica exchange molecular dynamics. We use an ensemble of 5 × 105 configurations taken from these simulations as input for a self-consistent …

Hydrodeoxygenation Of Acetic Acid Using Monometallic And Bimetallic Catalysts Supported On Carbon, José Luis Contreras Mora

Theses and Dissertations

Heterogeneous catalytic hydrodeoxygenation (HDO) of biomass-derived feeds is a deoxygenation process that is of highly interest. Carboxylic acids are one of the main components of bio-oils and acetic acid is one of the most abundant of these carboxylic acids. This acid is rich in oxygen, therefore a lot of research to produce fuel and other valuable chemicals such as ethanol is of interest.

This dissertation explores the gas-phase catalytic HDO of AA over catalysts supported on activated carbon (Cp-97). Temperature-dependent conversion and selectivity were studied at 1 atm from 200-400⁰C with an AA concentration of 1.1% and 20% …

Tracking, Detection And Registration In Microscopy Material Images, Hongkai Yu

Theses and Dissertations

Fast and accurate characterization of fiber micro-structures plays a central role for material scientists to analyze physical properties of continuous fiber reinforced composite materials. In materials science, this is usually achieved by continuously crosssectioning a 3D material sample for a sequence of 2D microscopic images, followed by a fiber detection/tracking algorithm through the obtained image sequence.

To speed up this process and be able to handle larger-size material samples, we propose sparse sampling with larger inter-slice distance in cross sectioning and develop a new algorithm that can robustly track large-scale fibers from such a sparsely sampled image sequence. In particular, …

Development Of Bimetallic Catalysts For Dry Reforming Of Methane And Hydrogenation Of Succinic Acid, Jayson Michael Keels

Theses and Dissertations

Advances in natural gas recovery have greatly impacted the global economy; the abundant supply of gas has revealed new opportunities and challenges in a wide range of markets within the fuels and chemicals industries. One such opportunity exists with the overabundance of gas from remote wells that is flared or emitted because of the high costs associated with transportation of a chemical with such a high molar volume. A possible solution is an on-site process to convert gas to higher value chemicals that are liquid at standard conditions, and can more easily be transported. As a first step, CO2 from …

Design For Optical Metamaterial Design For Optical Metamaterial Absorber, Huixu Deng

Doctoral Dissertations

“Optical metamaterlal (MM) absorbers in the visible or near-infrared range have been widely investigated in these years since they are crucial in many promising applications, such as solar energy harvesting systems, thermo-photovoltaic energy conversion devices, thermal imaging and emissivity control. This dissertation aims to design and investigate various optical metamaterial absorbers based on different mechanisms and theories, such as cavity resonance, impedance match, equivalent circuit model and waveguide stop light mode. First, via utilizing the cavity resonance, a tunable narrowband MM absorber/emitter for thermophotovoltaic (TPV) is designed and analyzed based on gold nanowire cavities to improve the overall efficiency of …

Use Of A Dynamic Balance System To Quantify Postural Steadiness And Stability Of Individuals With Lower-Limb Amputation: A Pilot Study, M. Barbara Silver-Thorn Phd, Joel Kempfer, Alyssa J. Schnorenberg, Brooke Slavens

Biomedical Engineering Faculty Research and Publications

Introduction Despite rehabilitation and gait training, the gait of individuals with lower-limb amputation is often asymmetric and falls and/or fear of falling are common. Clinical assessments of balance and stability include the Berg BalanceScale and the Dynamic Gait Index. Biomechanical assessments, conducted largely in research laboratories, are more objective, quantitative, and may provide greater resolution. These biomechanical measures include postural sway during both unilateral and bilateral standing tasks and the dynamic postural response to applied or volitional perturbations. The objective of this study was to investigate the utility of a dynamic balance system, a relatively new clinical tool incorporating dual …

Inverse Kinematic Assessment Of Rehabilitative Therapy In Children Using Orthotics, Michael P. Murphy, Jacob R. Rammer, Kaleb L. Vinohout, Meghan R. Caballero, Christy M. Cornwell, Jessica M. Fritz, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Pathologic movement patterns are characterized by abnormal kinematics that alter how muscles support the body during walking. Individual muscles are often the target of interventions with physical therapy and surgery alike, yet the tools to assess individual muscles clinically remain limited. The aim of this study is to assess OpenSim as a clinical tool for individualized rehabilitative evaluation of children using orthotics. This anatomic and kinematic modeling study was focused on pre- and post-treatment assessment of gait characteristics in fourteen children using orthotic devices. A range of four to twelve acceptable gait capture trials was collected for each child before …

Micro-Slotting Technique For Measurement Of Local Residual Stress In Metallic Materials, Elizabeth Anne Burns

Doctoral Dissertations

"Micro-slotting, a micro-scale relaxation residual stress measurement technique, has been shown in recent years to be a reliable method for measuring local residual stresses in metallic materials. This technique employs an SEM-focused ion beam system for milling and imaging, digital image correlation software to track displacements due to residual stress relaxation, and finite element analysis for interpolation of the original local stress state. In this research, a micro-slotting procedure was established using finite element models and was used to obtain sub-surface residual stress measurements on machined and shot peened planar Ti-6Al-4V samples. These measurements were compared to macro-scale XRD residual …

Nondestructive Evaluation Of Corrosion Damage In Reinforced Concrete Aged Slab Specimen, Rawya Abdulsattar Abduljabbar

Theses and Dissertations

The deterioration of concrete bridge decks presents a maintenance challenge for most transportation agencies and bridge owners. This problem increases during the freeze-thaw cycle. De-icing salts can accelerate the deterioration process. Corrosion of steel reinforcement in reinforced concrete structures is considered a dominant factor causing premature deterioration, especially those structures located in a coastal environment. The resulting corrosion product produced has several times the volume of steel, resulting in cracking of the concrete cover if the corrosion is significant. In this study, a bridge deck specimen was subjected to an artificial environment to accelerate the corrosion process. Prior to this …

Ms. An (Meeting Students’ Academic Needs): A Socially Adaptive Robot Tutor For Student Engagement In Math Education, Karina Liles

Theses and Dissertations

This research presents a new, socially adaptive robot tutor, Ms. An (Meeting Students’ Academic Needs). The goal of this research was to use a decision tree model to develop a socially adaptive robot tutor that predicted and responded to student emotion and performance to actively engage students in mathematics education. The novelty of this multi-disciplinary project is the combination of the fields of HRI, AI, and education. In this study we 1) implemented a decision tree model to classify student emotion and performance for use in adaptive robot tutoring-an approach not applied to educational robotics; 2) presented an intuitive interface …

Photovoltaic Inverter Control To Sustain High Quality Of Service, Yan Chen

Theses and Dissertations

The increasing penetration of distributed solar photovoltaic (PV) generation presents both challenges and opportunities for distribution systems. The intermittent nature of solar irradiance may lead to power quality degradation. At the same time, PV inverters –if properly designed and operated– can be used to improve power quality. The goal of this dissertation is to develop power flow optimization methods for power distribution networks with high penetration of PV generation. The approaches proposed in this dissertation have been tested using the modified version of the IEEE 34-node distribution system and the IEEE 123-node distribution system, as well as the validated model …

Development Of A Supplier’S Delivery Time And Delivered Quality Performance Index And Assessment Of Alternative Decisions Regarding Underperforming Suppliers For The Aerospace Industry, Clint Saidy

Theses and Dissertations

This study investigates current practices of supplier’s delivery assessment so that a comprehensive index and a cost function model could be properly developed. Following a thorough literature review, a framework was created based on a penalty cost function that integrates both suppliers’ ability to deliver on time, as well as suppliers’ capability to deliver good quality. Afterward, suppliers could then be ranked and placed either in good standing, or transversely on probation. Underperforming suppliers face three potential outcomes based on current literature: (1) switching supplier, (2) increase collaboration, (3) maintaining the status quo. The decision vis-à-vis failing suppliers is based …

On The Security And Quality Of Wireless Communications In Outdoor Mobile Environment, Sharaf J. Malebary

Theses and Dissertations

The rapid advancement in wireless technology along with their low cost and ease of deployment have been attracting researchers academically and commercially. Researchers from private and public sectors are investing into enhancing the reliability, robustness, and security of radio frequency (RF) communications to accommodate the demand and enhance lifestyle. RF base communications -by nature- are slower and more exposed to attacks than a wired base (LAN). Deploying such networks in various cutting-edge mobile platforms (e.g. VANET, IoT, Autonomous robots) adds new challenges that impact the quality directly. Moreover, adopting such networks in public outdoor areas make them vulnerable to various …