Digital Commons Network^™

Beneficial Use Of Fly Ash As A Sustainable Building Material, Randall Stremmel, Thomas Weyand

World of Coal Ash Proceedings

No abstract provided.

In-Situ Stabilization For Hydraulic Control At Ccr Sites, Paul R. Lear

World of Coal Ash Proceedings

No abstract provided.

Study To Evaluate Future Ash Beneficial Use, Corina Maria Aldea, Gil M. Haines, Matt Bishop

World of Coal Ash Proceedings

No abstract provided.

Coal Quality & Combustion Impacts On Ash Chemistry, Rod Hatt

World of Coal Ash Proceedings

No abstract provided.

Real Time Pore Pressure Monitoring Of Ash And Construction-Induced Responses: The State Of The Practice, Paul C. Schmall, Chris Hardin, Kenneth Campbell, Ryan Smith

World of Coal Ash Proceedings

No abstract provided.

Field And Laboratory Methods To Demonstrate Monitored Natural Attenuation For Coal Combustion Product Constituents In Groundwater, Jim Redwine, Masa Kanematsu, Kristi Mitchell, Dimitri Vlassopoulos

World of Coal Ash Proceedings

No abstract provided.

Addressing Public Fear With Facts—Tva Coal Ash Fact Sheets, Melissa Hedgecoth, Lisa Jn Bradley, Rock Vitale, Neil Carriker

World of Coal Ash Proceedings

No abstract provided.

Developing Single Use Deposits Of Coal Derived Fly Ash As A National Resource, Nigel Cooke

World of Coal Ash Proceedings

No abstract provided.

Six Years Of Service, Supply, And Success: Processing Harvested Ccr From Impoundments, William Fedorka, P.E.

World of Coal Ash Proceedings

No abstract provided.

Artificial Intelligence, Controls, And Sensor Fusion For Optimization And Modeling Of Space Missions And Particle Accelerators, Reza Pirayeshshirazinezhad

Mechanical Engineering ETDs

This PhD dissertation is devoted to developing artificial intelligence (AI) applications for space missions and particle accelerators considering constraints on the computational resources. The space mission studied in this research, the Virtual Telescope for X-ray Observations (VTXO), is the mission exploiting 2 6U-CubeSats operating in a precision formation. The goal of the VTXO project is to develop a space-based, X-ray imaging telescope with high angular resolution precision. VTXO space mission is designed and the mission is optimized to increase the performance of the mission. Trajectory optimization with AI, hybrid control, control algorithms, and high performance computing are all used to …

The Effect Of Surface Gas/Liquid Entrapment On Drag Reduction, Haosen Tan

Mechanical Engineering Research Theses and Dissertations

Economic globalization has made today’s world more closely linked, where transportation (e.g. shipping, pipeline) has played an important role. Approximately over 60% (in air), 80% (underwater), and 100% (in pipeline) propulsive power is used to overcome surface drag, so reducing surface drag will have a substantial impact economically and environmentally.

To develop a surface that has lower drag, the intuitive idea is to convert no-slip boundary conditions to slip or partial slip ones. To achieve that, the most promising approach is to replace the solid-liquid boundaries completely or partially with gas-liquid or liquid-liquid boundaries, because the shear stress is much …

Resistive Pulse Sensing Of Protein Unfolding And Transport In Solid-State Nanopores, Jugal Saharia

Mechanical Engineering Research Theses and Dissertations

Solid-state nanopore sensors have attracted considerable attraction as a tool for solution-based single-molecule studies and have been successfully utilized for characterization of biomolecules such as nucleic acids, proteins, glycans, viruses, etc. Among these, characterization of proteins has been more challenging due to their charge heterogeneity and the complex energy landscape associated with different protein conformations. Presented in this thesis is the fabrication of solid-state nanopores and their application for characterizing proteins and understanding their transport through nanopores. Fabrication of nanometer-sized pores in Si_xN_y membranes was achieved using the conventional controlled dielectric breakdown method as well as a …

Multi-Scale Modeling Of Dislocation Motion And Interaction: Theory, Plastic Properties, And Boundary Conditions, Abu Bakar Siddique

Mechanical Engineering ETDs

Dislocation theory is the fundamental tool for explaining plasticity in the material. The elastic field of a material is always influenced by the presence of dislocations and other defects independent of the loading configurations. Scientists and researchers have minimal success in solving plasticity problems analytically. And for this reason, the capturing of dislocation dynamics is highly dependent on numerical modeling, which is always a challenge for its inherent multi-scale nature. Current research investigates and develops self-consistent numerical models for different plasticity problems based on the distributed-dislocation technique and the collocation-point method. Numerical methods are developed for different boundary conditions in …

Assessment Of Mechanical Engineering Skills: A Synthesis Of Industry And Academic Graduate Level Curriculum Requirements, Francie Baker

Theses and Dissertations

Students who graduate with an advanced degree in mechanical engineering are a diverse group in their path to post-baccalaureate degree attainment. Some students choose to obtain their master’s or Ph.D. post bachelors, but before they enter the workplace. Others enter the workforce and return as full-time students or progress on their advanced degrees while maintaining part- or full-time employment. Current accreditation standards for undergraduate degree programs are part of a changing landscape of standards and professional requirements that have adapted and continue to adapt as programs prepare students to work in professional engineering fields. Advanced degrees do not have the …

Structural Sizing Of Post-Buckled Thermally Stressed Stiffened Panels, Walid Arsalane

Theses and Dissertations

Design of thermoelastic structures can be highly counterintuitive due to design-dependent loading and impact of geometric nonlinearity on the structural response. Thermal loading generates in-plane stresses in a restrained panel, but the presence of geometric nonlinearity creates an extension-bending coupling that results in considerable transverse displacement and variation in stiffness characteristics, and these affects are enhanced in post-bucking regimes. Herein a methodology for structural sizing of thermally stressed post-buckled stiffened panels is proposed and applied for optimization of the blade and hat stiffeners using a gradient-based optimizer. The stiffened panels are subjected to uniform thermal loading and optimized for minimum …

Experimental And Numerical Study Of Novel Coanda-Based Unmanned Aerial Vehicle, Zaid Feroz Siddiqi

Theses and Dissertations

To alleviate the thrust losses in radial direction experienced in conventional saucer-shaped Coanda Unmanned Aerial Vehicles (UAV), a rectangular, linear arrangement of the Coanda surface is adopted in the novel design. This arrangement minimizes the area change in the radial direction to recover such thrust losses. A prototype of the proposed UAV structure is 3D printed and assembled with a single 9-inch propeller. In addition, a custom-built dynamometer is designed specifically to measure propeller thrust under different loading conditions. Performance characteristics of the UAV are evaluated through static testing on the dynamometer which uses a load cell to measure the …

Student Understanding Of Kinematics: A Qualitative Assessment, Andrew Cashman, Tom O'Mahony

Publications

In engineering, kinematics is widely regarded as a fundamental topic with the literature agreeing that students possess a wide range in understanding of the topic. This study aims to take a second-order approach by understanding and exploring the qualitatively different ways in which students approach solving kinematics problems. Phenomenography was used to collect data through ten semi-structured interviews with early-stage mechanical engineering students. Following data analysis, four distinct categories of students’ approaches were identified; unstructured, framing the problem, strategic, and conceptual. It was found that these categories could be arranged in a hierarchy and were also supported by secondary epistemic …

Interaction Beyond Nearest Neighbor In Periodic Structures, Sudesh Pathak

Honors Theses

Periodic structures have been of particular interest to researchers and engineers due to their interesting vibrational characteristics leading to applications, namely acoustic filters, and waveguides. Many studies on the interaction of nearest neighbors have been performed. However, such studies are insufficient to understand the variation of band gaps and the maximum number of wave vectors for each frequency. The complex band structure obtained from the interaction beyond nearest neighbors can assist in the development of sophisticated acoustic technologies. This paper primarily emphasizes the study of such interactions with the development of mathematical models based on electrostatic forces, supported by the …

Electromechanical Fatigue Properties Of Dielectric Elastomer Stretch Sensors Under Orthopaedic Loading Conditions, Andrea Karen Persons

Theses and Dissertations

Fatigue testing of stretch sensors often focuses on high amplitude, low-cycle fatigue (LCF) behavior; however, when used for orthopaedic, athletic, or ergonomic assessments, stretch sensors are subjected to low amplitude, high-cycle fatigue (HCF) conditions. As an added layer of complexity, the fatigue testing of stretch sensors is not only focused on the life of the material comprising the sensor, but also on the reliability of the signal produced during the extension and relaxation of the sensor. Research into the development of a smart sock that can be used to measure the range of motion (ROM) of the ankle joint during …

Numerical Analysis Of Taylor Impact With Various Nose Shapes, Jean C. Santiago Padilla, Erik M. Chappell

ME 4233/6233 Fundamentals of FEA

The Taylor impact test is an experimental technique used to determine dynamic material response and to validate constitutive models used in numerical simulations. It generally consists of shooting a cylinder rod of a select material against a rigid target at different velocities. After impact, the plastic deformation of the cylinder is recorded and is directly compared to numerical predictions. Another application for Taylor impact was proposed by Li et al. (2021) where the nose shape of the cylinder is modified to create different loading environments that can test electronic equipment in penetration weapons. FEA models where designed in ABAQUS/Explicit to …

Development Of An Accelerated Life Testing Method For Reliability Assessment Of Wire Bonded Interconnects Subjected To Mechanical And Electromigratory Stresses, Whit Vinson

Graduate Theses and Dissertations

Power electronic advancement trends indicate that device power density will continue to increase as a result of increased power requirements and desired device form factor reduction in order to reduce weight and material costs and increase ease of integration into next-generation power systems. With these advancements come concerns regarding device reliability. The compounded effects of increased power density and form factor reduction in electrical conductors will yield amplified joule heating effects in addition to the already increasing device temperature profiles resulting from the incorporation of wide bandgap technology into power systems. Joule heating effects can lead to a variety of …

Enhancing Stability Of High-Nickel Cathodes For Lithium-Ion Batteries Through Additive Manufacturing Of Cathode Structure, Matthew Sullivan

Mechanical Engineering Undergraduate Honors Theses

Lithium-ion batteries (LIBs) are currently the best method to store electrical energy for use in portable electronics and electronic vehicles. New cathode materials for LIBs are consistently studied and researched, but few are as promising and attainable as nickel-rich transition metal oxides such as LiNi1-x-yMnxCoyO2 (NMC). NMC materials exist with many different mass ratios, but higher nickel content materials provide higher energy density. With this increase in capacity comes a sacrifice with cyclability, as high-nickel NMC variants are prone to structure collapse, transition metal dissolution, and cracks due to volume change. In this report, mechanical modification of the electrode by …

Autonomous Aerial Vehicles Distributed Control And Interactive Games, Yusuf Kartal

Mechanical and Aerospace Engineering Dissertations - Archive

As the number of quadrotors and other Unmanned Aerial Vehicles (UAVs) increases in industrial and urban areas, the development of reliable engineering methods to control their behavior as they interact with each other becomes of central interest in control research. With the increase in demand for UAVs to work together, several real-life challenges need to be addressed that include the implementation, test, and validation of the control algorithms in flight test experiments. On the one hand, the interests of UAVs may be in harmony to perform certain tasks such as transportation, surveillance and reconnaissance. On the other hand, the interests …

Calibration Procedure For Dic Strain Measurements During Vibration-Based Fatigue Testing, Benjamin D. Hill

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Vibration-based fatigue testing is fast and effective method for determining failure characteristics of a material. Often, a small electrical device called a strain gage is bonded to a rectangular plate specimen to measure the deformation of the plate during a test. However, these strain gages break before the plate does, so an alternative method would improve the results obtained from the test. As an alternative to strain gages, Digital Image Correlation (DIC) is a non-contacting, camera-based technique that measures the deformation of an object by comparing digital images taken before and after the object is deformed. During a vibration-based fatigue …

Material Synthesis And Additive Manufacturing Of Ceramics, Elsa Bramasco-Rivera

Open Access Theses & Dissertations

This research is divided into two main topics: vitrimer polymers and alumina ceramics. Additive manufacturing is an emerging technology. In this research, two main methods of additive manufacturing are used: material extrusion and vat photopolymerization. The hypothesis of self-healing and mechanochromism functionalities was tested through the synthesis of vitrimers, a novel material combining properties of both thermosets and thermoplastics. These vitrimers were 3D printed using material extrusion. Casted vitrimers showed stiffening effects after submergence in water. Lithography based ceramics have gained attention in recent years due to their wide range of applications. Alumina ceramics were additively manufactured using digital light …

Rheological Behavior Of Dspc-, Dbpc-, And Dppc-Oxygen Microbubbles And Their Effectiveness In Improving Survival In A Rat Model Of Lipopolysaccharide-Induced Acute Respiratory Distress Syndrome, Riaz Ur Rehman Mohammed

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Acute respiratory distress syndrome (ARDS) causes 75,000 deaths in the U.S., annually. It is characterized by hypoxemia and damage to the lung alveoli. ARDS Management strategies involve extracorporeal membrane oxygenation (ECMO) and mechanical ventilation, but none of these methods improve the mortality rates. Oxygen microbubbles (OMBs) consist of a lipid shell with an oxygen core and have potential to augment oxygenation to manage ARDS. Previous studies demonstrated significant improvements in systemic oxygenation and mortality upon administering OMBs.

We replicated an ARDS rat model by intratracheal administration of lipopolysaccharide at a 24 mg/kg dose. After inducing the disease in rats, the …

Design Of Path Correction For Improved Gait Rehabilitation, Zvonimir Pusnik

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Following a serious neurological injury or disease, such as a spinal cord injury or multiple sclerosis, many patients develop impaired gait (the ability to walk). There are many different pieces of equipment to help rehabilitate people with impaired gait, ranging from over ground walking with exoskeletons to treadmills with partial bodyweight support. Since the 1990s and 2000s, elliptical trainers have entered the rehabilitative field as a machine with low impact forces and gait-like motion. This led researchers at Madonna Rehabilitation Hospitals to collaborate with the University of Nebraska-Lincoln to create the Intelligently Controlled Assistive Rehabilitation Elliptical (ICARE).

While the ICARE …

Examining The Different Snap-Through Characteristics Of Bistable Cfrp Composite Laminates, Vishrut Deshpande

All Theses

Bistable carbon fiber composites, whose bistability arises from having asymmetric fiber layouts in different layers, have shown immense potential for use in shape morphing and adaptive structure applications. While many studies in this field focus on these composite laminates’ external shapes at the two stable states, their snap-through behavior of shifting from one stable shape to the other remains a critical aspect to be investigated in complete detail. Moreover, symmetric loading conditions have been extensively studied based on the classical lamination theory, but the asymmetric loading conditions received far less attention. Therefore, this study examines an asymmetric, localized point load …

Strain-Based Design Of Steel-Polymer-Steel Composite Pipes, Vul Thang

LSU New Orleans Theses and Dissertations

Many offshore single-wall pipelines and structural failures have occurred in the past. As a result, lives were lost, and billions of dollars were spent. In addition, natural disasters such as earthquake fault zones can cause a large volume of soil movement. This can easily damage single-wall pipelines or piles of fixed offshore platforms in the earthquake fault zone.

Currently, the single-wall pipelines are used for the offshore and onshore oil and gas industry. This research investigated the use of double-wall composite pipe steel-polymer-steel (SPS) in place of single-wall pipe to prevent such failures. The double-wall composite pipe has a larger …

Ambient Temperature Phase Change Launcher, Johnny Molloy

Senior Honors Projects

JOHNNY MOLLOY (Mechanical Engineering) Ambient Temperature Phase Change Launcher Sponsor: Bahram Nassersharif (Mechanical Engineering)

Deployment of payloads stored in watertight cylindrical bodies in underwater environmental conditions are of interest to the marine and naval community. The proposed work will investigate the possibility of using inert carbon dioxide gas compressed into its liquid state and stored under pressure to launch payloads by means of expansion from a cylindrical tube. To suit the needs of the Naval Undersea Warfare Center (NUWC), this launching system must fire from up to 14 ft underwater, have two degrees of freedom, and the payload must not …