Mechanical Engineering Commons^™

Dewatering Ash – Progress Over The Last 5 Years, Greg M. Landry, Paul C. Schmall

World of Coal Ash Proceedings

No abstract provided.

Towards Development Of Sustainable Asphalt Pavement Using Off-Spec Fly Ash, Ahmed Faheem, Ahmed Abdalla, Konstantin Sobolev

World of Coal Ash Proceedings

No abstract provided.

Ccr Corrective Measures Assessment & Implementation – A Technical Roadmap And Smart Communication/Management Strategies, Steven F. Putrich, David Hagen

World of Coal Ash Proceedings

No abstract provided.

Upgrading The Properties Of Fly-Ash From Long-Term Storage, With Simultaneous Deagglomeration, Drying & Classification Using Atritor Technology, Andrew Rigg, Scott Coley, Paul Machacek

World of Coal Ash Proceedings

No abstract provided.

Lime Activated Coal Ash For Ccr Pond Closure Projects, Larry Gibson, Karen Slade

World of Coal Ash Proceedings

No abstract provided.

A Thermodynamic-Guided Approach To Recycle Off-Spec Fly Ash Into Lightweight Aggregate, Mohammad Balapour, Newell Moser, Edward J. Garboczi, Grace Hsuan

World of Coal Ash Proceedings

No abstract provided.

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.

Passivation Of Defects In Perovskite Materials For Improved Solar Cell Efficiency And Stability, Jinsong Huang, Xiaopeng Zheng

Department of Mechanical and Materials Engineering: Faculty Publications

Semiconductor devices , and methods of forming the same , include a cathode layer , an anode layer , and an active layer disposed between the cathode layer and the anode layer , wherein the active layer includes a perovskite layer . A passivation layer is disposed directly on a surface of the active layer between the cathode layer and the active layer , the passivation layer including a layer of material that passivates both cationic and anionic defects in the surface of the active layer .

Experimental Characterization And Manufacture Of Polymer Nanocomposite Dielectric Coatings For High-Temperature Superconductor Applications, Jacob Ryan Mahon

Theses and Dissertations

Increased implementation of high-temperature superconducting (HTS) power transmission has the potential to revolutionize the efficiency of electrical grids and help unlock a fully electric transportation infrastructure. Realizing the benefits of HTS systems has been impeded by a lack of available dielectric insulation materials that can 1) withstand the extreme cryogenic operating environment of superconductors and 2) demonstrate low temperature processing that is compatible with existing superconductor manufacturing methods. Solving this problem necessitates a high-performance dielectric material with multifunctional properties specifically suited for operation in HTS systems. A polyamide and silicon dioxide (PA/SiO2) nanocomposite material with exceptional thermal stability has been …

Design Improvement Of Transcatheter Aortic Valves For Aortic Stenosis Patients, Samantha K. Shoun, Ali N. Azadani

DU Undergraduate Research Journal Archive

Aortic valve disease is a common condition in patients above 60 years of age and is associated with significant morbidity and mortality. Aortic valve stenosis is characterized by the narrowing of the aortic valve, which can be quite debilitating. This disease is treated with transcatheter aortic valve replacement (TAVR), which is a rapidly expanding alternative to open-heart surgical aortic valve replacement (SAVR). Although TAVR is a less invasive than SAVR, long-term durability of the transcatheter aortic valves could be the Achilles heel of the procedure. Thus, the main objective of this research was to improve the design of transcatheter aortic …

Updates And Improvements To The Satellite Drag Coefficient Response Surface Modeling Toolkit, Phillip Logan Sheridan, Smriti Nandan Paul, Guillermo Avendaño-Franco, Piyush M. Mehta

Mechanical and Aerospace Engineering Faculty Research & Creative Works

For satellites in the Low Earth Orbit (LEO) region, the drag coefficient is a primary source of uncertainty for orbit determination and prediction. Researchers at the Los Alamos National Laboratory (LANL) have created the so-called Response Surface Modeling (RSM) toolkit to provide the community with a resource for simulating and modeling satellite drag coefficients for satellites with complex geometries (modeled using triangulated facets) in the free molecular flow (FMF) regime. The toolkit fits an interpolation surface using non-parametric Gaussian Process Regression (GPR) over drag coefficient data computed using the numerical Test Particle Monte Carlo (TPMC) method. The fitted response surface …

Thermal Management Using Liquid-Vapor Phase Change In Nanochannels, Sajag Poudel

Dissertations - ALL

Superior wettability of porous medium marks their potential to be used in the field of thermal management employing phase-change heat transfer. Comprehending the phenomena of wicking and liquid-vapor phase-change in micro/nano structured surfaces are key aspects towards advancing heat transfer solutions. In this work, fundamental understanding of droplet wicking, thin-film evaporation, and their subsequent application of heat-flux removal for cooling technology is first reported. The latter part of the dissertation is related to the disjoining pressure driven flow of nanoscale liquid film and liquid-vapor phase change in nano confinement. First, experimental and numerical investigation of droplet wicking in ∼728 nm …

Particle Formation And Thermal Radiation In Laminar Diffusion Flames With Applications To Energy And Materials, Phillip Irace

McKelvey School of Engineering Graduate Student Theses & Dissertations

Fossil fuels supply over 80% of the world’s primary energy, and if current policy and technology trends continue, global energy and energy-related carbon dioxide (CO2) emissions are predicted to increase for at least several decades owing to population and economic growth, leading to serious concerns regarding global warming. Natural gas releases less CO2 than other fossil fuels (e.g., coal and oil) and can help meet future CO2 emission targets. Natural gas combustion, however, has poor radiation heat transfer when compared to other fossil fuels owing to its low propensity for soot formation, making it difficult to use as a drop-in …

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 …

Design And Nonlinear Control Of A Haptic Glove For Virtual Palpation, Matthew Galla

Mechanical Engineering Research Theses and Dissertations

This dissertation presents the design, kinematic analysis, and nonlinear control of a Haptic Glove for medical elastographic imaging virtual palpation. Of the 13 degrees of freedom present in the index finger, middle finger, and thumb of the hand, the design fixes 4, constrains 2 and controls 6 with pneumatic air cylinder actuators, allowing uncontrolled, but measured motion in the remaining 1 degree of freedom. Nearly linear bijective transfer functions between the actuator positions and joint angles are found in closed form for all 6 actuated joints. A nonlinear, sliding-mode controller that allows each actuator to be controlled by a single …

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 …

Challenges And Signal Processing Of High Strain Rate Mechanical Testing, Barae Lamdini

Theses and Dissertations

Dynamic testing provides valuable insight into the behavior of materials undergoing fast deformation. During Split-Hopkinson Pressure Bar testing, stress waves are measured using strain gauges as voltage variations that are usually very small. Therefore, an amplifier is required to amplify the data and analyze it. One of the few available amplifiers designed for this purpose is provided by Vishay Micro-Measurements which limits the user’s options when it comes to research or industry. Among the challenges of implementing the Hopkinson technology in the industry are the size and cost of the amplifier. In this work, we propose a novel design of …

Lattice Boltzmann-Based Sharp-Interface Schemes For Conjugate Heat And Mass Transfer And Diffuse-Interface Schemes For Dendritic Growth Modeling, Nanqiao Wang

Theses and Dissertations

Analyses of heat and mass transfer between different materials and phases are essential in numerous fundamental scientific problems and practical engineering applications, such as thermal and chemical transport in porous media, design of heat exchangers, dendritic growth during solidification, and thermal/mechanical analysis of additive manufacturing processes. In the numerical simulation, interface treatment can be further divided into sharp interface schemes and diffuse interface schemes according to the morphological features of the interface. This work focuses on the following subjects through computational studies: (1) critical evaluation of the various sharp interface schemes in the literature for conjugate heat and mass transfer …

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 …

Design, Construction, And Characterization Of A Test Stand Used To Test Filter Media, Adam W. Parsons

Theses and Dissertations

Air filters are routinely used to remove various aerosols ranging from radioactive particles to airborne viruses. The overall performance of a filter may be simplified to consider only two main performance characteristics: 1) the efficiency at which particles are removed by the filter, and 2) the filter’s resistance to air flow. Per the DOE Nuclear Air Cleaning Handbook, HEPA filters require a minimum filter efficiency of 99.97% for particles 0.3 micrometers in diameter. Understanding how filters will perform with respect to time and mass loading is essential towards building more robust filters that operate more efficiently and safely. Analyzing the …