Engineering Commons^™

Near Infrared Light Penetration In Human Tissue: An Analysis Of Tissue Structure And Heterogeneities, Paul Murray Koster

Master's Theses (2009 -)

Low level laser irradiation (LLLI) has been a controversial method of therapy due to a limited understanding of the underlying mechanisms that could cause the irradiation to provide its proposed benefits – increased blood flow, vasodilation, cell attachment, and wound healing. Near infrared (NIR) light appears able to function with nitrates and enzymes around the electric transport chain to allow biologically available nitric oxide to be released from hemoglobin and myoglobin. Nitric oxide has been shown to be a part of a mechanism that promotes blood flow, vasodilation, and wound healing.NIR penetration in biological tissue is not well described due …

Defining Aviation “Skills” To Ensure Effective, Safe, And Efficient Evaluations: A Qualitative Study, Jorge L. D. Albelo Ph.D., Haydee M. Cuevas, Marisa Aguiar, Christopher Piccone, Karlene Petitt, Raquel Villagomez

Publications

The present qualitative case study strives to define the term skill within aviation, drawing from the cognitive psychology, organizational psychology, and training literature as well as input from subject matter experts in the aviation industry. A review of the published literature revealed no consensus for defining what constitutes a skill. While some definitions follow a task-based approach, others emphasize more cognitively based representations. Moreover, a formal, commonly accepted definition of the term skill within the aviation domain is lacking. The researchers employed a qualitative case study methodology to extract true descriptions from the subject matter experts to bound and expand …

Vitrimerization Of Rigid Thermoset Polyurethane Foams: A Mechanochemical Method To Recycle And Reprocess Thermosets, Alireza Bandegi, Maya Montemayor, Ica Manas‐Zloczower

Faculty Scholarship

Polyurethane (PU) thermosets are extensively used in different applications and recycling the large amount of PU thermoset waste remains a universal challenge. Recycling the thermoset waste through vitrimerization is a feasible, cost-effective, and environmental-friendly approach. In this work, triazabicyclodecene (TBD) is used as organocatalyst in the vitrimerization process to recycle and reprocess thermoset rigid polyurethane foams. The results show that the permanent crosslinked structure of the PU thermoset foam is converted to a dynamic network upon vitrimerization. The vitrimerized network can rapidly relax the stress in 10 s at temperatures as low as 120°C. The topology rearrangement happens through the …

Studying Dynamic Pricing In Electrical Power Markets With Distributed Generation: Agent-Based Modeling And Reinforcement-Learning Approach, Gasser G. Ali, Islam H. El-Adaway, Charles Sims, J. Scott Holladay, Chien Fei Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Distributed generation (DG) refers to small-scale generation resources that are located at or near end-consumers, such as photovoltaic (PV) solar systems. DG systems have become increasingly popular in recent years owing to their economic efficiency, reliability, and sustainability. However, the increasing adoption of DG is creating new obstacles for system operators due to the uncertainty in forecasting future demand. One concern is the possibility of facing a utility death spiral as a feedback loop between, on the one hand, the increasing adoption of DG and increasing electricity rates to cover generation and transmission overheads with, on the other hand, reduced …

Push Them Forward: Challenges In Intergovernmental Organizations' Influence On Rural Broadband Infrastructure Expansion, Javier Valentín-Sívico, Casey I. Canfield, Ona Egbue

Engineering Management and Systems Engineering Faculty Research & Creative Works

Many rural US communities lack access to adequate broadband services. This paper draws on semi-structured interviews conducted in 2019 with 16 Regional Planning Commissions to uncover dynamics of how these intergovernmental organizations contribute to the deployment of broadband infrastructure in rural Missouri. The proposed framework integrates the decomposed Theory of Planned Behavior (TPB), the Theory of Reasoned Goal Pursuit, and Stakeholder Theory. Many participants reported a low level of involvement in broadband infrastructure initiatives even though supporting infrastructure development to promote economic growth is one of the Regional Planning Commissions' primary goals. Regional Planning Commissions are highly influenced by four …

Effect Of Cu Additions On Scale Structure And Descaling Efficiency Of Low C Steel Reheated In A Combustion Gas Atmosphere, Richard Osei, Simon Lekakh, Ronald J. O'Malley

Materials Science and Engineering Faculty Research & Creative Works

Modern EAF steelmaking employs scrap as its primary source of raw material. Different sources of scrap have varying levels of residuals, which can negatively influence product properties, performance, and surface quality. The presence of some residuals, such as Cu and Ni in controlled quantities, can also positively impact steel performance for some applications. It is also well known that interactions between residuals and alloying elements in steel can modify the structure of scale formed during slab reheating prior to hot rolling. These changes in the scale structure can influence scale removability. In this study, the effect of varying Cu concentrations …

Backscattering Analysis Utilizing Relaxed Hierarchical Equivalent Source Algorithm (Rhesa) For Scatterers In Vegetation Medium, Syabeela Syahali, Hong Tat Ewe, Gobi Vetharatnam, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

The backscattering cross section of cylindrical and elliptical disk-shaped scatterers was investigated in this study, utilising a new numerical solution method called the relaxed hierarchical equivalent source algorithm (RHESA). The results were compared with the backscattering cross section of similar cases, using analytical method validation from literature. The objective of this research was to look into the possibility of replacing analytical methods with the RHESA in volume scattering calculations, and integrating it into modelling the backscattering of layers of dense media for microwave remote sensing in vegetation; as RHESA provides the freedom to model any shape of scatterer, as opposed …

Predicting Defects In Laser Powder Bed Fusion Using In-Situ Thermal Imaging Data And Machine Learning, Sina Malakpour Estalaki, Cody S. Lough, Robert G. Landers, Edward C. Kinzel, Tengfei Luo

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Variation in the local thermal history during the Laser Powder Bed Fusion (LPBF) process in Additive Manufacturing (AM) can cause micropore defects, which add to the uncertainty of the mechanical properties (e.g., fatigue life, tensile strength) of the built materials. In-situ sensing has been proposed for monitoring the AM process to minimize defects, but successful minimization requires establishing a quantitative relationship between the sensing data and the porosity, which is particularly challenging with a large number of variables (e.g., laser speed, power, scan path, powder property). Physics-based modeling can simulate such an in-situ sensing-porosity relationship, but it is computationally costly. …

Validation And Verification Of The Wray-Agarwal Turbulence And Algebraic Transition Models For 2d External Airfoil Flows, Dean Ryan-Simmons

McKelvey School of Engineering Graduate Student Theses & Dissertations

Validation and verification benchmark test cases are employed in computational fluid dynamics (CFD) to determine the best practices in application of various CFD tools. These cases focus on the geometry modeling, mesh generation, numerical algorithms, and turbulence models to ensure consistent and accurate numerical simulation of physical phenomena. Assessing model accuracy is essential to identify areas of improvement in various turbulence models. Flow past several symmetric NACA airfoils, namely NACA 0012, NACA 0015 and NACA 0018 are standard test cases for validating and evaluating turbulence models’ accuracy since the experimental data is available for these airfoils. Available wind tunnel data …

Controlling Sars Related Illnesses In The Indoor Environment Using Hvac Ventilation Techniques, Natalie Mansson

Construction Management Theses

The COVID-19 pandemic has brought on a need for better ventilation systems due to the deadly spreading of the SARS-CoV and SARS-CoV-2 illness through the air. As the positivity rate increases sharply, this study is pertinent in the fight against the virus. The implementation of MERV filters and ventilation rates while also understanding respiratory droplets and how they move through the air is an important part of understanding airborne transmission. Much research has been done on MERV filtration and respiratory droplets and their traveling methods in the air, and this research aims to find the commonalities between prior research, and …

Modeling Of Temperature Dependence Of Λ-Graded Ingan Solar Cells For Both Strained And Relaxed Features, Mirsaeid Sarollahi, Mohammad Zamani-Alavijeh, Manal Abdullah Aldawsari, Rohith Allaparthi, Md Helal Uddin Maruf, Malak Refaei, Reem E. Alhelais, Yuriy I. Mazur, Morgan E. Ware

Electrical Engineering Faculty Publications and Presentations

The temperature dependence of Λ-graded InGaN solar cells is studied through simulation using nextnano software. Λ-Graded structures have been designed by increasing and then decreasing the indium composition in epitaxial InGaN layers. Due to polarization doping, layers of p-type and n-type doping arise without the need for impurity doping. Different individual structures are designed by varying the indium alloy profile from GaN to maximum indium concentrations, x_max , ranging from 20% to 90% pseudomorphically strained to a GaN substrate and from 20% to 100% for completely strain-relaxed materials and linearly decreases back to GaN. For In_xGa_{1-x …}

Design And Simulation Of Intelligent Control Algorithms For Bimanual Robot-Assisted Retinal Surgery Training System, Ali Ebrahimi

Link Foundation Modeling, Simulation and Training Fellowship Reports

Vitreoretinal surgery is among the most delicate surgical tasks in which physiological hand tremor may severely diminish surgeon performance and put the eye at high risk of injury. Unerring targeting accuracy is required to perform precise operations on micro-scale tissues of the eye. The objective of this project is to develop robotic platforms and intelligent control algorithms to provide a safe bilateral steady-hand eye manipulation for surgeons, which can potentially lead to autonomous surgical procedures. This will in tum enhance patient safety and surgical outcome which can be very beneficial to both patients and surgeons.

2022 (Fall) Ensi Informer Magazine, Morehead State University. Engineering Sciences Department

ENSI Informer Magazine Archive

The ENSI Informer Magazine published in the fall of 2022.

Novel Photonic Structures And Materials, Samar Fawzy

Theses and Dissertations

Plasmonic materials provide the ability to confine light in metallic structures in the nanometre scale, enabling their use in a wide range of applications, including metamaterials, energy conversion, biomedical applications, and transformation optics. Conventional plasmonic materials such as Silver and Gold suffer from two problems: very large negative real permittivity (𝜀1), preventing their integration with low-permittivity dielectrics, and large losses associated with conduction electrons such as: electron-electron scattering, electron-phonon scattering or scattering by crystal defects. Therefore, the search for alternative structures and materials that overcome these obstacles is indeed an essential task. Metamaterials, three dimensional (3D) periodic subwavelength metallic/dielectric structures, …

Supported Metal Bifunctional And Bimetallic Catalysts With Precisely Controlled Structures And Properties, Anhua Dong

Theses and Dissertations

In heterogenous catalysis, metallic nanomaterials play vital roles in numerous chemical processes. However, monofunctional catalysts are greatly impeded in their applications especially in the systems including tandem and/or sequential reaction steps. Besides, the catalytic performance can also be greatly influenced by the particle size, morphology, and geometry of the surface metal atoms.

The goal of this work is to synthesize bifunctional or bimetallic nanoparticles with high metal dispersion and homogenous alloys by rational synthetic strategies to facilitate the catalyst function. Strong electrostatic adsorption (SEA) is an effective and facile methodology to produce well dispersed and uniform nanoparticles. Metal-acid bifunctional catalysts …

Impacts Of Preferential Vaporization Of Multi-Component Liquid Fuels On Near-Limit Combustion Behaviors, Seungjae Lim

Theses and Dissertations

Combustion technologies used in energy conversion devices involve multi-phase and multi-component combustion behaviors associated with chemical kinetic characteristics coupled with spray dynamics. For reliable engine operation, the engine operation envelope is necessarily required to be determined by near-limit combustion behaviors such as flame flashback, lean blowout, ignition, and extinction, which are influenced by both fuel chemical and physical properties. Liquid fuels are composed of a wide range of molecular structures and weights, therefore exhibiting relatively large distillation temperature range. When fuel chemical properties change during fuel vaporization, preferential vaporization effects could play a considerable role in near-limit combustion behaviors. In …

Mimo Antenna Systems For Wireless Handheld Devices, Ahmed H. Abdelgawwad

Theses and Dissertations

Mobile communications have seen tremendous growths in the last decades in the form of smartphones, watches, wireless enabled Personal Digital Assistants (PDAs) and so on. The current and future wireless communication systems require high data-rate capabilities to support high speed needs of users in modern applications. Multiple-input multiple-output (MIMO) antenna systems have become the most promising candidate to support the increased data demand. Therefore, they have emerged as an integral part of the new 5G wireless standard. One key challenge regarding MIMO systems for the handheld is to be able to successfully accommodate multiple miniature platform integrated antennas within a …

Towards Modeling Of Induction Welding Of Thermoplastic Laminates With A Mixed Finite Element Boundary Element Approach, Florentius Johannes Van Zanten

Theses and Dissertations

There is an increased interest in induction welding of carbon fiber reinforced thermoplastic composite laminates within the aerospace industry. Currently, optimal manufacturing process parameters (e.g., current, power, and frequency settings, coil movement speed, etc.) are determined through an experimental trial-and-error approach. To reduce the need for an experimental approach that can determine the manufacturing process parameters, which would be expensive in both time and money, accurate and computationally efficient numerical tools are desired. This research is focused on improving the existing numerical tool, WelDone, in regard to its speed and accuracy.

WelDone utilizes a hybrid element formulation that combines traditional …

Investigating The Impact Of Endothelial Dysfunction And Aging On Vascular Remodeling Using Mouse Models, Liya Du

Theses and Dissertations

Endothelial dysfunction, characterized by a reduction in the bioavailability of nitric oxide (NO), is a major factor in the initiation and progression of atherosclerosis, an age-related chronic inflammatory process in the arterial wall and the leading cause of mortality and morbidity globally. A better understanding of alterations in vascular structure and function associated with endothelial dysfunction can facilitate the early detection of atherosclerosis and the development of potential pharmaceutical interventions. This study aims to clarify the impact of endothelial dysfunction in conjunction with aging on the microstructure of aortic extracellular matrix (ECM) and to elucidate the relationship between microstructural adaptation …

Molten Salt Thermal Properties Database – Thermochemical Development And Thermodynamic Assessment Of Various Molten Salt Systems, Johnathon Chandler Ard

Theses and Dissertations

The Molten Salt Thermal Properties Database – Thermochemical (MSTDB-TC) is a validated open-source database for thermochemical modeling of molten salt reactor (MSR) relevant fluoride and chloride salt systems. The database has been created and populated by leveraging available models from literature as well as completing novel system assessments. The development and contents of the MSTDB-TC v1.2 initial release are detailed along with various system assessments performed in the course of the work. The database utilizes a major strength of the CALPHAD thermodynamic modeling method. This is the ability to estimate higher-order system behavior by combining modeled lower-order systems, …

Digital Twins In Advanced Manufacturing To Enhance Manufacturing Efficiency, Max Kirkpatrick

Theses and Dissertations

Digital Twins of manufacturing systems are an emerging tool for improvement, optimization, and monitoring of physical manufacturing systems. The idea of representing physical systems with digital depictions has been prevalent since the early days of Computer Aided Design (CAD), but recently the concept of a Digital Twin has been expanded to encapsulate more than just a digital model of a design. Instead, the Digital Twin offers a unique, comprehensive, and real-time toolset for analysis and improvement of physical systems. These tools can be used to improve system efficiency, perform “what-if” analyses, virtually commission manufacturing equipment, analyze system performance in real …

Self-Sensing Smart Products In Smart Manufacturing Systems, Juergen Lenz, Eric Macdonald, Ramy Harik, Thorsten Wuest

Faculty Publications

We are surrounded by a growing number of products with embedded intelligence relying on sensors and internet access. These smart products, that already transform our lives, are also physical entities that need to be manufactured. Manufacturing today similarly relies on data and data-driven insights to improve quality, efficiency, and safety on the shopfloor. This paper discusses the vision to utilize the ability of smart products to sense and communicate already during their own manufacturing to enrich the smart manufacturing system’s data for better insights development and optimization. We furthermore, discuss the barriers and opportunities embedded in such a paradigm shift.

Zinc–Acetate–Amine Complexes As Precursors To Zno And The Effect Of The Amine On Nanoparticle Morphology, Size, And Photocatalytic Activity, Josh Eixenberger, David Estrada

Materials Science and Engineering Faculty Publications and Presentations

Zinc oxide is an environmentally friendly and readily synthesized semiconductor with many industrial applications. ZnO powders were prepared by alkali precipitation using different [Zn(acetate)₂(amine)_x] compounds to alter the particle size and aspect ratio. Slow precipitations from 95 °C solutions produced micron-scale particles with morphologies of hexagonal plates, rods, and needles, depending on the precursor used. Powders prepared at 65 °C with rapid precipitation yielded particles with minimal morphology differences, but particle size was dependent on the precursor used. The smallest particles were produced using precursors that yielded crystals with low aspect ratios during high-temperature synthesis. Particles …

Machine Learning In Aerodynamic Shape Optimization, Jichao Li, Xiaosong Du, Joaquim R.R.A. Martins

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Machine learning (ML) has been increasingly used to aid aerodynamic shape optimization (ASO), thanks to the availability of aerodynamic data and continued developments in deep learning. We review the applications of ML in ASO to date and provide a perspective on the state-of-the-art and future directions. We first introduce conventional ASO and current challenges. Next, we introduce ML fundamentals and detail ML algorithms that have been successful in ASO. Then, we review ML applications to ASO addressing three aspects: compact geometric design space, fast aerodynamic analysis, and efficient optimization architecture. In addition to providing a comprehensive summary of the research, …

Development Of An Integrated Salt Cartridge-Reverse Electrodialysis (Red) Device To Increase Electrolyte Concentrations To Biomedical Devices, Efecan Pakkaner, Jessica L. Orton, Caroline G. Campbell, Jamie A. Hestekin, Christa N. Hestekin

Chemical Engineering Faculty Publications and Presentations

Emerging technologies in nanotechnology and biomedical engineering have led to an increase in the use of implantable biomedical devices. These devices are currently battery powered which often means they must be surgically replaced during a patient’s lifetime. Therefore, there is an important need for a power source that could provide continuous, stable power over a prolonged time. Reverse electrodialysis (RED) based biopower cells have been previously used to generate continuous power from physiologically relevant fluids; however, the low salinity gradient that exists within the body limited the performance of the biopower cell. In this study, a miniaturized RED biopower cell …

Understanding Unsteady Corner Separation Within Wing-Body Junction Flows, Paul G. Winner

Doctoral Dissertations and Master's Theses

Wing-body junction flows, formed at the interface between a wing and fuselage surface, are a complex, coupled, three-dimensional, turbulent flow field. This thesis focused on the unsteady corner separation that develops at the trailing edge of this wing-body junction under certain conditions. A NACA 0015 wing mounted on a flat plate at an angle of attack of 13°was used as the model junction flow field. The wing had an aspect ratio of 8 with a linear washout twist of 15°. The Reynolds number based on the wing chord was Re_c = 4.5 × 10⁵. Time-dependent stereoscopic particle …

Nemesis Setup For Indirect Detection Of Wimps, W. H. Trzaska, Alexander Barzilov, T. Enqvist, K. Jedrzejczak, J. Joutsenvaara, M. Kasztelan, O. Kotavaara, P. Kuusiniemi, K. K. Loo, J. Orzechowski, J. Puputti, M. Slupecki, J. Szabelski, I. Usoskin, T. E. Ward

Mechanical Engineering Faculty Research

We summarize the evidence for DM-like anomalies in neutron multiplicity spectra collected underground with Pb targets by three independent experiments: NEMESIS (at 210 m.w.e.) NMDS (at 583 m.w.e.), and ZEPLIN-II (at 2850 m.w.e.). A new analysis shows small but persistent anomalies at high neutron multiplicities. Adjusted for differences in detection efficiencies, the positions of the anomalies are consistent between the three systems. Also, the intensities match when corrected for the acquisition time and estimated detection efficiency. While the three measurements are inconclusive when analyzed separately, together, they exclude a statistical fluke to better than one in a million. To prove …

Improving Char Combustion Models Using Micro-Ct, Automated Image Analysis, And Pore-Resolving Simulations, Dongyu Liang

Dissertations (1934 -)

Combustion of pulverized coal and biomass in furnaces and boilers involves millions of particles with a distribution of sizes and morphologies. Because char particles typically react under zone II conditions, in which pore-diffusion and heterogenous reaction both influence the rate of conversion, the morphology of the porous particles affects reactor-scale outputs. To understand the impacts of complex morphology, 3-D pore-resolving simulations employing real char geometries obtained from high-resolution X-ray microtomography are first used to study combustion of 150 coal char particles and 30 biomass char particles. Localized reactant penetration into the innermost regions of the particles is observed, facilitated by …

Contested Agile Combat Employment: A Site-Selection Methodology, Zachary T. Moer, Christopher M. Chini, Peter P. Feng, Steven J. Schuldt

Faculty Publications

Numerous factors complicate ACE site-selection decisions including peer-to-peer threats, complex geopolitics, and resource requirements. The proposed site-selection framework identifies existing airports best suited for strategic utilization to support combatant commands as they optimize agile combat employment infrastructure.

Reliable Mode Tracking For Gradient-Based Optimization With Dynamic Stability Constraints, Taylor Mcdonnell, Andrew Ning

Faculty Publications

In order to construct mode-specific flutter constraints for use in gradient-based multidisciplinary design optimization frameworks, mode tracking must be used to associate the current iteration's modes with the modes corresponding to each constraint function. Existing mode tracking methods, however, do not provide a method by which to ensure the accuracy of mode associations, making them unsuitable for use in situations where obtaining correct mode associations is critical. To remedy this issue, a new mode tracking method is presented which incorporates backtracking logic in order to maintain an arbitrarily high degree of confidence in mode correlations during gradient-based optimization and/or during …