Engineering Commons^™

A Framework And Model For Managing And Sustaining A Successful Cross Functional Project Operations Team In A Multi-Project Manufacturing Environment In The Aerospace And Defense Industry, Anisulrahman Nizam

Electronic Theses and Dissertations, 2020-2023

Project manufacturing is a production manufacturing mode that develops and produces large and complex systems that is supplemented by project management techniques for planning and execution. Project manufacturing is better understood by examining it along with three other key areas: manufacturing, project management, and team management. Critical success factors for each of these areas have been examined in the literature but have not been examined in a real world setting in the aerospace and defense industry. This research examines the association between perspectives of project teams and senior management on critical success factors along the four identified dimensions of success …

Wind Turbine Main Bearing Fatigue Prognosis With Physics-Informed Machine Learning, Yigit Yucesan

Electronic Theses and Dissertations, 2020-2023

Unexpected main bearing failure on a wind turbine causes unscheduled maintenance and increased operation costs (mainly due to crane, parts, labor, and production loss). Unfortunately, historical data indicates that failure can happen far earlier than the component designed lives (due to manufacturing problems, for example). For the legacy fleet, which composes the majority of the installed basis, fatigue has become a major issue. Although bearing fatigue can be expressed with physics-informed models, they often inherent large uncertainties due to operation and unknown lubricant degradation mechanism. Apart from the unknown physics of failure, additional uncertainties associated with the grease that surrounds …

Cooperative Target Tracking In Concentric Formations, Lili Ma

Publications and Research

This paper considers the problem of coordinating multiple unmanned aerial vehicles (UAVs) in a circular formation around a moving target. The main contribution is allowing for versatile formation patterns on the basis of the following components. Firstly, new uniform spacing control laws are proposed that spread the agents not necessarily over a full circle, but over a circular arc. Uniform spacing formation controllers are proposed, regulating either the separation distances or the separation angles between agents. Secondly, the use of virtual agents is proposed to allow for different radii in agents’ orbits. Thirdly, a hierarchical combination of formation patterns is …

Prediction Of Emg Activation Profiles From Gait Kinematics And Kinetics During Multiple Terrains, Erika V. Zabre-Gonzalez, Diego Amieva-Alvarado, Scott A. Beardsley

Biomedical Engineering Faculty Research and Publications

Continuous myoelectric prediction of intended limb dynamics has the ability to provide transparent control of a prosthesis by the user. However, the impact on these models of adding a human user into the control loop is less clear. Here, the ability of a User Response Model (URM) to continuously predict EMG activity from gait kinematics and kinetics collected during three mobility tasks (level-ground walking, stair ascent, and stair descent) was examined. Multiple-input, multiple-output NARX-based URMs were developed with two outputs (ankle plantarflexor and dorsiflexor) and variable inputs (ankle kinetics, and shank and/or ankle kinematics). Accuracy in predicting the tibialis anterior …

Developing An Institutional Arrangement For A Whole-Of-Government And Whole-Of-Community Approach To Regional Adaptation To Sea Level Rise: The Hampton Roads Pilot Project, Juita-Elena (Wie) Yusuf, J. Gail Nicula, Burton St. John Iii, Meagan M. Jordan, Michelle Covi, Carol Considine, Marina Saitgalina, Joshua Behr

School of Public Service Faculty Publications

Adaptation to sea level rise (SLR) requires coordination among local, state, and federal entities and collaboration across governments, nonprofits, businesses, and residents. This coordination and collaboration are reflected in institutional arrangements associated with a whole-of-government and whole-of-community approach to regional adaptation. This study analyzes the development of an interlocal agreement (ILA), the Hampton Roads Sea Level Rise Preparedness and Resilience Intergovernmental Planning Pilot Project (the Pilot Project), as an example of such an arrangement. This study assesses how factors throughout three phases of ILA development (initiation, implementation, and execution) influence outcomes and effectiveness. Drawing upon participant observation, document analysis, survey …

Electroporation Safety Factor Of 300 Nanosecond And 10 Millisecond Defibrillation In Langendorff-Perfused Rabbit Hearts, Johanna U. Neuber, Andrei G. Pakhomov, Christian W. Zemlin

Bioelectrics Publications

Aims

Recently, a new defibrillation modality using nanosecond pulses was shown to be effective at much lower energies than conventional 10 millisecond monophasic shocks in ex vivo experiments. Here we compare the safety factors of 300 nanosecond and 10 millisecond shocks to assess the safety of nanosecond defibrillation.

Methods and results

The safety factor, i.e. the ratio of median effective doses (ED50) for electroporative damage and defibrillation, was assessed for nanosecond and conventional (millisecond) defibrillation shocks in Langendorff-perfused New Zealand white rabbit hearts. In order to allow for multiple shock applications in a single heart, a pair of needle electrodes …

Cold Atmospheric-Pressure Plasma Caused Protein Damage In Methicillin-Resistant Staphylococcus Aureus Cells In Biofilms, Li Guo, Lu Yang, Yu Qi, Gulimire Niyazi, Lingling Huang, Lu Gou, Zifeng Wang, Lei Zhang, Dingxin Liu, Xiaohua Wang, Hailan Chen, Michael G. Kong

Bioelectrics Publications

Biofilms formed by multidrug-resistant bacteria are a major cause of hospital-acquired infections. Cold atmospheric-pressure plasma (CAP) is attractive for sterilization, especially to disrupt biofilms formed by multidrug-resistant bacteria. However, the underlying molecular mechanism is not clear. In this study, CAP effectively reduced the living cells in the biofilms formed by methicillin-resistant Staphylococcus aureus, and 6 min treatment with CAP reduced the S. aureus cells in biofilms by 3.5 log₁₀. The treatment with CAP caused the polymerization of SaFtsZ and SaClpP proteins in the S. aureus cells of the biofilms. In vitro analysis demonstrated that recombinant SaFtsZ lost …

Connexin Hemichannel Activation By S-Nitrosoglutathione Synergizes Strongly With Photodynamic Therapy Potentiating Anti-Tumor Bystander Killing, Chiara Nardin, Chiara Peres, Sabrina Putti, Tiziana Orsini, Claudia Colussi, Flavia Mazzarda, Marcello Raspa, Ferdinando Scavizzi, Anna Maria Salvatore, Francesco Chiani, Abraham Tettey-Matey, Yuanyuan Kuang, Guang Yang, Mauricio A. Retamal, Fabio Mammano

Bioelectrics Publications

In this study, we used B16-F10 cells grown in the dorsal skinfold chamber (DSC) preparation that allowed us to gain optical access to the processes triggered by photodynamic therapy (PDT). Partial irradiation of a photosensitized melanoma triggered cell death in non-irradiated tumor cells. Multiphoton intravital microscopy with genetically encoded fluorescence indicators revealed that bystander cell death was mediated by paracrine signaling due to adenosine triphosphate (ATP) release from connexin (Cx) hemichannels (HCs). Intercellular calcium (Ca²⁺) waves propagated from irradiated to bystander cells promoting intracellular Ca²⁺ transfer from the endoplasmic reticulum (ER) to mitochondria and rapid activation of …

Kinetics Of Photolysis And Photocatalytic Oxidation Of Ammonium Sulfite For Hydrogen Production, Moustafa A. Soliman, Maryam Zakaria

Chemical Engineering

The production of hydrogen via photocatalytic water splitting is one of the most promising technologies for obtaining chemical energy from direct solar energy while maintaining the least possible waste and pollutants. In this paper, we obtain the kinetic parameters necessary for the design of a photoreactor for photolysis and photocatalysis of ammonium sulfite solution. For the case of photolysis, we obtain the kinetics for the effect of changing the pH on the produced amount of hydrogen. For the case of photocatalysis, the intrinsic kinetic parameters of photocatalysis of water splitting reaction of ammonium sulfite and water in the presence of …

Preparation Of Co-Electrodeposited Pd-Au Nanocatalyst For Methanol Electro-Oxidation, Islam M. Al-Akraa, Ahmad M. Mohammad, Yaser M. Asal, Sayed S. Abd El Rehim

Chemical Engineering

No abstract provided.

Reliable And Efficient Cognitive Radio Communications Using Directional Antennas, Hassan Yazdani

Electronic Theses and Dissertations, 2020-2023

Cognitive Radio (CR) is a promising solution that enhances spectrum utilization by allowing an unlicensed or Secondary User (SU) to access licensed bands in a such way that its imposed interference on a license holder Primary User (PU) is limited, and hence fills the spectrum holes in time and/or frequency domains. Resource allocation, which involves scheduling of available time and transmit power, represents a crucial problem for the performance evaluation of CR systems. In this dissertation, we study the spectral efficiency maximization problem in an opportunistic CR system. Specifically, in the first part of the dissertation, we consider an opportunistic …

Evaluation Of Unconventional Signalized Intersections On Arterial Roads And A Proposition For A Novel Intersection Design, Ma'en Al-Omari

Electronic Theses and Dissertations, 2020-2023

Several unconventional intersection designs were proposed and implemented to enhance traffic safety and operation at intersections. The efficiency of these intersection designs was not sufficiently evaluated in the previous research because of the limited implementation of such designs. However, with the growing interest in the implementation of unconventional intersections by municipalities and transport agencies, it has become a need for a comprehensive evaluation of their safety and operational benefits. Therefore, this dissertation aims to evaluate the safety and operational aspects of unconventional intersection designs by employing different research approaches: crash analysis, microscopic simulation, and driving simulation. Firstly, this dissertation evaluated …

Atomically Thin Platinum-Based Dichalcogenide Materials For Multifunctional Photo-Sensitive Applications, Mashiyat Sumaiya Shawkat

Electronic Theses and Dissertations, 2020-2023

Two-dimensional (2D) transition metal dichalcogenides (TMDs) are a distinct class of atomically thin materials assembled by weak van der Waals bonding. They exhibit 2D layer number-dependent bandgap tunability promising exciting applications in electronics and optoelectronics. Among them, there is a surge of interest in Platinum-based dichalcogenides (e.g., PtSe2 and PtTe2). 2D PtSe2 has a theoretically predicted carrier mobility of > 1000 cm2/(Vs), at room temperature, which is higher than that of most 2D TMDs. Additionally, 2D PtSe2 exhibits a semiconducting to metallic transition with an increasing number of layers. 2D PtTe2 is highly metallic in its few- layer form and exhibits …

Econometric Frameworks For Energy Prediction, Naveen Chandra Iraganaboina

Electronic Theses and Dissertations, 2020-2023

Global warming and associated role of energy consumption across various sectors is a well-researched topic in recent years. Understanding current urban energy consumption patterns will allow us to understand how future energy consumption patterns will evolve. With electrification of vehicles and potentially altering culture of work from home, the energy usage at regional level would see a significant change in the future. The current PhD dissertation contributes to energy consumption analysis of a region by analyzing residential energy consumption, commercial energy consumption and transportation energy use by households. The aggregation of these energy consumption within a region contributes to the …

Fpga-Augmented Secure Crash-Consistent Non-Volatile Memory, Yu Zou

Electronic Theses and Dissertations, 2020-2023

Emerging byte-addressable Non-Volatile Memory (NVM) technology, although promising superior memory density and ultra-low energy consumption, poses unique challenges to achieving persistent data privacy and computing security, both of which are critically important to the embedded and IoT applications. Specifically, to successfully restore NVMs to their working states after unexpected system crashes or power failure, maintaining and recovering all the necessary security-related metadata can severely increase memory traffic, degrade runtime performance, exacerbate write endurance problem, and demand costly hardware changes to off-the-shelf processors. In this thesis, we summarize and expand upon two of our innovative works, ARES and HERMES, to design …

Data-Driven Analysis For Integrated Transmission And Distribution Systems With High Penetration Of Distributed Energy Resources, Inalvis Alvarez-Fernandez

Electronic Theses and Dissertations, 2020-2023

With the high penetration of inverter-based distributed energy resources (DERs), network situational awareness is a challenge for both transmission and distribution (T&D) system operators and planners. It is becoming increasingly important to equip transmission planners with the visibility of DER dynamic performance in distribution systems. Not having visibility of the disconnection of DERs with the occurrence of transmission events, could result in an erroneous view of the stability of bulk power system. The aggregated distributed energy resource (DER_A) model is able to model the aggregated dynamic response of inverter-based DERs in distribution circuits. The parameterization of DER_A model requires extensive …

The Effect Of Annealing Temperatures And Inert/Reactive Gasses On Optical Properties Of Cu2o And Cuo Thin Films, Radu Bunea

Electronic Theses and Dissertations, 2020-2023

The Cu₂O and CuO thin films were synthesized by using RF sputtering technique. Comparisons were made with films created by deposition at room temperature followed by thermal annealing between 1000C and 4000C and using different gases, oxygen (O₂) (oxidizing and reactive gas) and nitrogen (N₂) (inert gas), besides air. The thickness of the thin films were kept constant, around 2000 Å (Angstrom). In addition, the RF power and pressure deposition were kept constant, as well. The thin films were evaluated for a range of wavelengths between 200 nm and 400 nm (Ultra Violet spectrum), …

Analysis Of Three-Phase Rectifier Via Three Different Control Methods And Switch Power Loss Comparison, Yichao Wang

All Graduate Theses, Dissertations, and Other Capstone Projects

Traditional uncontrolled or phase-controlled rectifiers have the defects of lower power factor and nontrivial higher harmonics which causes the low efficiency of power, bad power quality, and so on. However, PWM rectifiers overcome the drawbacks mentioned above. They reduce the higher harmonics yielding better sinusoidal current on the grid side, achieve unity power factor and bidirectional power flow, and have better dynamic performance. So, it is favored more by academia and widely applied in high-performance power electronics devices. In this paper, the PWM rectifier is analyzed and a comparison of the switch loss on three-phase rectifier using three different control …

Novel New Modeling Procedure For Industrial Machinery With Nonlinear Connections, Steven Whitican

Dissertations, Master's Theses and Master's Reports

Given current timelines for rolling out production at volume, the ability to model portions of the production process is of paramount importance. To model production, high-fidelity models of production assets must be obtained. The production assets are comprised of linear and nonlinear structures. The linear structures are well understood and defined. Significant work has, and is, being done to understand the nonlinear components. This work focuses on developing and correlating a model of a nonlinear component. The component studied and modeled is a linear guide. Linear guides are bearings which facilitate translational motion of machine axes. An accurate model of …

Exploring The Impact Of Composite Material Fires And Associated Response Protocol On The Material Analysis During An Aircraft Accident Investigation, Flavio A. C. Mendonca, Natalie Zimmermann, Peng Hao Wang, Julius Keller

Publications

Metals, beginning in the 1930s, have been frequently used as the material of choice for aircraft construction (Hallion, 1978; Jakab, 1999). Common metals used in the aviation industry range from alloyed and heat-treated aluminum to titanium, magnesium, and superalloys, the latter used in specialized applications (Hallion, 1978; Mouritz, 2012). Nevertheless, a shift in aircraft construction – specifically in terms of the materials used – began in the 1970s, as composite materials were introduced into commercial aircraft (Mouritz, 2012). Among others, the increased use of composited materials was – and still is – propelled by the ability to manufacture comparative lightweight …

Real-Time Operation Of Microgrids, Salem Al-Agtash, Asma Alkhraibat, Mohamad Al Hashem, Nisrein Al-Mutlaq

Computer Science and Engineering

Microgrid (MG) systems effectively integrate a generation mix of solar, wind, and other renewable energy resources. The intermittent nature of renewable resources and the unpredictable weather conditions contribute largely to the unreliability of microgrid real-time operation. This paper investigates the behavior of microgrid for different intermittent scenarios of photovoltaic generation in real-time. Reactive power coordination control and load shedding mechanisms are used for reliable operation and are implemented using OPAL-RT simulator integrated with Matlab. In an islanded MG, load shedding can be an effective mechanism to maintain generation-load balance. The microgrid of the German Jordanian University (GJU) is used for …

Estimation Of Spacecraft Attitude Motion And Vibrational Modes Using Simultaneous Dual-Latitude Ground-Based Data, Zachary William Henry

Doctoral Dissertations and Master's Theses

Cutting-edge Space Situational Awareness (SSA) research calls for improved methods for rapidly characterizing resident space objects. In this thesis, this will take the form of speeding up convergence of spacecraft attitude estimates, and of a non-model-based approach to the detection of vibrational modes. Because attitude observability from photometric data is angle-based, dual-site simultaneous photometric observations of a resident space object are predicted to improve the convergence speed and steady-state error of spacecraft attitude state estimation from ground-based sensor data. Additionally, it is predicted that by adding polarimetric data to the measurements, the speed of convergence and steady-state error will be …

Bio-Inspired Materials For Electrochemical Sensors, Matthew Joseph Hummel

Electronic Theses and Dissertations

Electrochemical biosensors are a rapidly growing research area that has greatly improved its specificity, accuracy, and precision in the detection of biomolecules in contemporary literature and industry alike. Typically, these systems exist in a three-electrode conformation with a working electrode functioning as the anode, a counter electrode functioning as the cathode, and a reference electrode allowing for the control of potential in the system. The method by which these sensors work is through the sharing of electrons via redox reactions with the target molecule and the working electrode or modifications on its surface. By exploiting the function of biomaterials that …

Rees/Aaee Special Focus On Ethics: Introduction By Guest Editor, Shannon Chance, Shannon Chance

Articles

Today, more than ever, we see the significance of ethics in developing and sustaining the built, social, and natural environments around us. We also recognise the need to develop engineering students’ knowledge, skills, and values regarding engineering, innovation, design, production, and the like. Engineers’ actions can have intended as well as unintended consequences, and we as a community need to become more aware of the outcomes and implications of our work. In response to the many topics presented at the REES 2019, the REEN Board selected ethics as the focus for this special issue and joined with AAEE to publish …

Multidisciplinary And Multi-Objective Optimal Design Of A Cascade Control System For A Flexible Wing With Embedded Control Surfaces Having Actuator Dynamics, Christopher Stephen Greer

Theses, Dissertations and Capstones

A multidisciplinary and multi-objective optimization approach that integrates the design of the control surfaces’ sizes, active control systems, and estimator for an aircraft’s wing with three control surfaces is developed. Due to its attractive stability robustness properties, a control system based on the LQR (Linear Quadratic Regulator) is built for each control surface. The geometrical parameters of the control surfaces such as the span wise and chord lengths, the design details of the LQR penalty matrices, and the locations of the estimator poles are tuned by a widely used multi-objective optimization algorithm called NSGA-II (Non-dominated Sorting Genetic Algorithm). Four objectives …

Atomistic Continuum Simulations For Nano-Indentation And Compression Of Multi-Layer Graphene, Ashwini Nikumbh

Dissertations, Master's Theses and Master's Reports

Graphene has attracted a great share of research interest due to its extraordinary electrical, thermal, mechanical, and physical properties. Such spectacular properties of graphene open a wide range potential of applications in electronics, energy storage, composites, and biomedical fields. The mechanical properties of graphene can have a huge impact on its performance in graphene-based devices and thus it is important to study them. But the difficulties in experimental characterization and computational limitations to simulate large graphene sample consisting of billions of atoms makes it a challenging task. Thus, accurate and efficient simulation tools to predict the complex deformation of large …

Reverse Engineering Of Short Circuit Analyses, Anurag Nagpure

Dissertations, Master's Theses and Master's Reports

The electrical distribution system has evolved with embedded computer systems that can better manage the electrical fault that occurred around the feeders. Such random events can affect the reliability indices of overall systems. Computerized management system for distribution operation has been improving with the advanced sensing technologies. The general research question is here to articulate is the responsiveness for utility crew to pinpoint the exact location of a fault based on the SCADA fault indicators from pole-mounted feeder remote terminal units (FRTUs). This has been a tricky question because it relies on the information received from the sensors that can …

Predicting The Impacts Of Climate Change On The Great Lakes Water Levels Using A Fully Coupled 3d Regional Modeling System, Miraj Kayastha

Dissertations, Master's Theses and Master's Reports

The Great Lakes of North America are the largest surface freshwater system in the world and many ecosystems, industries, and coastal processes are sensitive to the changes in their water levels. The recent changes in the Great Lakes climate and water levels have particularly highlighted the importance of water level prediction. The water levels of the Great Lakes are primarily governed by the net basin supplies (NBS) of each lake which are the sum of over-lake precipitation and basin runoff minus lake evaporation. Recent studies have utilized Regional Climate Models (RCMs) with a fully coupled one-dimensional (1D) lake model to …

New Horizons For Processing And Utilizing Red Mud, M. Archambo

Dissertations, Master's Theses and Master's Reports

Red mud is an industrial slurry waste that is produced as a byproduct of the Bayer process for alumina. The waste is generated in large quantities, up to a ratio of 2:1 against the valued product alumina. Red mud exhibits many chemical and physical properties that categorize it as a hazardous material. Due to the addition of sodium hydroxide in processing, the pH is typically at values close to 13. Small particle size discourages separation from water for disposal, so drying red mud happens over many years.

The pH of red mud can be reduced with inexpensive reagents. Carbon dioxide …

Impact Of Hemodynamic Vortex Spatial And Temporal Characteristics On Analysis Of Intracranial Aneurysms, Kevin W. Sunderland

Dissertations, Master's Theses and Master's Reports

Subarachnoid hemorrhage is a potentially devastating pathological condition in which bleeding occurs into the space surrounding the brain. One of the prominent sources of subarachnoid hemorrhage are intracranial aneurysms (IA): degenerative, irregular expansions of area(s) of the cerebral vasculature. In the event of IA rupture, the resultant subarachnoid hemorrhage ends in patient mortality occurring in ~50% of cases, with survivors enduring significant neurological damage with physical or cognitive impairment. The seriousness of IA rupture drives a degree of clinical interest in understanding these conditions that promote both the development and possible rupture of the vascular malformations. Current metrics for the …