Engineering Commons^™

Analysis And Optimization Of The Two-Phase Series Capacitor Buck Dc-Dc Converter, Salahaldein Ali Aboajila Ahmed

Graduate Theses and Dissertations

Current sharing schemes for conventional multi-phase converters are based on sensing each phase current to deliver the current information to their controllers. In conventional buck converters, this fact may require a preset current sharing ratio at the expense of efficiency, which eventually requires a larger sensing circuit to achieve the sensing accuracy of each phase. Introducing the concept of automatic current sharing is one of the solutions to tackle this issue. Automatic current sharing (Current Sharing Mechanism CSM) is an advanced way to distribute heat generation in multi-phase switching topologies at full load. A two-phase series capacitor buck converter (2-pscB) …

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

ENSI Informer Magazine Archive

The ENSI Informer Magazine published in the spring of 2022.

Development Of Porous Solid Acid Catalysts For Lignocellulose And Plastic Upcycling., Mohammad Shahinur Rahaman

Electronic Theses and Dissertations

My goal is to develop chemical processes for transforming waste to solve environmental problems and enhance sustainability. Environmental problems such as pollution and massive amounts of waste are the main drivers that stimulate my research ideas. I focused on creating novel, efficient catalytic processes for converting polymeric waste "feedstocks" into high-value chemicals by integrating my expertise in catalysis, materials science, and synthetic chemistry to develop porous solid catalytic materials. During my Ph.D., I focused on two polymeric feedstocks, lignocellulose, and discarded plastic.

Early in my Ph.D. journey, I focused on catalytic upcycling of lignocellulose. Lignocellulosic biomass is cost-effective, abundant, and …

Sanitary Ware Waste As A Source For A Valuable Biodiesel Catalyst, Mai H. Roushdy

Chemical Engineering

Biofuel is a type of fuel that is made from biomass using modern techniques rather than the relatively slow geological processes that lead to the development of fossil fuels. In Europe, biodiesel is the most widely used biofuel. The sanitary ware industry generates a lot of hazardous waste, such as waste gypsum molds. These molds are broken, pulverized, and reacted with NaCO3 to make CaCO3, which is then heated to produce CaO. The resulting CaO catalyzes the reaction between waste frying oil and methanol for biodiesel synthesis. To evaluate the effect of reaction parameters on the production of biodiesel, the …

Additive Manufacturing Of Sensors For Extreme Environments, Kiyo Tiffany Fujimoto

Boise State University Theses and Dissertations

Advanced manufacturing based direct-write technologies have emerged as the predominant enabler for the fabrication of active and passive sensors for use in harsh operating environments. The ability to directly write and integrate electronic components onto physical packaging can be achieved with additive manufacturing (AM) methods such as direct write technologies (DWT) which include aerosol jet printing (AJP), Ink Jet Printing (IJP), Plasma Jet Printing (PJP), and Micro-Dispense Printing (MDP). In this work, we investigate the use of these methods to accelerate, modernize, and enhance the functionality of sensors and instrumentation to achieve the goal of improving the safety and efficiency …

Design And Analysis Of Beam Steering Antennas For Next-Generation Wireless Communication, Shafaq Kausar

Boise State University Theses and Dissertations

Reconfigurable antennas have gained immense interest since the last few decades. Reconfigurable antennas can steer beams dynamically in response to the signal environment, they can also support multiple simultaneous beams. This research work aims to make considerable advancements in the design and analysis of low cost and low power beam steerable antennas. It focuses on the design and demonstration of several prototypes with advanced functionalities, such as passive (broadband, multi-beam, shapable beams) and active (electronically reconfigurable) antennas. The first part of this dissertation covers the design and development of passive metamaterial based multibeam antenna at 30 GHz. Designed antenna is …

Towards Improving The Properties And Furthering Acceptance Of Advanced Technology Nuclear Fuels, Jennifer K. Watkins

Boise State University Theses and Dissertations

To avoid detrimental environmental impacts from climate change, the world community needs to push for the use of clean energy technologies. Development of proposed advanced technology nuclear fuels supports efforts to ensure nuclear energy is included as a non-carbon emitting source of electricity generation. Advanced technology nuclear fuels, also referred to as accident tolerant fuels (ATFs), have received renewed interest for use in the current nuclear reactor fleet as well as in advanced reactor technologies due to their high uranium loading, desirable thermophysical properties, and performance under irradiation as compared to the benchmark oxide fuel. A limiting consideration for the …

Multiphase Layered Transition Metal Oxide Positive Electrodes For Sodium Ion Batteries, Eric Gabriel, Dewen Hou, Eungje Lee, Hui Xiong

Materials Science and Engineering Faculty Publications and Presentations

Multiphase layered transition metal oxides (LTMOs) for sodium ion battery (SIB) positive electrodes with phase interfaces across multiple length scales are a promising avenue toward practical, high-performance SIBs. Combinations of phases can complement each other's strengths and mitigate their weaknesses if their interfaces are carefully controlled. Intra- and interparticle phase interactions from nanoscale to macroscale must be carefully tuned to generate distinct effects on properties and performance. An informed design strategy must be paired with relevant synthesis techniques and complemented by spatially resolved characterization tools to manipulate different length scales and interfaces. This review examines the design, synthesis, and characterization …

2022 Spring Graduate Recognition Program, Propulsion Research Center, Robert Frederick

PRC Graduate Recognition

This program includes the graduate recognition program for spring 2022. Includes photographs, upcoming events, recent publications, and student profiles.

Interpolation And Extrapolation Of Optimally Fitted Kinematic Error Model For Five-Axis Machine Tools, Le Ma, Douglas A. Bristow, Robert G. Landers

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Machine tool geometric errors are frequently corrected by populating compensation tables that contain position-dependent offsets to each commanded axis position. While each offset can be determined by directly measuring the individual geometric error at that location, it is often more efficient to compute the compensation using a volumetric error model derived from measurements across the entire axis space. However, interpolation and extrapolation of measurements, once explicit in direct measurement methods, become implicit and obfuscated in the curve-fitting process of volumetric error methods. The drive to maximize model accuracy while minimizing measurement sets can lead to significant model errors in workspace …

Carbon Fiber Coil Spring Characterization And Manufacturing, Cooper Madrazo

UNLV Theses, Dissertations, Professional Papers, and Capstones

Helical coil springs are used in many mechanical design applications including industrial machines, devices, and vehicle suspension systems. It is desirable to minimize the weight of vehicle suspension systems as this can improve performance and handling. Most vehicle suspension coil springs are made from solid steel alloys or other metallic materials. Significant weight savings could be achieved if the metallic material were replaced by high performance fiber reinforced polymer composites. However, the coil spring geometry is a difficult manufacturing challenge for composite materials. The goal of this thesis was to investigate efficient and low-cost manufacturing methods to produce light-weight polymer …

A Wearable Electronic Monitoring Device For Low Pressure Garment Applications And Temperature Analysis For Prevention Of Ulceration And Infection, Francisco Mata Carlos

UNLV Theses, Dissertations, Professional Papers, and Capstones

The healing process of several medical conditions related to venous insufficiency and burn scar management can be improved by the proper application of pressure. Current practices for applying pressure to an extremity do not guarantee the consensus ideal interface pressures for such medical conditions. Applying a low pressure range (within 15 – 40 mm Hg) is challenging due to many factors, but especially because the actual pressure applied by a compression garment used on a patient is unknown. The proposed device, used to sense and display low pressure values, is described in detail throughout the chapters of this thesis.An electronic …

Effects Of Distributed Energy Resources On The Bulk Electric System, Stryder Loveday

UNLV Theses, Dissertations, Professional Papers, and Capstones

The traditional power grid was designed with a centralized resource distribution in mind, with a relatively small number of large power generation facilities supplying the vast majority of load. With recent efforts to further diversify the power grid as well as an increased interest in renewable energy sources, there has been an unprecedented amount of new DistributedEnergy Resources (DERs) added to the grid within the last decade. This often heavily influences the local demand where these resources are installed, often causing power to flow in ways not anticipated by the original design of the grid. This thesis reviews the potential …

Viability Of Energy And Fuel Sources For Interstellar Travel; Design And Feasibility Of The Construction Of Manned Interstellar Space Shuttles, Lukas Mittelman

UNLV Theses, Dissertations, Professional Papers, and Capstones

The importance of proving the viability of interstellar transport and addressing its potential hazards and pitfalls is immense. If we do not look toward the future and examine what could be waiting for us, we are doing our children, our children’s children, and so on, a disservice. Here we must attempt to lay the groundwork for our future scientists, engineers, and adventurers. Asking and answering questions like, which propulsion and energy systems must we incorporate to send us through the cosmos? Will we utilize technologies known today, such as fossil fuel rockets, fission or fusion rockets, and antimatter drives (pion …

Developing A Model-Based Approach To Forecast A Competitor's System, Christopher A. Del Vecchio

Theses and Dissertations

The purpose of this research is to develop a model-based approach to intelligence forecasting of a competitor’s system. This analysis currently uses a document-based practice to capture all knowledge of the forecast and its development. A framework of antithesis processes, or Anti-Processes, were derived from the systems engineering technical processes. This was then combined with analytical tradecraft from the field of competitive technical intelligence to build a SysML reference model, which was then applied to a small case study to enhance and refine the model. The Anti-Process framework and SysML reference model provide a rigorous, model-based approach to intelligence forecasts …

Contaminants Of Emerging Concern Behavior Within Water Renewal Facilities, Joshua C. Baker

Boise State University Theses and Dissertations

Emerging constituents (ECs), also called contaminants of emerging concern (CECs) are defined by the United States Environmental Protection Agency (U.S.EPA) as: “…pharmaceuticals and personal care products.” This also includes per- and polyfluoroalkyl substances (PFAS), which are used in waterproofing and non-stick cooking products. It is highly likely that regulatory limits will be placed on many ECs because they tend to accumulate in the environment and biological tissues with little to no transformation. ECs pose a threat to the ecological systems of our nation and the fundamental need for clean water by all life on earth. Clean water is essential for …

Poly Camtracker, Nickolas W. Ogilvie, Shawn W. Thai

Electrical Engineering

With the onset of the post-pandemic virtual classroom world, more and more classes are attempting hybrid-style instruction. To accomplish that, recordings of lectures are widely used, with presentation-sharing & audio recording capability. However, video recordings of lectures, with the ability to see the board, lab equipment, and the professor, are the optimal way to give the virtual students the best experience. Right now, technology is readily available for static camera recordings of lecture halls, but this may not suffice when it comes to larger lecture halls and lab demonstrations, where directed shots of equipment or the whiteboard are needed in …

Wave Interactions And Energy Cascade, Bailey Downing

Civil Engineering Undergraduate Honors Theses

Structural engineers design buildings and their components to withstand code-specified wind loads. The ASCE 7-16 manual sets the standards for calculating wind loads in the U.S. Depending on the velocity of wind, deflections may occur as wind passes through the building. The pressure reported from ASCE are based on wind tunnel measurements. The peak pressure from ASCE 7 is much less than what is measured from the field for a low-rise building. As an alternative economic tool, Computer modeling has been developed to help with this dilemma. Methods based on computational fluid dynamics (CFD) are used to calculate velocities and …

Evaluating The Effects Of Curing Methods On Bcsa Cement Concrete, Hannah Allen

Civil Engineering Undergraduate Honors Theses

BCSA cement is a type of cement that makes concrete set up much quicker than typical portland cement concrete. BCSA cement concrete also has a much higher compressive strength than that of portland cement concrete. This study was conducted to determine the effect of different curing conditions on the compressive strength of BCSA cement concrete.

Computational Speed Improvement Of The Well Optimized Linear Finder (Wolf) Transfer Function Estimation Methodology For Phase-Diverse Atmospheric Turbulence Compensation (Atc) Applications Using Pre-Calculated, Parallel Complex Exponential Phase Difference Chains, Erlin He

Theses and Dissertations

The Well-Optimized Linear Finder (WOLF) high-speed, phase-dominant, transfer function estimation method was developed by Professor William W. Arrasmith at Florida Institute of Technology. The novel, high-speed, transfer function estimation method is robust and can be applied to atmospheric turbulence compensation (ATC)/blind deconvolution optical imaging problems. The WOLF methodology uses a diversitybased approach with an adapted error metric to quickly remove effects of atmospheric turbulence and system noise effects present in an incoherent, optical imaging system. In this research, we improve performance of the WOLF algorithm by investigating the impact of applying parallel processing technology to pre-calculate an expanding set of …

Flight Test Evaluation Of Piper Seminole, Brian-Emmanuel Hopeton Walters

Theses and Dissertations

After taking FTE 5702 – Stability and Control class, taught by Dr.Kimberlin, I understood the concept of using an aircraft and then testing how it handles in the air. Almost all flight tests done on aircraft are done by the manufacturer. Some aircraft may have a lot of comprehensive information available, while others have little to no information. It can also be hard to find the specific data that a pilot or owner desires. These various tests allow a greater understanding of aircraft stability and performance available for analysis and relating. The aircraft I flew during FTE 5702 class was …

Nanomechanical Characterization Of Vascular Tissue Using Atomic Force Microscopy, Ana Isabel Delgado Peralta

Theses and Dissertations

Cardiovascular morphogenesis and pathophysiology have been associated with the mechanical properties of the vessel wall. In this work, nanomechanical properties of diseased arteries and control groups were quantified using the Atomic Force Microscopy (AFM). Both tip sizes of 20nm and 5µm were used for examining the local and global stiffness. First, we measured the stiffness as a potential index factor of the mice’s aortic aneurysm. Results have shown the stiffness of mice aortic aneurysm is 58.84 ± 30.26 kPa, which is significantly different (P < 0.05) from the stiffness of the control group of 4.70 ± 17.41 kPa. This was attributed to the degradation of elastin fibers and increment of collagen deposition in the vessel as observed in the histological analysis. The lesion heterogeneity was illustrated by the stiffness gradient from 40 kPa to 1.2 MPa within a 2µm2 region. We also examined the stiffness of the diabetic rat aorta as a potential biomarker for disease progression. Results have shown a significantly higher stiffness of 70.25 ± 14.10 kPa in diabetic rat aorta, compared with 54.19 ± 14.15 kPa in the control group. Lastly, we characterized the human aortic calcifications to fill the knowledge gap of scarce datasets for calcification stiffness. Results have demonstrated the calcification stiffness as 61.5 ± 35 kPa, which is significantly larger than the stiffness of the control group of 12.0 ± 4.4 kPa. The stiffness variation was attributed to the percentage of calcium deposits, observed from the histological analysis. These nanomechanical characterizations could be further used for a better understanding of arterial adaptation and to provide insights for effective vascular therapies.

Affordable Autonomous Vehicles For Deployment After Disastrous Events, Shannon Abolmaali

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

In disastrous events such as hurricanes and tornadoes, it has been observed that people get stranded and helpless without a feasible way to escape during those emergency situations. This became very evident during hurricanes, such as Katrina and Ida affecting millions of people seeking immediate rescue efforts. With the use of artificial intelligence and machine learning, we envision an autonomous vehicle, AV, which is able to find the most optimal and safest way to help those who are stranded to get them to a safe location. Electric vehicles, EV, and Autonomous Vehicles, AV, is becoming the future; minimizing the carbon …

Cellular Migration As A Function Of Magnetic Field Intervention, Amy Marie Vecheck

Theses and Dissertations

This work aims to assess cellular migration in three-dimensional structures as a function of Zeeman resonance. By using Zeeman resonance to initialize intersystem crossing of electrons, also known as the Radical Pair Mechanism, bioenergetics processes would be modulated. Processes such as oxygen consumption rate and extracellular acidification rate are indicative of cellular respiration and glycolysis and can be altered based on the orientation of the magnetic field applied: parallel and perpendicular, respectively. This study focused on the parallel orientation and looked to used Zeeman resonance to increase flavin adenosine dinucleotide, which results in preventing the breakdown of F-actin. Cellular viability …

Development And Characterization Of Low-Cost Out Of Autoclave Fiber Metal Structures, Codrington Edward Barzey Jr.

Theses and Dissertations

Fiber metal structures are structures formed by combining fiber reinforced plastics and metallic sheets. The most widely used fiber metal structure is GLARE®. GLARE® is solely used in the aerospace industry, due to its unmatched weight, crack propagation resistance, and inflated cost. Its inflated cost is attributed to the high-performance requirements of the industry that can only be achieved with high-cost materials and manufacturing processes. Unlike the aerospace industry, there are other industries that have far lower performance requirements but can still benefit by using fiber metal structures to reduce weight while improving performance. Traditionally, fiber metal structures are fabricated …

Precision Landing Of A Quadcopter Drone By Smartphone Video Guidance Sensor, Nicolas Bautista Holguin

Theses and Dissertations

This study describes the deployment, integration, and demonstration of the Smartphone Video Guidance Sensor (SVGS) as novel technology for autonomous 6 DOF proximity maneuvers and precision landing of a quadcopter drone. The proposed approach uses a vision-based photogrammetric position and attitude sensor (SVGS) to estimate the position of an illuminated landing target after video capture. A visual inertial odometry camera (VIO) is used to provide position estimates of the UAV in a ground coordinate system during flight on a GPS denied environment. The integration of both SVGS and VIO sensors enables the accurate update of position setpoints during landing maneuvers, …

The Grate Solution: Simplifying Viking Oven Packaging Processes, Megan Jansen

Honors Theses

The following report details work completed to improve the Viking Oven Corporation’s gas oven assembly line. The current state of the line hosts an unreliable system for packaging oven grates. Viking manufactures two types of gas ovens on the same line: open burner and closed burner. These different types require different prepackaged grates to be included in the final assembly area. Viking estimates that the wrong grates are sent to the customer ten percent of the time. The following report presents research, brainstorming, problem-solving techniques, and proposed solutions to the problem. The proposed solution would solve the problem at little …

Large Eddy Simulation Of The Wakes Of Three Urban Air Mobility Vehicles, Denis-Gabriel Caprace, Andrew Ning

Faculty Publications

Recent advances in urban air mobility have driven the development of many new VTOL concepts. These vehicles often feature original designs and futuristic shapes. Due to their novelty, the wake characteristics of such aircraft are unknown. However, large wake-induced velocities, should they exist, may be dangerous for any other vehicle evolving in their close proximity. Therefore, improved knowledge about the wakes of VTOL vehicles is needed to guarantee the safety of urban air mobility operations. In this work, we study the wake of three VTOL aircraft in cruise by means of large eddy simulation. We present a two-stage numerical procedure …

Comparison Of Cone Mosaic Metrics From Images Acquired With The Spectralis High Magnification Module And Adaptive Optics Scanning Light Ophthalmoscopy, Niamh Wynne, Heather Heitkotter, Erica N. Woertz, Robert F. Cooper, Joseph Carroll

Biomedical Engineering Faculty Research and Publications

Purpose: To compare cone mosaic metrics derived from adaptive optics scanning light ophthalmoscopy (AOSLO) images with those derived from Heidelberg Engineering SPECTRALIS High Magnification Module (HMM) images.

Methods: Participants with contiguous cone mosaics had HMM imaging performed at locations superior and temporal to the fovea. These images were registered and averaged offline and then aligned to split-detection AOSLO images; 200 × 200-µm regions of interest were extracted from both modalities. Cones were semi-automatically identified by two graders to provide estimates of cone density and spacing.

Results: Thirty participants with contiguous cone mosaics were imaged (10 males, 20 females; age range, …

Neural Correlates Of Multisensory Integration For Feedback Stabilization Of The Wrist, Aaron J. Suminski, Raymond C. Doudlah, Robert A. Scheidt

Biomedical Engineering Faculty Research and Publications

Robust control of action relies on the ability to perceive, integrate, and act on information from multiple sensory modalities including vision and proprioception. How does the brain combine sensory information to regulate ongoing mechanical interactions between the body and its physical environment? Some behavioral studies suggest that the rules governing multisensory integration for action may differ from the maximum likelihood estimation rules that appear to govern multisensory integration for many perceptual tasks. We used functional magnetic resonance (MR) imaging techniques, a MR-compatible robot, and a multisensory feedback control task to test that hypothesis by investigating how neural mechanisms involved in …