Engineering Commons^™

Modeling The Torque Of Ferrite Nano-Particles As A Ferrofluid Suspended In Liquid To Determine The Electromagnetic Response To Angular Displacement, Jackson Tyler Brennecke

Masters Theses

Inertial sensing is an important part of engineering and technology, especially for determining spatial orientation. Most modern inertial sensing units rely on MicroElectroMechanical systems (MEMS) style gyroscopic sensors to determine angular acceleration. This research investigates a novel gyroscopic sensing technology that uses mechanical precision of magnetic nanoparticles, instead of MEMS, to determine inertial measurements. The only other study on this novel technology proposed a scalar set of equations for relating magnetic field and torque magnitude to the magnitude of angular displacement of the sensor. This research develops the theoretical model into a set of full vector equations, so that the …

A Framework To Support Automatic Certification For Self-Adaptive Systems, Ioannis Nearchou

Masters Theses

Presently, cyber-physical systems are increasingly being integrated into societies, from the economic sector to the nuclear energy sector. Cyber-physical systems are systems that combine physical, digital, human, and other components, which operate through physical means and software. When system errors occur, the consequences of malfunction could negatively impact human life. Academic studies have relied on the MAPE-K feedback loop model to develop various system components to satisfy the self-adaptive features, such that violation of the safety requirements can be minimized. Assurance of system requirement satisfaction is argued through an industrial standard form, called an assurance case, which is usually applied …

Changes In Neural Network Connectivity Of Normal Young Adults In Response To Power Wheelchair Trainer Using Eeg Coherence, Ruby Phung

Masters Theses

The ability to move and explore their surrounding environment plays a critical role in the development of cognitive function in children, especially during early childhood. The lack of independent and autonomous mobility is, therefore, a clear disadvantage for the overall development of children with multiple, severe disabilities. Limited number of studies have been conducted on the impact of power mobility device on this specific population. Previous exploratory and pilot studies showed promising results regarding quantifiable and consistent changes in the electroencephalogram (EEG) of children with multiple, severe disabilities when provided with power mobility training. This study aimed to further extend …

Analysis Of Center Of Pressure And Center Of Mass To Determine Patterns Of Postural Stability In Neurotypical Subjects, Natalie Tipton

Masters Theses

The body’s postural control mechanism is responsible for responding to perturbations of balance and keeping the body upright. One of the main ways that this is completed during quiet standing, where both feet are planted on the ground, is through center of pressure oscillations. In these oscillations, the center of pressure circles around the center of mass, constantly counteracting any lean that exists in the body. These oscillations can be recorded with floorembedded force plates and center of mass can be recorded with a motion capture system. In this research, these signals were recorded for stances with feet together and …

Prediction Of Isotropic Strain Hardening Material Properties Using Gradient Boosted Regression Tree Method And Hyperparameter Optimization, Darren R. Promer

Masters Theses

In this study a new technique is proposed for the determination of elastic-plastic stress-strain relations for isotropic materials using the force-displacement output from an instrumented indentation test, finite element simulation, and machine learning methods. This non-destructive testing methodology has promising potential for industry implementation. Applications to benefit from this method include the characterization of localized material properties on surface engineered components, and the post-manufacturing assessment of material properties for items such as additively manufactured metallic components and load-bearing welded joints.

Currently, the capability of the instrumented indentation test for determining material properties is limited to the elastic modulus and surface …

Flexible Capacitive Pressure Sensors And Triboelectric Energy Harvesters Using Laser-Assisted Patterning Process For Flexible Hybrid Electronic Applications, Valliammai Palaniappan

Masters Theses

This work focuses on the design, fabrication and characterization of novel flexible capacitive pressure sensors and triboelectric energy harvesters using laser-assisted patterning process for flexible hybrid electronic applications. Initially, the capacitive pressure sensor was developed by fabricating a set of polydimethylsiloxanes (PDMS) dielectric films with pyramid shaped micro-structures using a laser-assisted patterning process. The pressure sensor consists of two electrodes (top and bottom) that were fabricated by depositing silver (Ag) on flexible polyethylene terephthalate (PET) using additive screen-printing process. Finally, the pressure sensor was assembled by attaching the top and bottom Ag electrodes to the smooth side of pyramid shaped …

A Multiscale Thermomechanical Metal Additive Manufacturing Simulation And The Impact Of Geometry On Residual Stress And Distortion, Luis Fernando Silva Velasco

Masters Theses

Metal additive manufacturing is an enabling technology for the rapid prototyping and manufacturing of geometrically complex parts that would otherwise be difficult or impossible to manufacture. However, the manufacturing process can produce undesired residual stresses and distortions. The first part of the work describes the implementation of a multiscale, thermo-mechanical simulation modeling the metal powder bed fusion additive manufacturing process. NASA’s Micromechanics Analysis Code was is to incorporate the microscale effects of an evolving material porosity on the predicted macroscale residual fields. The simulation shows that modeling an evolving material porosity, as the material transitions from a metal powder to …

Numerical Performance Evaluation Of The Wooden Frame Structures With Adhesive Applied Connection Under Wind And Seismic Loading, Sharthak Bhandary

Masters Theses

The objective of the research is divided into two folds. The first objective is to study the state-of-the-art modeling method for the wooden frame construction, while the second objective is to evaluate the performance of a wooden frame structure with construction adhesives under hazardous loading conditions using the selected numerical modeling method. The numerical modeling tools were classified under academic and commercial categories based on the purpose of their development. Both academic and commercial tools were further classified based on model types of the structural systems (i.e., shear walls and three-dimensional (3D) buildings) and the applied loads (i.e., wind loading …

Optimized System For On-Route Charging Of Battery Electric Buses And High-Fidelity Modelling And Simulation Of In-Motion Wireless Power Transfer, Yogesh Bappasaheb Jagdale

Masters Theses

Electrifying cars, buses and trucks is an attractive means to reduce energy use and emissions, because it involves minimal restructuring of the transportation network. Transit buses drive fixed routes, minimizing driver range anxiety by properly sizing energy storage system but the major challenge to fully electrifying transit buses, is the amount of energy they consume in a day of driving. To enable a full day of operation, batteries need to be large, which is expensive and heavy. This work utilizes real-world transit bus data fed to a battery electric drive-train model to co-optimize charger locations, charger power levels, and vehicle …

Passive And Active Battery Balancing Methods Implemented On Second Use Lithium-Ion Batteries, Walter Bartek

Masters Theses

As the number of electric vehicles (EVs) increases, the number of used battery packs that require disposal increases; however, many of these packs still have useful capacity and can be repurposed. When using repurposed large lithium-ion battery packs, deviations between cells within a pack become problematic. These deviations result in a pack that is unbalanced, affecting performance and proving potentially hazardous when charging. Consequently, a battery management system (BMS) is needed. To provide safety, the BMS in this paper monitors and controls the operation of the battery pack. In addition, it controls the redistribution of charge between the cells within …

Effects Of Normobaric Hypoxia On Oculomotor Dynamics Of Aviator Students During A Simulated Flight Task, Carl Wesley Rider, Abby Mccarty, Anna Blackley, Austin Deshner, Josh Engberg, Kaela Ehrlich, Theodore Hu, Maja Jankovic, Moroni De Moors, Jared Hornsby, Mitchell Morrison, Brian Walsh

Masters Theses

Hypoxia occurs when the body's tissues are unable to obtain adequate oxygen supply and is the primary environmental factor present when pilots are exposed to increasing altitude levels. Hypoxia leads to impaired vision, cognition, and motor control function, which can negatively affect performance and become deadly if a pilot becomes incapacitated. Thus, objective identification of early-onset hypoxia is critical to increase the time of useful consciousness and prevent physiological episodes. Of the few studies utilizing eye-tracking, there is disagreement and mixed results concerning saccadic eye metrics as a means to measure and detect hypoxia. Therefore, the purpose of this study …

Fatigue Damage Characterization By Surface Roughness And Instrumented Micro – Hardness Measurements, Suraj Sanjay Nikam

Masters Theses

Fatigue is an essential consideration in the design of high performance, safety-critical structures, and components, as fatigue failure constitutes more than 70% of failures in dynamically loaded components. This research aims to shed light on the effect of surface roughness on the micro-hardness in metals through experimental techniques (Part 1), the correlation between the traditional fatigue testing and instrumented cyclic micro-hardness testing to determine the material properties modeled by Ramberg - Osgood relationship(Part 2), and the effect of the fatigue damage on micro-hardness and surface roughness (Part 3).

For this research, Al 7075 - T651 and Al 6061 - T651 …

Vehicle Performance Analysis Of An Autonomous Electric Shuttle Modified For Wheelchair Accessibility, Johan Fanas Rojas

Masters Theses

Autonomous vehicles (AV) have the potential to vastly improve independent, safe, and cost-effective mobility options for individuals with disabilities. However, accessibility considerations are often overlooked in the early stages of design, resulting in AVs that are inaccessible to people with disabilities. The needs of wheeled mobility device users can cause significant vehicle design changes due to requirements for stepless ingress/egress and increased space for onboard circulation and securement. Vehicles serving people with disabilities typically require costly aftermarket modifications for accessibility, which may have unforeseen impacts on vehicle performance and safety, particularly in the case of automated vehicles. In this research, …

Development Of A Finite Element Model Of The Stamping Process To Predict The Natural Frequencies Of Dimpled Beams, Varad Vasudeo Pendse

Masters Theses

Creating dimples on beams has been proven to be an effective way of altering their vibrational behavior. The objective of this research is to simulate the process of stamping using the finite element (FE) method to create a model of a dimpled beam. This dimple has non-uniform thickness, so it shows close agreement with its real-life counterpart.

ANSYS® Parametric Design Language (APDL) is used to build a three-dimensional (3-D) finite element model and simulate the process of stamping used to create the dimple. The structural simulation is validated by calculating the thickness and width of the deformed geometry of the …

Vehicle Velocity Prediction Using Artificial Neural Networks And Effect Of Real-World Signals On Prediction Window, Tushar Dnyaneshwar Gaikwad

Masters Theses

Prediction of vehicle velocity is essential since it can realize improvements in the fuel economy/energy efficiency, drivability, and safety. Many publications address velocity prediction problems, yet there is a need for the understanding effect of different signals for the prediction. There are numerous new sensor and signal technologies like vehicle-to-vehicle and vehicle-to-infrastructure communication that can be used to obtain comprehensive datasets. Several references considered deterministic and stochastic approaches that use the datasets as input to determine future operation predictions. These approaches include different traffic models and artificial neural networks such as Markov chain, nonlinear autoregressive model, Gaussian function, and recurrent …

Investigation Of Selective Laser Melting Fabricated Internal Cooling Channels, Colin Jack

Masters Theses

Channels where coolant is run to cool a system are common in injection mold tooling. Conventionally, these channels are machined into the mold. This has limited the design of mold cooling systems to the constraints of traditional machining processes, where straight circular channels machined from cast material are typical. The transfer of heat away from the part cavity into these cooling channels has a large effect on the cooling time of the injection mold cycle. In this investigation, laser powder bed fusion processes were used to create non-circular cooling channels. To compare cooling performance, elliptical and circular channels of equal …

Mission Architecture Analysis: Exploring Long-Period Comets From Multiple Staging Orbits, Gabriel Prescinotti Vivan

Masters Theses

Objects that have retained pieces of information about the early Solar System are key to our understanding of its formation and evolutionary history. However, the high delta-V required to reach these objects, such as long-period comets or interstellar objects, makes designing an intercept mission at the time of detection impractical. In this thesis, multiple heliocentric staging orbits are explored to serve as departure positions for future missions, prior to objects’ detections. By utilizing more than one staging orbit concurrently, the set of objects that are reachable is expanded, therefore increasing mission feasibility. Delta-V maps are generated and superimposed; two-impulse burn …

Comparison Of Optimal Energy Management Strategies Using Dynamic Programming, Model Predictive Control, And Constant Velocity Prediction, Amol Arvind Patil

Masters Theses

Due to the recent advancements in autonomous vehicle technology, future vehicle velocity predictions are becoming more robust which allows fuel economy (FE) improvements in hybrid electric vehicles through optimal energy management strategies (EMS). A real-world highway drive cycle (DC) and a controls-oriented 2017 Toyota Prius Prime model are used to study potential FE improvements. We proposed three important metrics for comparison: (1) perfect full drive cycle prediction using dynamic programming, (2) 10-second prediction horizon model predictive control (MPC), and (3) 10-second constant velocity prediction. These different velocity predictions are put into an optimal EMS derivation algorithm to derive optimal engine …

Cellulose Based Separator For High-Performance Lithium-Ion Batteries, Akshit Vaidya

Masters Theses

During the past two decades, lithium-ion batteries (LIBs) have gained great success in the field of portable devices, and currently, are penetrating to the market of vehicles. Compared to the fast development of LIBs, little efforts have been dedicated to the separator, which is one of the most important components of LIBs. Primarily, the lithium-ion battery separator has two functions, one is to prevent direct contact between the positive and negative electrodes, and the other is to provide a path for effective ionic transportation. Currently, the separator market of LIBs is dominated by polyolefin materials such as polypropylene, polyethylene, and …

Oxidized Phospholipid Regulation Of Chronic Inflammation In Endothelial Cells, Cameron Scott Brutsche

Masters Theses

Atherosclerosis, the primary cause of Coronary Heart Disease (CHD), has become one of the top causes of death in the world. As low-density lipoprotein (LDL) particles become trapped and oxidized inside arterial walls, the primary oxidation products of 1-palmitoyl-2-arachidonyl-sn-glycerol-3-phosphatidylcholine (PAPC) induce the binding of monocytes which can potentially lead to fatty plaque build ups. A fragment of one of these oxidation products, OxPAPC, has previously been studied and can act as standard for testing new phospholipids and how they affect protein expression levels. The central hypothesis of this study was that three newly studied classes of oxidized fatty …

Verification Of Effectiveness Of Spot-Heating Technique In Reducing Spread Of Weld Lines In Injection Molded Plastic Products, Shah Ashikul Abed Sakar

Masters Theses

In producing a plastic part in an injection molding machine many physical factors related to the machine, such as injection pressure, holding pressure, heater temperature, etc. play their roles in the overall quality of the produced part. There are many aspects of the quality of a plastic part, such as part strength, part dimensions, and part surface finish. If any of those aspects gets compromised, the part is considered to have some defects. Of all defects found in injection-molded plastic parts, one most common defect is the presence of weld lines.Weld lines are formed when the flow of the molten …

Numerical Investigation Of Leading-Edge Modifications Of A Naca Airfoil, Anisur Rahman Ikram

Masters Theses

A parametric investigation was carried out to understand the flow characteristics of tubercle airfoils and to determine the best approach and parameters for designing a tubercle airfoil. For this purpose, a straight edge base airfoil (NACA 4414) and several tubercle airfoils, by modifying the leading edge of the base airfoil, were created in SolidWorks and tested with Computational Fluid Dynamics (CFD) application software Star CCM+.

Alternative tubercle airfoil with elliptical bumps demonstrated superior post-stall performance when compared to their straight edge counterparts; their post-stall lift did not decrease drastically. However, their pre-stall lift coefficients were always lower than the base …

Evaluation Of Engineering Properties Of Soil In Al Butayn, Mudarraj Al Qassim And Turubah - Hail Saudi Arabia, Turki Essam A. Sehly

Masters Theses

"Fractures, sinkhole, building cracks, and ground subsidence have spread in many regions of the Kingdom of Saudi Arabia, some of which are related to seismic activity, others due to the presence of unstable soils (collapsing soils and Expansive soils) and others because of faults, while others result from drawing groundwater at great rates. The current study has several facts related to the formation of cracks and landslides, including:
1) A general study of geomorphology and geology of the study areas.
2) The causes affecting the formation of cracks and subsidence.
3) Detailed geomorphological and geological studies of the locations of …

Development Of Amine-Functionalized Mesoporous Alumina For Radioiodine Removal From Water, Mansour Mohammed Alsalbokh

Masters Theses

“Radioactive materials have spread due to careless disposal and nuclear disasters. Some radionuclides can exist in an aqueous media, like radioactive iodine. As a result, in this work amine-functionalized mesoporous alumina was developed to adsorb radioactive iodine from the liquid phase. Bismuth was incorporated, using a wet impregnation method, to test it as a possible silver replacement. Amine grafting was used to functionalize the surface of the mesoporous alumina. All materials prepared in this work were characterized by N₂ physisorption, FTIR and TGA to determine the textural properties, surface functionality, and amine loading. The synthesized materials were tested for …

Soil-Water-Energy Nexus Of Green Roofs, Katherine Ann Bartels

Masters Theses

"As the urban landscape continues to sprawl into previously undeveloped land to accommodate population growth, the need to design cities that effectively manage urban stormwater is imperative for a sustainable future. Green roofs use rain-harvesting techniques to reduce urban stormwater discharge while simultaneously providing traditional roof services as well as several ecosystem services. However, green roof media design varies greatly among commercial applications, and little guidance is available to engineers when selecting the media for prospective green roofs. Efforts to maximize stormwater retention and enhance urban heat island mitigation capabilities of green roofs while concurrently reducing nutrient loading were examined …

In-Situ X-Ray Imaging Of The Selective Laser Melting Process, Meelap M. Coday

Masters Theses

"Fusion-based metal additive manufacturing (AM) has garnered much interest in recent decades. Despite the popularity of fusion-based AM technologies such as selective laser melting (SLM), there are still fundamental questions and uncertainties that need to be addressed. In this work, we focus on the understanding of the undercooling in the SLM process and the uncertainties induced by the laser beam size, power, and scan speed. First, we report the estimation of undercooling in the SLM process from the solidification rate measured by in-situ high-speed synchrotron x-ray imaging, based on the dendrite growth velocity model. The undercooling changes as a function …

Shock Wave Propagation Behavior At Corners And Crosscuts In Five Small-Scale Tunnel Scenarios, David Pierre Doucet

Masters Theses

"Shock wave propagation in tunnels and other enclosed environments is substantially more complicated than in an open-air or even a surface detonation. There is still much to learn about how shock wave properties change as a wave propagates in an enclosed space, such as a mine tunnel, inside of a building, or city street. The geometry of the enclosure will have a large role in the propagation of the shock wave. This means that many different tunnel designs must be studied. This work tested five different designs using a modular small-scale model. The scenarios tested were Straight-line, Single Turn, Around …

Analysis Of Energy Economy In Muon Catalyzed Fusion Considering External X-Ray Reactivation, Nishant Raghav Pillai

Masters Theses

"An analysis of the energy economy of a theoretical muon-catalyzed nuclear fusion system has been made by invoking the use of point kinetic equations, Monte Carlo radiation transport simulations, and from a review of existing literature on muon-catalyzed fusion. An external X-ray reactivation source is proposed as a novel way to increase the number of fusions per muon and thereby overcome the so-called alpha sticking problem that has long been considered the primary impediment to breakeven muon-catalyzed fusion power. Free electron lasers, synchrotrons and Wakefield accelerators are discussed as possible bright X-ray photon sources. The addition of an intense external …

Design And Development Of Power Processing Units For Applications In Electrically-Propelled Satellite Systems, Kartikeya Jayadurga Prasad Veeramraju

Masters Theses

"Electrospray technology provides a way to ionize specialized liquids by applying high voltages across a sharp porous tip and a metallic mesh. This technology is widely used in the field of mass spectroscopy for generating ions for testing purposes. The dawn of nano-satellites posed new challenges in the miniaturization of many conventional satellite sub-systems. One significant challenge faced in such a process was the miniaturization of the propulsion system. Electrosprays have started to find their application in the field of Aerospace Engineering and now are formally known as Electrospray Thrusters. These thrusters provide high specific impulse and are attractive substitutes …

Serdes Channel Crosstalk Mitigation Methodology With Industrial Implementation Guidance, Junda Wang

Masters Theses

"With the increasing data rate of digital circuits, the differential crosstalk degrades the signal integrity performance in PCBs drastically. Usually, in the trace area, crosstalk can be isolated by stitching vias and adding shielding ground vias can also shield coupling in the ball gate array (BGA) and pin field area. The traditional way to mitigation crosstalk in the BGA and pin field area through adding more ground vias between signal pairs or increasing the spacing in between, it demonstrated us the efficiency on crosstalk cancellation efficiency but it also increases the size of products and it would be contradictory to …