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Investigation Ionic Polymer Metal Composite Capacitors Through Fabrication, Experimentation, And Modeling, Liya S. Napollion

UNLV Theses, Dissertations, Professional Papers, and Capstones

The increasing demand for greater energy storage capacity alongside the need to minimize the size of various devices, such as hybrid electric vehicles, medical devices, and pulsed power systems—has highlighted the necessity for advanced polymer film capacitors with high energy density. While traditional batteries and electronic devices have generally sufficed for many applications, their inherent size limitations hinder their ability to deliver the high levels of peak power required for certain demanding applications. This shortfall highlights the critical ongoing challenge within the energy storage sector to improve technology and more effectively meet these growing power requirements. Flexible Ionic Polymer Metal …

Primary And Secondary Resonances Of Fringe Effect Electrostatically Actuated Mems Cantilever Resonators, Miguel Armando Martinez

Theses and Dissertations

The nonlinear dynamics of micro-electromechanical system (MEMS) cantilever resonators actuated by the fringe field at parametric and primary resonances are studied. Three models are used based on different descriptions of the system capacitance. In the fringe and capacitance models, the electrostatic force due to the parallel-plate capacitance is neglected due to a hole in the ground plate (removes overlapping area). The SolidWorks model is based on numerical capacitance simulations performed on SolidWorks using EMS. All three models that approximate the fringe field capacitance are compared with one another. The Method of Multiple Scales (MMS) and Reduced Order Model (ROM) up …

Vertically Aligned Nickel Cobalt Molybdenum Copper Oxide Nanotubes For High Performance Asymmetric Supercapacitors, Ricardo Herrera Aguirre

Open Access Theses & Dissertations

Designing materials having novel multi metal oxide electrodes with controlled structure and composition is a critical technological challenge for high performance supercapacitor applications. Quaternary metal oxides have attracted considerable attention in this field, where many methods have been used to improve their performance. In the present work, the nickel cobalt molybdenum copper oxide (NCMCuO2) has been synthesized using a hydrothermal method. The effect of different concentrations of Cu doping (0.5%,1.0% and 2.0%) on the NCM frame and structural and electrochemical properties of the quaternary metal oxide (NCMCuO2) are studied thoroughly. The XRD pattern of synthesized NCMCuO2 exhibited predominant (002) orientation …

Neural Operator And Physics-Informed Deep Learning Approaches For Inverse Design Of Composites And Manufacturing Processes, Minglei Lu

All Dissertations

In this dissertation, artificial intelligence (AI) models are designed and used to accelerate inverse design of composites and manufacturing processes. The critical bottlenecks in machine learning (ML) including data availability, data quality, model generalization and adaptation, interpretability, physical consistency, and the ’black box’ nature of models for the inverse design are addressed. And the proposed AI models are tested under different engineering scenarios. Firstly, a fast deep neural operator (DNO) structure was developed to significantly reduce training time. This model was tested in the context of additive manufacturing, a transformative industrial technology that allows for the creation of materials with …

Introducing The Second-Order Features Adjoint Sensitivity Analysis Methodology For Neural Ordinary Differential Equations—Ii: Illustrative Application To Heat And Energy Transfer In The Nordheim–Fuchs Phenomenological Model For Reactor Safety, Dan Gabriel Cacuci

Faculty Publications

This work presents an illustrative application of the newly developed “Second-Order Features Adjoint Sensitivity Analysis Methodology for Neural Ordinary Differential Equations (2nd-FASAM-NODE)” methodology to determine most efficiently the exact expressions of the first- and second-order sensitivities of NODE decoder responses to the neural net’s underlying parameters (weights and initial conditions). The application of the 2nd-FASAM-NODE methodology will be illustrated using the Nordheim–Fuchs phenomenological model for reactor safety, which describes a short-time self-limiting power transient in a nuclear reactor system having a negative temperature coefficient in which a large amount of reactivity is suddenly inserted. The representative model responses that will …

Finite-Time Control Strategies For Rendezvous And Proximity Operations, John Tamotsu Akagi

All Graduate Theses and Dissertations, Fall 2023 to Present

One common metric to use when designing a controller is the time that the system will take to reach the desired state. Unfortunately, many approaches to developing controllers only guarantee that the system will approach, but not exactly reach, the desired state. This can become a limitation in time-sensitive situations where rapid and complete convergence is necessary. One group of control methods, known as finite-time control, does guarantee both faster convergence and that the desired state will be reached, but often fails to define exactly what time that will occur, how much control will be used to get there, and …

Data-Driven Techno-Economic Analysis, Optimization, And Uncertainty Quantification Of Integrated Energy Systems In Deregulated Electricity Markets, Jacob A. Bryan

All Graduate Theses and Dissertations, Fall 2023 to Present

Electricity is a ubiquitous energy source in daily life, powering everything from stovetops and cellphones to vehicles and industrial processes. While wind and solar power have become increasingly common sources of electricity, the majority of electricity is still produced by burning fossil fuels, releasing greenhouse gases and propelling climate change. Wind and solar power cannot economically replace these fossil fuel energy sources on their own because they do not produce consistent power; the wind must be blowing, and the sun must be shining for them to make electricity. Nuclear power is a reliable source of energy that does not generate …

Heterogeneous Collaborative Robotics: Multi-Robot Navigation In Dynamic Environments, Tyler Nicholas Raettig

Theses and Dissertations

Abstract: The challenges of multi-robot navigation in dynamic environments, focusing on uncertainties in obstacle complexities, partial observation, and the transition of policies from simulations to the real world. The proposed approach utilizes a deep reinforcement learning (DRL) framework enabling a Light Detection and Ranging (LiDAR)-equipped robot to communicate with a camera-equipped robot to achieve optimal paths despite their different sensors. The key contributions include the development of a cooperative architecture for information exchange between robots, a DRL-based framework for learning navigation policies, and a training mechanism based on dynamic randomization for enhanced real-world adaptability. Experimental validation using Gazebo simulations demonstrates …

Improving Robustness Of Learning-Based Approaches In Autonomous Systems And Engineering Education, Godwyll Aikins

Theses and Dissertations

This dissertation advances the development of robust learning-based approaches across two complementary domains: engineering education and autonomous systems. Through four studies, this research addresses critical challenges in preparing data-proficient engineers and developing reliable autonomous systems that can operate under uncertainty and incomplete information. The engineering education study examines how mechanical and aerospace engineering undergraduates conceptualize and develop data proficiency skills essential for modern engineering practice. Through interviews with 27 students, the research employs the How People Learn framework to analyze student perspectives on information literacy, data interpretation, and computational thinking. The findings inform pedagogical strategies for developing data proficiency in …

End-To-End Learning For A Low-Cost Robotics Arm, Abhishek Chothani

Theses and Dissertations

Robotic manipulation is a cornerstone of automation, with the ultimate goal of developing versatile systems capable of executing a wide range of real-world tasks autonomously. Traditional robotics approaches, while reliable and widely adopted in industrial settings, often struggle with adaptability, perception, and dynamic task execution. This thesis explores the evolution from classical robotics techniques to modern learning-based approaches, leveraging advancements in artificial intelligence to overcome these limitations.

Initially, the thesis presents a pick-and-place pipeline built using the Drake robotics framework and the KUKA iiwa robotic arm. This system employs a pseudoinverse controller for inverse kinematics to perform structured tasks like …

Influence Of Hygrothermal Conditions Of The Bistability Of Asymmetric Carbon Fiber Laminate Composites, Celia Hill

All Theses

Carbon fiber-reinforced polymer (CFRP) laminates have widespread use in many industries because of their exceptional strength-to-weight ratio. Carbon fiber laminates following an asymmetric layup orientation can exhibit bistability meaning the laminate can exist at two stable geometric configurations. The morphing characteristics of bistable CRFP has a growing level of interest because of its potential in various applications including space aircraft structures for easy repair, automotive structures for energy dissipation and ergonomics, robotics for flexible motion and energy harvesting. Existing research shows that both moisture and temperature affect the material properties and behavior of CFRP laminates, however, the influence of moisture …

Control Of X-Delta Arm And Self-Leveling Robot Systems For Uav Applications, Prathibha Sobha

UNLV Theses, Dissertations, Professional Papers, and Capstones

The water droplet penetration test (WDPT) is an environmental assessment method for analyzing soil properties by measuring the penetration of water droplets into soil. This test provides insights into soil moisture retention and resilience, especially valuable in fire-prone or arid regions where soil recovery and erosion control are essential. Although this project does not conduct an actual WDPT, it investigates two key robotic systems designed to support such applications: an X-delta robot arm, which simulates precise droplet delivery patterns, and a self-leveling platform that ensures stability on uneven terrain, where the X-delta robot is mounted. Together, these systems examine the …

Mechanically Cost-Effective Approach For Bipedal Walking In Robots Using Instantaneous Collision Angle, Smit R. Patel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Humans, as bipedal locomotors, are effective at reducing the mechanical cost of transport (CoTmech) by adopting movement strategies and gaits that minimize energy expenditure for a given distance. By using different gaits at different speeds, leveraging their long spring-like tendons and muscle elasticity which store and release energy during movement, humans reduce the mechanical effort required for locomotion. Current locomotion solutions offered in bipedal robots, based on legacy walking and running gait models, are not great at energy efficiency unless walking at very low speeds. Additionally, the control system of robots, designed to ensure stability and adaptability, requires substantial resources, …

The Effect Of Mixing Time And Rotation Speed On The Consistency Of Dough Viscosity In A Horizontal Mixer, Muhammad Akhlis Rizza, Ekky Yovianto Dharsono, Anggit Murdani, Ratna Monasari, Radhi Nurvian Amrullah, Supa Kusuma Aji, Dian Noorvy Khaerudin

Journal of Mechanical Engineering Science and Technology (JMEST)

Cassava must go through several manufacturing processes before it becomes chips on the market, including the process of stirring the dough. The stirring process is an important stage in various food industries. In the stirring process, the viscosity change in the dough is influenced by various factors, including the stirring process time and speed in stirring. Research on dough viscosity is important because it is directly related to the quality of the final product. The purpose of this study is to provide recommendations to users, both in the context of using horizontal mixers and the process of making similar products. …

Structural Simulation Of Wheelchair Ramp Using Finite Element Method, Bhre Wangsa Lenggana, Agung Nugroho, Ubaidillah Ubaidillah

Journal of Mechanical Engineering Science and Technology (JMEST)

Wheelchairs are essential mobility aids for people with disabilities, but they are often limited to flat surfaces and cannot overcome height differences. Portable ramps are an effective solution to overcome this limitation. This research aims to simulate and analyze the structure of a portable ramp for wheelchairs. Simulations were conducted using finite element method analysis software to assess the portable ramp's von Mises stress, deformation, and safety factor in various loading positions. Finite element method (FEM) analysis software was utilized to evaluate key mechanical properties, including von Mises stress, deformation, and safety factor, under different loading conditions and positions. The …

Study On Thermal-Fluid-Solid Coupling Characteristics For Helicopter Intermediate Spiral Bevel Gear Reducer, Dongping Sheng, Jie Yang, Chun Su

Journal of Mechanical Engineering Science and Technology (JMEST)

In the helicopter transmission system, the intermediate reducer is particularly special. It uses bevel gear pairs to change the transmission direction and to transfer the rotational speed effectively. Therefore, an in-depth study of the spiral gear pair is crucial to improve the overall performance of the helicopter rotor system. This study focuses on the study of the thermal-fluid-solid coupling characteristics and one-way steady-state thermal finite element analysis are conducted based on volume of fluid multiphase flow simulation theory to provide strong support for the design and optimization of the helicopter intermediate reducer. Several conclusions could be obtained. Firstly, it could …

Characterization Of Hydroxyapatite Derived From Scallop Shell Waste Synthesized By Sonochemical Method With Different Temperature Calcination, Diki Dwi Pramono, Poppy Puspitasari, Aminnudin Aminnudin, Jeefferie Abd Razak

Journal of Mechanical Engineering Science and Technology (JMEST)

One common bio-ceramic material used in the biomedical industry is hydroxyapatite. Because of its crystallographic and molecular resemblance to the hard tissues of the human body, hydroxyapatite is thought to form. Scallop shells are one natural source of hydroxyapatite, which is high in calcium. This study examines how the calcination temperature affects the characteristics of hydroxyapatite made from leftover scallop shell. Hydroxyapatite was synthesized via the sonochemical method, with calcination conducted at temperatures of 900°C, 1000°C, and 1100°C. The hydroxyapatite that was prepared was assessed using Xray diffraction (XRD) to determine the phase and crystallite size, Scanning Electron Microscopy (SEM) …

Collaborative Robotics: Application Of Delphi Method, Jean-Marc Salotti, Ephraim Suhir

Mechanical and Materials Engineering Faculty Publications and Presentations

In the domain of collaborative robotics, it is often needed to make complex multiparametric choices or assessments that combine heterogeneous criteria, such as task performance, reliability, safety, and ergonomics. The Delphi method, a process of arriving at group consensus by providing experts with rounds of questionnaires, as well as the group response before each subsequent round, can be applied to solve this type of problems. The following Delphi method efforts are addressed in our analysis with application to finding appropriate criteria and their relative weights for the evaluation of the teleoperation task of a robotic platform: (1) Contribution of experts; …

Characterizing West Florida Shelf Reef Fish Communities Using A Scientific Echosounder, Edmund A. Hughes

USF Tampa Graduate Theses and Dissertations

The advancement and application of non-invasive fisheries survey technologies, such as the scientific echosounder, have significantly enhanced our understanding of fish populations and their habitats, more recently in regions where traditional sampling methods are limited, such as complex reef habitats. This research, conducted as part of the Continental Shelf Characterization, Assessment, and Mapping Project (C-SCAMP) on the West Florida Shelf, leverages acoustic and visual technologies to investigate the distribution of fish densities, fish target strength and length relationships, and the relationship between seafloor topography and fish biomass distribution.

The first study compared reef fish densities estimated from near-concurrent acoustic (Simrad …

Autonomous Driving Trajectory Prediction, Carlos Funes

Undergraduate Research Symposium Lightning Talks

Autonomous driving is undoubtedly one of the world's most revolutionary technologies, opening the door to a more secure traffic environment. This innovation has led to vehicles being able to drive by themselves without the necessity of a person behind the wheel, as well as cruise control, lane-keeping assist, and automatic emergency braking. Unfortunately, there is still plenty of work before autonomous driving becomes more popular among drivers. While at UNLV as an undergraduate student/research assistant, one of my goals is to learn how these technologies work to bring ideas into the automotive industry by refining solutions to problems within these …

Mitigation Of The Environmental Impacts Of Lithium Extraction And Lithium Battery Manufacturing, Dominick R. Strollo

Sustainability Conference

Lithium extraction and the production methods utilized for lithium-ion batteries can have a large impact on the areas directly surrounding them, and if not mitigated properly, the rest of the world as well. For these batteries to be produced, lithium must be mined and refined from sources all around the world. The main concern of lithium mines is their impact on the water cycle and the surrounding water tables due to the heavy metals involved in the process and the sheer amount of water required. Production of the batteries themselves using the lithium slurry is far less impactful on the …

Computational Design Of Complex Concentrated Alloys, Hamid Sharifi

Doctoral Dissertations

A high-throughput parameterization of modified embedded atom model (MEAM) interatomic potentials for combinations of Cu, Ti, Ni, Cr, Co, Al, Fe, and Mn was carried out using a genetic algorithm. Unary systems were parameterized based on DFT calculations and experimental results. MEAM potentials for 28 binary and 56 ternary combinations of the elements were parameterized to DFT results that were carried out with semi-automated frameworks. Specific attention was made to reproduce properties that impact compositional segregation, material strength, and mechanics. Utilizing the MEAM interatomic potentials and a Monte Carlo scheme, phase segregation in the CrNiCo, CuNiCr and CuNiCo fcc alloys …

Experimental And Numerical Investigation Of Droplet Dynamics In Microscale Systems: The Influence Of Surfactants And Nanoparticles On Environmental Applications, Negin Bahadori

Master's Theses

Emulsions are suspensions of droplets dispersed into an immiscible liquid phase, with at least a water phase and an oil phase. The capability to incorporate both hydrophilic and hydrophobic components makes emulsions amenable to a variety of applications, such as bilgewater treatment and oil recovery. To optimize bilgewater treatment or oil recovery, many aspects must be considered, such as the effect of emulsion stability, the wetting conditions and, more in general, the possibility to characterize droplet’s behavior over static or dynamic conditions. This thesis investigates the roles of surfactants and nanoparticles in understanding droplet behavior in oil-water systems, with a …

Machine Learning-Driven Process Analysis And Optimization In Solid-State Welding And Fusion-Based Additive Manufacturing, Radif Uddin Ahmed

Master's Theses

In the modern era of advanced manufacturing, optimizing process parameters is pivotal in ensuring the quality and reliability of sophisticated component fabrication. This study presents a novel, data-driven approach to parameter optimization in two cutting-edge manufacturing techniques: Friction Stir Welding (FSW) and Laser Powder Bed Fusion (LPBF). By leveraging machine learning methodologies, this research addresses the critical challenge of efficiently determining optimal process parameters, a task traditionally relying on time-consuming and resource-intensive trial-and-error methods. This study will lead to a robust data-driven framework for process analysis of more advanced manufacturing techniques like the Additive Friction Stir Deposition (AFSD) process. Friction …

Fringe-Field Actuation Of Mems Cantilever Resonators: Capacitance Model For Frequency-Amplitude Response Of Parametric Resonance, Miguel A. Martinez, Dumitru I. Carantu

Mechanical Engineering Faculty Publications

The paper investigates the frequency-amplitude response of micro-electromechanical system (MEMS) cantilever beams, which are actuated by the fringe field at parametric resonance. In this design, a micro cantilever beam (flexible electrode) and a ground plate (fixed electrode) are placed in parallel and connected through an AC voltage. The electrostatic force is due to electric field lines within the volume directly between the cantilever and the ground plate. The parallel-plate capacitance is directly related to the overlapping area of the two electrodes. However, to accurately compute the capacitance of the two electrodes, the effects due to the fringing field must be …

Control Of Multiagent Networks With Misbehaving Nodes, Emre Yildirim

USF Tampa Graduate Theses and Dissertations

The overarching objective of this dissertation is to introduce system theoretical frameworks in control of misbehaving multiagent networks subject to limited resources (i.e., limited number of driver nodes), and the presence of disturbances and/or uncertainties (i.e., misbehaving nodes). Below, we briefly summarize each problem studied in this dissertation with their proposed solutions.

Specifically, we first consider multiagent networks subject to misbehaving nodes over fixed undirected graph topologies. To address this problem, we apply proportional-integral control signals to a subset of nodes (i.e., driver nodes) in the network to address the undesired effects arising from misbehaving nodes. Since multiagent networks with …

A Study Of Fit And Friction Force As A Function Of The Printing Process For Fff 3d-Printed Piston–Cylinder Assembly, Philippe A. Passeraub, Quentin Allen, Elizabeth Clark, Michael Miles, Siddartha Berns, Maija Pearson, Sterling Allred, Jonah Brooks, Sylvain Hugon

ScholarsArchive Data

Dataset DOI: https://doi.org/10.26067/hjm6-3d45

The shared data comprises the experimental measurements performed presented in the figures 5, 6, 7, 9, 10, 11, 12, and in the tables for the following article:

Passeraub, P.A.; Allen, Q.; Clark, E.; Miles, M.; Berns, S.; Pearson, M.; Allred, S.; Brooks, J.; Hugon, S. A Study of Fit and Friction Force as a Function of the Printing Process for FFF 3D-Printed Piston–Cylinder Assembly. J. Manuf. Mater. Process. 2024, 8, 249. https://doi.org/10.3390/jmmp8060249

Atmosphere Effects In Laser Powder Bed Fusion: A Review, Ben Brown, Cody Lough, Davis Wilson, Joseph Newkirk, Frank Liou

Materials Science and Engineering Faculty Research & Creative Works

The use of components fabricated by laser powder bed fusion (LPBF) requires the development of processing parameters that can produce high-quality material. Manipulating the most commonly identified critical build parameters (e.g., laser power, laser scan speed, and layer thickness) on LPBF equipment can generate acceptable parts for established materials and moderately intricate part geometries. The need to fabricate increasingly complex parts from unique materials drives the limited research into LPBF process control using underutilized parameters, such as atmosphere composition and pressure. As presented in this review, manipulating atmosphere composition and pressure in laser beam welding has been shown to expand …

Analysis, Design, And Experimental Validation Of The Thermal Subsystem Of Alainsat-1 Cubesat, Ameereh Seyedzadeh

Theses

This thesis investigates the thermal management techniques of AlAinSat-1 during extremely harsh space conditions. It presents a comprehensive analysis of its thermal behavior using numerical techniques and validates the CubeSat's survivability in space via experimental testing. AlAinSat-1 is a nanocube-shaped satellite carrying Earth observation payloads, including RITA (Remote sensing and Interference detector with radiome-Try and vegetation Analysis) and Locana. Understanding how the CubeSat behaves in harsh space conditions and maintains thermal stability during its mission is critical to its success. The main aim of this study is to employ finite element analysis (FEA) techniques to simulate the thermal behavior of …

Design And Implementation Of Attitude Control System For Gnssas 6u Cubesat, Anoud Nasser Alkatheeri

Theses

This thesis presents the design and simulation of the Attitude Control System (ACS) for the GNSSaS 6U CubeSat, developed by the National Space Science and Technology Center (NSSTC) at UAE University. The CubeSat's mission is to enhance GNSS signal accuracy, which requires precise attitude control to achieve this objective. The ACS utilizes magnetorquers and reaction wheels for actuation. The primary objective of this thesis is to design an ACS that fulfills the mission’s performance requirements, including maintaining pointing accuracy in both fine and medium pointing modes. To achieve this, a comprehensive disturbance analysis was conducted, leading to the selection of …