Mechanical Engineering Commons^™

Post-Polymerization Modification Of Kapton Using Electron Beam Irradiation, Luis A. Hernandez

Mechanical Engineering ETDs

In the present study, the feasibility of chemical modification of electron-irradiated Kapton is investigated. Characterization techniques determined the changes between a pristine, electron irradiated, and a chemically treated, i.e., fluorinated, sample of Kapton. Kapton is a common material in space application as it serves as the exterior surface for space vehicles. Highly aged Kapton have significant material property changes, making them prone to electro-static discharge (ESD) damage. Understanding how Kapton material behaves under space conditions and the possibility of improving its structure and properties is of utmost important. To this end, changes to the physical properties of the material were …

Design Of A Canine Inspired Quadruped Robot As A Platform For Synthetic Neural Network Control, Cody Warren Scharzenberger

Dissertations and Theses

Legged locomotion is a feat ubiquitous throughout the animal kingdom, but modern robots still fall far short of similar achievements. This paper presents the design of a canine-inspired quadruped robot named DoggyDeux as a platform for synthetic neural network (SNN) research that may be one avenue for robots to attain animal-like agility and adaptability. DoggyDeux features a fully 3D printed frame, 24 braided pneumatic actuators (BPAs) that drive four 3-DOF limbs in antagonistic extensor-flexor pairs, and an electrical system that allows it to respond to commands from a SNN comprised of central pattern generators (CPGs). Compared to the previous version …

Modeling Thermal And Mechanical Cancellation Of Residual Stress From Hybrid Additive Manufacturing By Laser Peening, Guru Madireddy, Chao Li, Jingfu Liu, Michael P. Sealy

Department of Mechanical and Materials Engineering: Faculty Publications

Additive manufacturing (AM) of metals often results in parts with unfavorable mechanical properties. Laser peening (LP) is a high strain rate mechanical surface treatment that hammers a workpiece and induces favorable mechanical properties. Peening strain hardens a surface and imparts compressive residual stresses improving the mechanical properties of a material. This work investigates the role of LP on layer-by-layer processing of 3D printed metals using finite element analysis. The objective is to understand temporal and spatial residual stress development after thermal and mechanical cancellation caused by cyclically coupling printing and peening. Results indicate layer peening frequency is a critical process …

Interactions Of Bacteria With Monolithic Lateral Silicon Nanospikes Inside A Microfluidic Channel, Lei Li, Feng Tian, Hao Chang, Jie Zhang, Cheng Wang, Wei Rao, Huan Hu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper presents a new strategy of integrating lateral silicon nanospikes using metal-assisted chemical etching (MacEtch) on the sidewall of micropillars for on-chip bacterial study. Silicon nanospikes have been reported to be able to kill bacteria without using chemicals and offer a new route to kill bacteria and can prevent the overuse of antibiotics to reduce bacteria. We demonstrated a new methodology to fabricate a chip with integrated silicon nanospikes onto the sidewalls of micropillars inside the microfluidic channel and attested its interactions with the representative gram-negative bacteria Escherichia coli. The results of colony-forming unit (CFU) calculation showed that 80% …

City Of New Smyrna Beach Solar Feasibility Assessment - City Hall Annex, Florida Solar Energy Center, Charles Withers, Jr.

FSEC Energy Research Center®

This review and solar assessment is organized by component with brief description of intended details, challenges and recommendations.

Building: City of New Smyrna Beach, City Hall Annex (Renovation of a portion of the Historic First Baptist Church of New Smyrna Beach) Year of Construction: 1920's[1] Building Use: Renovation will create spaces for City workers and a new City Council Chambers Conditioned area: 1^st floor = 7856 ft² 2^nd floor = 3,967 ft² Total = 11,823 ft²[2]

[1] New Smyrna Beach Property Appraiser's website states 1920, historic marker states circa 1929. [2] New Smyrna …

Method For Fabrication Of A Soft-Matter Printed Circuit Board, Carmel Majidi, Tong Lu, Eric J. Markvicka

Department of Mechanical and Materials Engineering: Faculty Publications

A fabrication process for soft - matter printed circuit boards is disclosed in which traces of liquid - phase Ga - In eutectic ( eGaIn ) are patterned with UV laser micromachining ( UVLM ) . The terminals of the elastomer - sealed LM circuit connect to the surface mounted chips through vertically aligned columns of eGaIn - coated ferromagnetic micro spheres that are embedded within an interfacial elastomer layer .

How Vision Governs The Collective Behaviour Of Dense Cycling Pelotons, J. Belden, Mohammad M. Mansoor, A. Hellum, S. R. Rahman, A. Meyer, C. Pease, J. Pacheco, S. Koziol, Tadd T. Truscott

Mechanical and Aerospace Engineering Faculty Publications

In densely packed groups demonstrating collective behaviour, such as bird flocks, fish schools or packs of bicycle racers (cycling pelotons), information propagates over a network, with individuals sensing and reacting to stimuli over relatively short space and time scales. What remains elusive is a robust, mechanistic understanding of how sensory system properties affect interactions, information propagation and emergent behaviour. Here, we show through direct observation how the spatio-temporal limits of the human visual sensory system govern local interactions and set the network structure in large, dense collections of cyclists. We found that cyclists align in patterns within a ± 30° …

Microfluidic Gasketless Interconnect Sealed By Superhydrophobic Surfaces, Xiaoxiao Zhao

LSU Doctoral Dissertations

Lab-on-a-chip technologies are widely applied in the field of life sciences and potentially in clinical diagnostics. There is a high demand for standardized, efficient interconnects between components in modular microfluidic systems. Chip-to-chip contactless, microfluidic interconnects, that allow fluid flow between chips, were designed and evaluated. The interconnects are 'gasketless' without the need for O-ring’s or fillers. Specifically, two microfluidic chips are assembled face-to-face and the fluidic ports on each chip were accurately aligned to allow the passage of fluids, through liquid bridges spanning the gap. Formation of the liquid bridges was governed by superhydrophobic films coating the surface around the …

Pseudo-Spectral Method To Control Three-Degree-Of-Freedom Wave Energy Converters, Ossama Abdelkhalik, Giorgio Bacelli, Shangyan Zou, Rush D. Robinett Iii, David G. Wilson, Ryan G. Coe

Michigan Tech Patents

The invention provides optimal control of a three-degree-of-freedom wave energy converter using a pseudo-spectral control method. The three modes are the heave, pitch and surge. A dynamic model is characterized by a coupling between the pitch and surge modes, while the heave is decoupled. The heave, however, excites the pitch motion through nonlinear parametric excitation in the pitch mode. The invention can use a Fourier series as basis functions to approximate the states and the control. For the parametric excited case, a sequential quadratic programming approach can be implemented to numerically solve for the optimal control. The numerical results show …

Characterization Of Single- And Multi-Phase Shock-Accelerated Flows, Patrick John Wayne

Mechanical Engineering ETDs

Experiments conducted in the Shock Tube Facility at the University of New Mexico are focused on characterization of shock-accelerated flows. Single-phase (gaseous) initial conditions consist of a heavy gas column of sulfur hexafluoride seeded with approximately 11% acetone gas by mass. Visualization of the image plane for gaseous initial conditions is accomplished via planar laser-induced fluorescence (PLIF) with a high-powered Nd:YAG ultraviolet laser and an Apogee Alta U-42 monochrome CCD camera, with a quantum efficiency > 90%. Multi-phase (gas-solid) initial conditions consist of glass micro-beads deposited on small 1-cm diameter discs of specific surface chemistry, mounted flush with the bottom wall …

Investigation Of Through Thickness Microstructure And Mechanical Properties In Friction Stir Welded 7n01 Aluminum Alloy Plate, Xingxin Zhao, Zhiyong Yang, Joseph P. Domblesky, Jianmin Han, Zhiqiang Li, Xiaolong Liu

Mechanical Engineering Faculty Research and Publications

An on-going problem in friction stir welded (FSW) joints used in the high-speed train sector is that the microstructure and mechanical properties can significantly vary in thick sections. Because inhomogeneous properties can reduce weld efficiency and degrade service performance, it is of some interest to understand how inhomogeneous properties can develop in FSW welds made from precipitation hardening alloys such as 7N01. In the current study, butt welds were made using 12 mm thick plates and then sectioned perpendicular to the weld line. Five 2.2 mm thick slices were cut from a section and used to measure tensile properties access …

Engineering Of Bio-Mimetic Substratum Topographies For Enhanced Early Colonization Of Filamentous Algae, Ali Khoshkhoo, Andres L. Carrano, David M. Blersch, Kamran Kardel

Manufacturing Engineering: Faculty Publications (2015-2023)

This work reveals a set of surface topography parameters that are significant for algal attachment to natural rock substrata. Topography analysis of rock surfaces from a stream identifies three descriptive areal parameters (Smr, Sv, and Sa) that correlate with the presence of natural periphyton community. A method was developed and validated to reverse engineer and manufacture artificial substrata with topographic complexity defined by these parameters, using computational modeling and additive manufacturing. Results from colonization experiments with filamentous algae show statistically significant increases in early biomass accrual rates on substrata with higher values of …

The Roussopoulos And Schwinger Functionals For Nuclear Systems Involving Imprecisely Known Fluxes And Parameters: Distinctions And Equivalences, Dan Gabriel Cacuci

Faculty Publications

For over 60 years, the Roussopoulos and Schwinger functionals have been used in many works and textbooks under the assumption that they provide “second-order accurate” trial functions for the forward and adjoint fluxes when computing reaction rates and/or particle detector responses in source-driven nuclear systems. The Schwinger functional has been employed as a particularly useful form of the Roussopoulos functional for systems in which the forward and adjoint particle fluxes were normalized. When using these functionals, however, the expressions for the approximate fluxes were postulated arbitrarily while the system parameters were unrealistically assumed to be perfectly well known. This work …

Design Of Variable Wall Thickness Geometry And Performance Mapping Of Scroll Expanders For Distributed Power Generation, Arun Kumar Narasimhan

USF Tampa Graduate Theses and Dissertations

Low-temperature heat sources such as industrial waste heat, solar, and geothermal are more suitable for small-scale power generation rather than utility scale. In order to maximize the electricity generated from low-temperature heat sources, an efficient expansion device for small-scale power output is necessary. This research work has focused on evaluating the use of a scroll expander and improving its geometrical design for the power output range of 1-25 kW_e.

The first part of the work focusses on modeling the performance of a scroll expander using two non-dimensionless parameters, namely, specific speed and specific diameter. Performance of a scroll …

High Enthalpy Storage Thermoset Network With Giant Stress And Energy Output In Rubbery State And Associated Applications, Jizhou Fan

LSU Doctoral Dissertations

In this study, a new shape memory thermoset network with giant stress and energy output in rubbery state is synthesized and studied firstly since the low output in stress and energy in rubbery state has been a bottleneck for wide-spread applications of thermoset shape memory polymers (SMPs). Traditionally, stress or energy storage in thermoset network is through entropy reduction by mechanical deformation or programming. We here report another mechanism for energy storage, which stores energy primarily through enthalpy increase by stretched bonds during programming. As compared to entropy-driven counterparts, which usually have a stable recovery stress from tenths to several …

Teaching Top-Down Approaches To The Engineering Design Process, Joshua E. Katz, Joshua E. Katz

STAR Program Research Presentations

One of the main focuses of metacognition is to have students think about their learning. By bringing the engineering design process with educational psychology together, it can lead to a society that thinks more in-depth on various topics. The goal of the internship was to utilize and teach top-down educational and instructional objectives. Throughout the project, we followed a modified progression of the System Architecture Methodology to help other interns think in a top-down fashion. The purpose of this procedure is to create and induce new innovative and creative ideas for different projects. As teaching this methodology was tasked, research …

Energy Transformation And Conservation Investigation, Mike Jackson, Holly Haney

High School Lesson Plans

Students will use a thermoelectric generator module to analyze the relationship between thermal and electrical energies. Using data collection sensors and analysis software, students will investigate the relationship between the temperature gradient across a thermoelectric generator module and the resulting electrical potential. Students will then use their data and analysis to solve problems relating to waste thermal energy in electrical systems and communicate their work to their peers and teacher.

Application And Evaluation Of Full-Field Surrogate Models In Engineering Design Space Exploration, Christopher Murray Thelin

Theses and Dissertations

When designing an engineering part, better decisions are made by exploring the entire space of design variations. This design space exploration (DSE) may be accomplished manually or via optimization. In engineering, evaluating a design during DSE often consists of running expensive simulations, such as finite element analysis (FEA) in order to understand the structural response to design changes. The computational cost of these simulations can make thorough DSE infeasible, and only a relatively small subset of the designs are explored. Surrogate models have been used to make cheap predictions of certain simulation results. Commonly, these models only predict single values …

Maquiladoras In Central America: An Analysis Of Workforce Schedule, Productivity And Fatigue., Jose L. Barahona

Masters Theses & Specialist Projects

Textile factories or Maquiladoras are very abundant and predominant in Central American economies. However, they all do not have the same standardized work schedule or routines. Most of the Maquiladoras only follow schedules and regulations established by the current labor laws without taking into consideration many variables within their organization that could affect their overall performance. As a result, the purpose of the study is to analyze the current working structure of a textile Maquiladora and determine the most suitable schedule that will abide with the current working structure but also increase production levels, employee morale and decrease employee fatigue. …

Bioprinting With Human Stem Cell-Laden Alginate-Gelatin Bioink And Bioactive Glass For Tissue Engineering, Krishna C. R. Kolan, Julie A. Semon, Bradley Bromet, D. E. Day, Ming-Chuan Leu

Biological Sciences Faculty Research & Creative Works

Three-dimensional (3D) bioprinting technologies have shown great potential in the fabrication of 3D models for different human tissues. Stem cells are an attractive cell source in tissue engineering as they can be directed by material and environmental cues to differentiate into multiple cell types for tissue repair and regeneration. In this study, we investigate the viability of human adipose-derived mesenchymal stem cells (ASCs) in alginate-gelatin (Alg-Gel) hydrogel bioprinted with or without bioactive glass. Highly angiogenic borate bioactive glass (13-93B3) in 50 wt% is added to polycaprolactone (PCL) to fabricate scaffolds using a solvent-based extrusion 3D bioprinting technique. The fabricated scaffolds …

Distributed State Estimation By Using Active-Passive Sensor Networks, Akhilesh Raj, S. Jagannathan, Tansel Yucelen

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes a novel adaptive observer for heterogeneous sensor networks (HSNs) to estimate state vector of an unknown target or process by using the sensed output when the input to the target/process is also not known. In an HSN, nodes are considered either active or passive depending upon their ability to sense the target output. The local information exchange among the nodes is dictated by a connected graph. By using the criterion of collective observability, a novel distributed adaptive estimation is introduced where the nodes are allowed to have different sensor modalities. Stability analysis shows uniform ultimate boundedness of …

Investigation Of Fundamental Principles Of Rigid Body Impact Mechanics, Khalid Alluhydan

Mechanical Engineering Research Theses and Dissertations

In impact mechanics, the collision between two or more bodies is a common, yet a very challenging problem. Producing analytical solutions that can predict the post-collision motion of the colliding bodies require consistent modeling of the dynamics of the colliding bodies. This dissertation presents a new method for solving the two and multibody impact problems that can be used to predict the post-collision motion of the colliding bodies. Also, we solve the rigid body collision problem of planar kinematic chains with multiple contacts with external surfaces.

In the first part of this dissertation, we study planar collisions of Balls and …

Endogenous Force Transmission Between Epithelial Cells And A Role For Α-Catenin, Sandeep Dumbali

Mechanical & Aerospace Engineering Theses & Dissertations

In epithelial tissues, epithelial cells adhere to each other as well as to the underlying extra-cellular matrix (ECM). E-cadherin-based intercellular junctions play an important role in tissue integrity. These junctions experience cell-generated mechanical forces via apparent adaptor proteins such as beta (β) catenin, alpha (α) catenin and vinculin. Abnormalities in these junctions may result in skin related diseases and cancers. Here, I devised methods to determine the endogenous intercellular force within cell pairs as well as in large epithelial islands. I further ascertained the factors that affect the level of inter-cellular tension.

Experiments with pairs of epithelial cells exogenously expressing …

Active-Passive Dynamic Consensus Filters For Linear Time-Invariant Multiagent Systems, J. Daniel Peterson, Tansel Yucelen, S. Jagannathan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Active-passive dynamic consensus filters consist of a group of agents, where a subset of these agents is able to observe a quantity of interest (i.e. active agents) and the rest are subject to no observations (i.e. passive agents). Specifically, the objective of these filters is that the states of all agents are required to converge to the weighted average of the set of observations sensed by the active agents. Existing active-passive dynamic consensus filters in the classical sense assume that all agents can be modeled as having single integrator dynamics, which may not always hold in practice. Motivating from this …

Stabilization Of Homoclinic Orbits Of Two Degree-Of-Freedom Underactuated Systems, Nilay Kant, Ranjan Mukherjee, Hassan K. Khalil

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A hybrid controller for stabilization of homoclinic orbits of two degree-of-freedom (DOF) underactuated systems is proposed. The controller is comprised of continuous-time inputs, impulsive brakings, and virtual impulsive inputs for resetting of the passive coordinate. Impulsive brakings of the active coordinate result in instantaneous negative changes in the mechanical energy of the system. An impulsive dynamical system framework is adopted for modeling the hybrid dynamics and a Lyapunov function is defined for stabilization of the orbit. Sufficient conditions for stabilization are presented such that the Lyapunov function decreases monotonically under the action of the continuous inputs and undergoes negative jumps …

Electronic Cvt - Controls, Alec William Hardy, Jessalyn Leora Ann Bernick, Nicholas Esteban Capdevila, Tristan Charles Perry

Mechanical Engineering

The following document outlines the design process, manufacturing, and testing of the control system for an electronically controlled continuously variable transmission (ECVT). This control system was integrated into the custom designed and manufactured mechanical transmission system created in parallel by another senior project group. The transmission was designed for use in the Cal Poly Baja SAE vehicle. Through researching customer needs, competition requirements, previous and alternate CVT designs, and vehicle characteristics, we were able to determine the requirements and specifications for our unique system. Input, output, speed, and durability requirements guided our hardware selection. The primary components which comprised our …

Performance Analysis Of A Parabolic Trough Solar Collector, Feras Abdullah Mohammed Alghamdi

Theses and Dissertations

Solar energy technologies are growing vastly in both developed and developing countries. The parabolic trough solar collector (PTSC) technology is the most widely used system among concentrated solar technologies. In this thesis, three models were developed to investigate the performance of the PTSC; these models are 2D & 3D numerical models and 1D analytical model. Each model considers three absorber tube configurations, vacuum annulus, air-filled annulus, and bare absorber tube. The specifications of the Luz LS-2 PTSC were used throughout the study. Since the study considers the 3D model, a realistic non-uniform heat flux distribution around the receiver tube was …

Reducing The Noise Impact Of Unmanned Aerial Vehicles By Flight Control System Augmentation, Matthew B. Galles

Mechanical & Aerospace Engineering Theses & Dissertations

The aim of this thesis is to explore methods to reduce the noise impact of unmanned aerial vehicles operating within acoustically sensitive environments by flight control system augmentation. Two methods are investigated and include: (i) reduction of sound generated by vehicle speed control while flying along a nominal path and (ii) reduction of acoustic exposure by vehicle path control while flying at a nominal speed. Both methods require incorporation of an acoustic model into the flight control system as an additional control objective and an acoustic metric to characterize primary noise sources dependent on vehicle state. An acoustic model was …

A Set-Theoretic Model Reference Adaptive Control Architecture With Dead-Zone Effect, Ehsan Arabi, Tansel Yucelen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

By introducing a system error dependent learning rate, the recently proposed set-theoretic model reference adaptive control architecture provides user-defined worst-case performance guarantees on the system error between an uncertain dynamical system of interest and a given reference model. In this architecture, the adaptation process is always active. However, it is of practical interest to stop the adaptation process when it is not needed (i.e., in the presence of small system errors). Motivated from this standpoint, we present a new set-theoretic model reference adaptive control architecture with dead-zone effect. The key feature of our framework utilizes a modified and continuous generalized …

Event-Triggered Adaptive Distributed State Estimation By Using Active-Passive Sensor Networks, Akhilesh Raj, S. Jagannathan, Tansel Yucelen

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes a novel event-triggered adaptive observer for each node in the heterogeneous sensor networks (HSNs) in order to estimate state vector of an unknown target or process by using the sensed output when the input to the target/ process is unknown. A subset of nodes in the HSN referred to as active nodes, can sense the target periodically, estimate the target state vector by using their adaptive observer and can communicate the estimated state vector of the target with the neighboring nodes including passive nodes only at event triggered instants. The adaptive observer parameters of active nodes are …