Engineering Commons^™

Gas Chromatography Micro-Chip With High Temperature Interface And Silk Screen Heaters, Carlos R. Vilorio

Theses and Dissertations

There has been substantial market demand for a portable Gas Chromatography (GC) system. Throughout the years, much progress has been made on fabricating a micro system that works as well as a benchtop system. Unfortunately, even though many substrates, channel types, channel widths, temperature control systems, and interface solutions have been attempted, existing versions of the micro-GC still fall short of the ideal. This thesis presents the design, fabrication, and testing of a silicon based micro-GC column that presents a solution for interfacing and heating of the chip. A polyimide resin is used to create a durable high temperature low …

Improved Analysis Techniques For Scatterometer Wind Estimation, Gregory Dallin Schachterle

Theses and Dissertations

In this thesis, three improved analysis techniques for scatterometer wind estimation are presented. These techniques build upon previous methods that help validate scatterometer data. This thesis examines the theory connecting the 1D and 2D kinetic energy spectra and uses QuikSCAT data to measure the 2D kinetic energy spectrum of ocean winds. The measured 2D kinetic energy spectrum is compared to the traditional 1D kinetic energy spectrum. The relationship between the 2D kinetic energy spectra and the 1D kinetic energy spectra confirms findings from previous studies that ocean winds modeled in 2D are isotropic and nondivergent. The 1D and 2D kinetic …

Assessing The Effects Of Reconstruction On The Commercial And Civil Construction Industry Following Hurricane Maria In Puerto Rico, Timothy Jafek Barrett-Rodriguez

Theses and Dissertations

In September 2017 Hurricane Maria made landfall on the U.S territory island of Puerto Rico, causing substantial damage to the already weakened infrastructure and other aspects of the built environment. This research attempted to identify the challenges and opportunities that have been encountered within the Puerto Rican commercial and civil construction industry during the first year of reconstruction, post-Hurricane Maria. This was done by identifying the effects of the storm as well as the strategies of construction companies involved in the reconstruction process. The study used the events occurring after the passing of the hurricane as a case study to …

Lateral Resistance Of Grouped Piles Near 20-Ft Tall Mse Abutment Wall With Strip Reinforcements, Zachary Paul Farnsworth

Theses and Dissertations

A team from Brigham Young University and I performed full-scale lateral load tests on individual and grouped 12.75x0.375 inch pipe piles spaced at varying distances behind an MSE wall. The individually loaded pile which acted as a control was spaced at 4.0 pile diameters from the wall face, and the three grouped piles which were loaded in unison were spaced at 3.0, 2.8, and 1.8 pile diameters from the wall face and transversely spaced at 4.7 pile diameters center-to-center. The purpose of these tests was to determine the extent of group effects on lateral pile resistance, induced loads in soil …

Technology And Tactics As Dimensions Of Design: Explicit Representation Of User Actions In The Product Design Space, Tyler Stapleton

Theses and Dissertations

The initial phases of the design process -- including interactions with stakeholders, ideation of concept candidates, and the selection of the best candidates --- have a large impact on the success of a project as a whole. Much of the value generated during these phases comes from the designers' exploration of the design space as they create concepts for the final solution. Unfortunately, an entire dimension of the design space is often ignored during the initial phases of the design process -- the tactics dimension. Engineers tend to emphasize the design of technology in their work, while paying less attention …

Characterization And Optimization Of An Image Charge Detector For The Measurement Of Martian Dust, Jace Rozsa

Theses and Dissertations

Image charge detector (ICD) technology has existed for decades. However, not until recently has an ICD been proposed for use in space exploration, specifically for studying the characteristics of the dust on Mars. Characterizing the dust on Mars is crucial for designing equipment to aid manned missions. It also improves our understanding of Mars' climate and weather systems. An ICD utilizing printed circuit board (PCB) electrodes, coupled with a custom differential amplifier, is best suited for this type of measurement because of its light weight, simplicity, and noise performance. The noise floor of our particular amplifier is measured to be …

A Framework For Simulating And Analyzing Multi-Uav Persistent Search And Retrieval With Stochastic Target Appearance, Ryan David Day

Theses and Dissertations

In recent years, advances in small unmanned aerial vehicle (UAV) technology have transformed the use cases of these aircraft from hobby flying to industrial and business applications. These maneuverable, easily deployed tools can be retrofitted with a myriad of sensors and equipment, which make them suitable to perform a variety of specialized tasks. With increasing UAV capabilities, the function of small UAVs can be extended from pure monitoring or surveillance to the dual objective of monitoring an environment for events and addressing the events in some way. This thesis seeks to explore a subdomain of the dual objective problem described, …

Linbo3 Waveguide Modulators: A Gateway To Realizing Holovideo Technology, Jeffrey Christopher Leach

Theses and Dissertations

In this dissertation, I will present the various work I have accomplished in regards to the design, simulation, and fabrication of holovideo and holodeck display technology. This includes: 1) design and analysis of a wavelength division multiplexing LiNbO3 waveguide device, 2) loss characterization and reduction (by way of reverse proton exchange) 3) design of a curved, near-eye AR display, and 4) a basis for acoustic holodeck technology (meant to service a system built from our optical devices). All these accomplishments represent, in concert, a manifestation of LiNbO3's capacity to serve as the building material central to modern holovideo displays. It …

Defect Detection In Friction Stir Welding By Measureable Signals, Johnathon Bryce Hunt

Theses and Dissertations

Friction stir welding (FSW) is an advantageous solid-state joining process, suitable for many materials in the energy, aerospace, naval and automotive industries. Like all other welding processes, friction stir welding requires non-destructive evaluation (NDE). The time and resources to preform NDE is expensive. To reduce these costs, nontraditional NDE methods are being developed for FSW. Spectral based defect recognition uses the forces during the welding process to validate weld quality. Although spectral NDE methods have shown promise as an alternative NDE processes, many research welding speeds do not correspond to manufacturing speeds, nor do they explain the relationship between the …

High-Precision, Mixed-Signal Mismatch Measurement Of Metal-Oxide-Metal Capacitors And A 13-Ghz 5-Bit 360-Degree Phase Shifter, Danilo Bustamante

Theses and Dissertations

A high-precision mixed-signal mismatch measurement technique for metal-oxide metal (MoM) capacitors as well as the design of a 13-GHz 5-bit 360-degree phase shifter are presented. This thesis presents a high-precision, mixed-signal mismatch measurement technique for metal-oxide–metal capacitors. The proposed technique incorporates a switched-capacitor op amp within the measurement circuit to significantly improve the measurement precision while relaxing the resolution requirement on the backend analog-to-digital converter (ADC). The proposed technique is also robust against multiple types of errors. A detailed analysis is presented to quantify the sensitivity improvement of the proposed technique over the conventional one. In addition, this thesis proposes …

Inter-Core Interference Mitigation In A Mixed Criticality System, Michael Glenn Hinton

Theses and Dissertations

In this thesis, we evaluate how well isolation can be achieved between two virtual machines within a mixed criticality system on a multi-core processor. We achieve this isolation with Jailhouse, an open-source, minimalist hypervisor. We then enhance Jailhouse with core throttling, a technique we use to minimize inter-core interference between VMs. Then, we run workloads with and without core throttling to determine the effect throttling has on interference between a non-real time VM and a real-time VM. We find that Jailhouse provides excellent isolation between VMs even without throttling, and that core throttling suppresses the remaining inter-core interference to a …

Analysis Of Inlet Distortion Patterns On Distortion Transfer And Generation Through A Highly Loaded Fan Stage, Andrew Dallin Orme

Theses and Dissertations

Characterization of distortion transfer and generation through fans with distorted inlet conditions enables progress towards designs with improved distortion tolerance. The abruptness of transition from undistorted to distorted total pressure regions at the inlet impacts the induced swirl profile and therefore the distortion transfer and generation. These impacts are characterized using URANS simulations of PBS Rotor 4 geometry under a variety of inlet distortion profiles. A 90° and a 135° sector, both of 15% total pressure distortion, are considered. Variants of each sector size, with decreasing levels of distortion transition abruptness, are each applied to the fan. Fourier-based distortion descriptors …

Investigation Of Isotruss® Structures In Compression Using Numerical, Dimensional, And Optimization Methods, Hanna Belle Opdahl

Theses and Dissertations

The purpose of this research is to investigate the structural efficiency of 8-node IsoTruss structures subject to uniaxial compression using numerical, dimensional, and optimization methods. The structures analyzed herein are based on graphite/epoxy specimens that were designed for light-weight space applications, and are approximately 10 ft. (3 m) long and 0.3 lb. (0.14 kg). The principal failure modes considered are material failure, global buckling, local buckling at the bay level, and longitudinal strut buckling. Studies were performed with the following objectives: to correlate finite element predictions with experimental and analytical methods; to derive analytical expressions to predict bay-level buckling; to …

Co-Milling And Cofiring Of Woody Biomass With Coal In Utility Boilers: Enabling Technology Through Experiments And Modelling, Seyedhassan Fakourian

Theses and Dissertations

Beetle-killed trees and woody residues degenerate and may lead to wildfires and uncontrolled CO2 emission. Woody biomass is known as a neutral CO2 solid fuel since it generates the same amount of CO2 that takes from atmosphere during its growing up. Cofiring woody biomass with coal in existing coal power plants is a reasonable solution to reduce the net amount of CO2 emission and decrease the risk of wildfires. However, there are some challenges ranging from providing and handling the woody biomass to the operation of cofiring woody biomass with coal. Co-milling of the fuels and ash deposition on the …

On Creases And Curved Links: Design Approaches For Predicting And Customizing Behaviors In Origami-Based And Developable Mechanisms, Jared J. Butler

Theses and Dissertations

This work develops models and tools to help designers address the challenges associated with designing origami-based and developable mechanisms. These models utilize strain energy, kinematics, compliant mechanisms, and graphical techniques to make the design of origami-based and developable mechanisms approachable and intuitive. Origami-based design tools are expanded through two methods. First presented is a generalized approach for identifying single-output mechanical advantage for a multiple-input compliant mechanism, such as many origami-based mechanisms. The model is used to predict the force-deflection behavior of an origami-based mechanism (Oriceps) and is verified with experimental data from magnetic actuation of the mechanism. Second is a …

Linear And Nonlinear Dimensionality-Reduction-Based Surrogate Models For Real-Time Design Space Exploration Of Structural Responses, Gregory David Bird

Theses and Dissertations

Design space exploration (DSE) is a tool used to evaluate and compare designs as part of the design selection process. While evaluating every possible design in a design space is infeasible, understanding design behavior and response throughout the design space may be accomplished by evaluating a subset of designs and interpolating between them using surrogate models. Surrogate modeling is a technique that uses low-cost calculations to approximate the outcome of more computationally expensive calculations or analyses, such as finite element analysis (FEA). While surrogates make quick predictions, accuracy is not guaranteed and must be considered. This research addressed the need …

Krahasimi I Energjisë Fosile Dhe I Energjisë Së Ripërtëritshme Në Kosovë, Visar Bejta

Theses and Dissertations

Një ndër pyetjet thelbësore në rrafshin ekonomik bashkëkohor të shekullit XXI është edhe ajo përkitazi me metodën më efikase të prodhimit të energjisë në mbështetje të sferave të ndryshme jetësore dhe sociale. Burimet fosile të energjisë, në veçanti ato nga qymyrguri, shërbejnë për prodhimin e shumicës së energjisë elektrike në Kosovë, ndërsa një pjesë e vogël përftohet nga burimet e ripërtëritshme. Ndopak më saktësisht, rreth 90-95% e energjisë përftohet nga burimet fosile, teksa pjesa e mbetur gjen prejardhjen në burimet eripërtëritshme.

Kosova, tashmë, është në etapën e tranzicionit të energjisë, duke zbatuar dhe jetësuar direktivat dhe caqet e përcaktuara nga …

“Qëndrueshmëria E Prodhimit Të Energjisë Nga Lëndët Fosile Dhe Bre Në Kosove”, Djellza Prebreza

Theses and Dissertations

Zhvillimi i tregut energjetik dhe veqanërisht energjia e ripërtëritshme po zë një rol kyç në Kosovë, kjo mund të çoje njëkohësisht në stabilizimin e ekonomisë së re të vendit. Vetëm nga furnizimi i qëndrushëm, efikas dhe modern me energji mund të sigurohet zhvilliimi i shpejtë i industrive të reja.

Prodhimi i energjisë në Kosovë mbështetet nga lëndët fosile kryesisht qymyrguri, kurse një sasi e vogël e energjisë fitohet nga burimet e ripërtëritshme. Shfrytëzimi i lëndeve fosile ka ndikim të madh mjedisore e kjo na bën të mendojmë për një zgjidhje më të qëndrueshme dhe me më pak ndikim ambiental.

Në …

A Novel Design Of Broadband Antennas With A Defected Radiating Patch Structure For Wireless Communication Systems, Ali Giuma F Esseid

Theses and Dissertations

Generally, conventional wireless communication systems transfer data between two points through a channel, consisting of broadband with a multi-frequency band. Broadband or multiband is very important in wireless telecommunication devices. It is quickly advancing as high-speed and high-level data rate wireless modern communication technology. In wireless modern communication the antenna plays a very crucial role. Broadband with a multi-frequency band purpose has been the incitement of this research. However, there are a lot of challenges in designing and accomplishing a broadband with a multi-frequency band antenna than with a tight impedance bandwidth single antenna. Appropriate broadband with multi-frequency band antenna …

Airline Brand Experience Passengers’ Perceptions Of The Big Three Carriers In The United States, Sarinthree Udchachone

Theses and Dissertations

The purpose of the study was to observe passengers’ perceptions about brand experience research in the airline industry by applying a transcendental or descriptive phenomenological methodology designed to evaluate interview transcriptions and organize derived knowledge into defined themes. The NVivo program was utilized to analyze data from textual transcriptions. The experiences of passengers of the Big Three United States legacy carriers, including American Airlines, Delta Air Lines, and United Airlines, were described. The participants comprised three couples and seven individuals, all frequent-flyer members of the Big Three carriers and their partnering global airline alliances. The researcher-constructed instrument was used for …

Lead Free Piezoelectric And Triboelectric Energy Film For Energy Harvesting And Sensory Applications, Abu Musa Abdullah

Theses and Dissertations

In recent times, Triboelectricity and Piezoelectricity has been widely used for utilizing mechanical energy from ambient environment. Scientists are focusing towards developing advanced material composites for utilizing piezoelectricity and triboelectricity for energy harvesting and sensory applications. This work includes two projects regarding the application of lead free piezoelectric and triboelectric energy for energy harvesting and sensory applications. Human motion has been attributed as a source of mechanical energy to drive electronic devices and sensors through Triboelectric Nanogenerator (TENG). Based on the principles of single electrode TENG, we have developed a Triboelectricity based Stepping and Tapping Energy Case (TESTEC) which magnifies …

Development Of Plant Extract-Based Composite Fibers And Aerogels, Raul C. Barbosa

Theses and Dissertations

The aim of this study is to use the solid templating process of pullulan nanofibers in order to produce biocompatible, biodegradable, and antibacterial aerogels. The developed aerogels were produced using cross-linked pullulan nanofibers, which provide a water-stable structure allowing them to be used as wound dressing material. The morphology, thermal properties, water solubility, and thermal and physical properties of the nanofibers and aerogels were characterized. Furthermore, the antibacterial effect against gram-negative bacteria, Escherichia coli, and the biocompatibility using mouse embryonic fibroblasts (NIH 3T3) were investigated.

Experimental Study Of Graphene Energy Absorbing Layer In Femtosecond Infrared Laser Assisted Bioprinting, Chaoran Dou

Theses and Dissertations

The bioprinting, as a new branch of additive manufacturing, already shown its potential in organ transplantation, medicine develop and personalized medicine. There are three types of bioprinting: droplet based bioprinting, extrusion based bioprinting and laser assisted bioprinting (LAB). Compared with other types of bioprinting, the LAB is the only bioprinting method that does not have a nozzle, which gives it the ability to print high viscosity bioink. The LAB also enjoys higher resolution and cell viability than other methods.

The bubble/jet formation process is the most important process for the LAB, which deposits the bioink to the substrate. To utilize …

An Experimental Thrust Measurement Study On The Nozzle Asymmetry Of Turbulent Pulsed Jets, Cesar Alberto Leos Jr.

Theses and Dissertations

The resurgence of pulsejet engines has renewed the interest of the flow characteristics responsible for the high levels of thrust augmentation that are necessary for Vertical/Short Take-Off and Landing (V/STOL) aircraft. It is well known that pulsation of the engine plays an important role on the thrust performance, but many of the characteristics that are primarily responsible for these enhancements are not well understood. This study is carried out to elucidate the effect of nozzle exit Mach number and the nozzle exit geometry on the characteristics of a high Reynolds number (~105), turbulent free pulsed jet.

Direct thrust measurements are …

Signal Processing Combined With Machine Learning For Biomedical Applications, Md Shakhawat Hossain

Theses and Dissertations

The Master’s thesis is comprised of four projects in the realm of machine learning and signal processing. The abstract of the thesis is divided into four parts and presented as follows,

Abstract 1: A Kullback-Leibler Divergence-Based Predictor for Inter-Subject Associative BCI.

Inherent inter-subject variability in sensorimotor brain dynamics hinders the transferability of brain-computer interface (BCI) model parameters across subjects. An individual training session is essential for effective BCI control to compensate for variability. We report a Kullback-Leibler Divergence (KLD)-based predictor for inter-subject associative BCI. An online dataset comprising left/right hand, both feet, and tongue motor imagery tasks was used to …

Improving Hardware Implementation Of Cryptographic Aes Algorithm And The Block Cipher Modes Of Operation, Chu-Wen Cheng

Theses and Dissertations

With ever increasing Internet traffic, more business and financial transactions are being conducted online. This is even more so during these days of COVID-19 pandemic when traditional businesses such as traditional face to face educational systems have gone online requiring huge amount of data being exchanged over Internet. Increase in the volume of data sent over the Internet has also increased the security vulnerabilities such as challenging the confidentiality of data being sent over the Internet. Due to sheer volume, all data will need to be effectively encrypted. Due to increase in the volume of data, it is also important …

Beacon Aided Robotics For Martian Cave Mapping, Ryan Joseph Capozzi

Theses and Dissertations

At present, lava tubes on the Moon and Mars have been left wholly unexplored. There are many aspects of subterranean exploration that pose additional challenges over surface exploration, and one of these issues is in localization. This project seeks to expand upon the traditional communication beacon that is dropped behind a robotic operator in subterranean environments and make low cost and low power modifications to increase their functionality by making robot localization from these beacons possible. This has been tested with the use of LED beacons that could be easily added to current solutions and used for localization of the …

J-85 Model Development For Performance Optimization, Austin Childers

Theses and Dissertations

Larsen Motorsports is a local jet racing facility in Melbourne, Florida. Larsen Motorsports is a key partner with Florida Tech. Larsen Motorsports has a highly skilled manufacturing team along with a robust manufacturing capability. Through their team’s many years of racing Larsen Motorsports has tuned and developed engineering for both the J-60 and J-85 jet engines. These modifications vary from small design changes to production of components to entire system redesigns. One of the most extensive redesigns their team has developed is the afterburner section of the General Electric J-85 jet engine. Their team has designed and tuned the entire …

A Quantitative Analysis Of The Robinson R44 Performance Characteristics, Jon Carroll Holzman

Theses and Dissertations

The Robinson R44 is the most prolific civil helicopter in the world with over 6,000 delivered to customers since 1992. Approved for normal category flight by the FAA through 14 CFR Parts 21 and 27, the accompanying Pilot's Operating Handbook includes all performance material required under the same. Practical planning materials, such as cruise charts and accompanying fuel flow rates for various operational weights and density altitudes, however, are absent. This leaves a large gap in flight planning resources needed for an airframe which is currently being used in a broad range of demanding civil capacities to include offshore oil …

General Electric J85 Engine Flame Holder Tooling, Jacob Portugal

Theses and Dissertations

Larsen Motorsports competes in drag racing events all over the country using their jet power drag cars. These competitions are focused on getting the most performance out of the engine as possible by shaving weight off the vehicle and increasing the amount of power produced. One of the many factors in the amount of power produced by the car is the afterburner. Afterburners can increase thrust from ~3,000lb to ~5,000lb in a standard J85 engine. Due to this there is a good deal of attention paid to the efficiency and performance of the afterburner. The specific portion this thesis focused …