Engineering Commons^™

Strain Path Effect On Austenite Transformation And Ductility In Tbf 1180 Steel, Parker Kenneth Gibbs

Theses and Dissertations

TBF 1180 steel was studied under various conditions focusing on the correlation of ductility and amount of retained austenite. Samples were prepared from sheet stock and then strained using limiting dome height tooling (LDH), a standard uniaxial test frame, and a tensile stage for use in an electron microscope. The steel was observed in plane, biaxial, and uniaxial strain to determine its effect on retained austenite transformation and ultimately, ductility. Retained austenite was observed using a scanning electron microscope (SEM) equipped with an electron backscatter detector (EBSD) to distinguish the different phases present. Initial austenite levels were around 5% by …

Neutron Beam Testing Methodology And Results For A Complex Programmable Multiprocessor Soc, Jordan Daniel Anderson

Theses and Dissertations

The Xilinx Multiprocessor System-on-Chip (MPSoC) is a complex device that uses 16nm FinFET technology to combine multiple processors, a large amount of FPGA resources, and many I/O interfaces on a single chip die. These features make the MPSoC a high-performance and architecturally flexible device. The potential computing power makes the MPSoC ideal for many embedded applications including terrestrial and space applications. The MPSoC, however, does not have extensive radiation history as many other devices have. The extent of the effect that ionized particles may have on the MPSoC is not well established. To solve this problem, neutron radiation testing can …

Pedestrian Walking Speeds At Signalized Intersections In Utah, Jordi Jordan Berrett

Theses and Dissertations

The 2009 edition of the Manual on Uniform Traffic Control Devices (MUTCD) recommends a pedestrian walking speed of 3.5 feet per second for use in the timing of pedestrian clearance intervals at signalized intersections (reduced from 4.0 feet per second in the 2003 edition). Jurisdictions across the state of Utah continue to maintain pedestrian walking speeds of 4.0 feet per second for normal intersections with guidance on engineering judgement for areas where a lower pedestrian walking speed should be considered. In 2018, it was decided that the current state guidance with regard to pedestrian walking speeds be evaluated for any …

Analog Adaptive Calibration For Arbitrary Phased Array Configuration, Mark William Nielson

Theses and Dissertations

The development of phased array antenna systems requires considerable resources and time. Due to this constraint, the Naval Air Command (NAVAIR) needs a phased array that can be physically reconfigured to meet the demands of multiple missions without added development time or cost. This work develops and demonstrates a solution to this problem by implementing an adaptive calibration approach to the development of electronically steerable antennas (ESAs). In contrast to previous analog adaptive beamformer systems, this system allows for an arbitrary antenna configuration with a variable number of antenna elements and locations. A simulation model of arbitrary phased array configurations …

Effect Of Support, Preparations Methods, Ag Promotion And Nc Size On The Activity, Selectivity And Sintering Deactivation Of Supported Co Fischer-Tropsch Catalyst, Mahmood Rahmati

Theses and Dissertations

A series of silver-promoted, 20 wt% cobalt Fischer-Tropsch synthesis (FTS) catalysts supported on an alumina modified with 5 wt% silica were prepared using two methods: traditional incipient wetness impregnation (IWI) and a new solvent-deficient precipitation (SDP) technique. Catalysts containing silver promoter concentrations of 0.3, 0.6, 1.2, and 2.5 wt% were prepared using each of the two methods. Silver improved the reducibility of the cobalt significantly, lowering reduction temperatures by up to 100°C, and increasing the extent of reduction by up to 35%. Further, in both preparation methods, changing the silver loading altered the cobalt dispersion. The smallest Co crystallite size …

An Efficient Low Voltage Dc Microgrid With Power Array Conversion For Commercial Buildings, Zhiqing Wu

Theses and Dissertations

PV solar energy is becoming increasingly more prevalent in electricity generation for residential and commercial buildings. Since PV solar directly supplies DC power, a DC microgrid is an ideal platform for PV energy resource in building applications. Existing DC power converters typically have low power conversion efficiency at light and heavy load conditions. Much research has been done on efficiency improvement of DC converters, but material, technology, and manufacturing processes all impose limitations on efficiency gain. This paper addresses the efficiency improvement of a DC microgrid with a power array conversion (PAC) for a commercial building application. The PAC configuration …

Numerical Study On Seakeeping Performance Of Hydrofoil Assisted Submersible Trimaran (Hast), Yuchen Lin

Theses and Dissertations

The present study focuses on the seakeeping characteristics of Hydrofoil Assisted Submersible Trimaran (HAST). The seakeeping performance is an important part in ship design because it effects the comfort, control, resistance and safety. The motions in wave will reduce the performance of ship which is designed and optimized in calm water. The heave and pitch motions of HAST in calm water and regular waves have been investigated by STAR CCM+, a CFD analysis program. The theory of numerical simulation based on STAR CCM+ has been presented. The basic theory of seakeeping performance studies has been discussed. A series of simulations …

Nuclear Data Covariance Analysis Of An Energy Tuning Assembly For Simulating Nuclear Weapon Environments, Nicholas J. Quartemont

Theses and Dissertations

An energy tuning assembly was characterized to spectrally shape the National Ignition Facility neutron source to a notional thermonuclear and prompt fission neutron spectrum to approximate a boosted nuclear device. This research performed nuclear data covariance analysis to predict the performance of the energy tuning assembly to create the objective spectrum, assessed anticipated experimental outcomes, and determine the fission products produced in a highly enriched uranium foil in the sample cavity. Nuclear data covariance impacted the neutron fluence energy distribution by a few percent for a large energy range of the neutron fluence. Neutron flux unfolding techniques provided broad spectral …

Application Of Metamaterials For Multifunctional Satellite Bus Enabled Via Additive Manufacturing, Michael A. Macchia

Theses and Dissertations

Space systems require materials with superior stiffness to weight ratios to provide structural integrity while minimizing mass. Additive manufacturing processes enable the design of metamaterials that exceed the performance of naturally occurring materials in addition to allowing the integration of non-structural functions. This research explored the use of a high stiffness, high density, small melt pool track width AM material, Inconel 718, to enable the production of metamaterials with finer features possible than can possibly be created using a lower density aluminum alloy material. Various metamaterials were designed utilizing thin wall triply periodic minimal surface infilled sandwich structures. The performance …

A Focal Plane Array And Electronics Model For Cmos And Ccd Sensors In The Afit Sensor And Scene Emulation Tool (Asset), Fernando D. Fernandez

Theses and Dissertations

Electro-optical and infrared (EO/IR) sensor models are useful tools that can facilitate understanding a system's behavior without expensive and time-consuming testing of an actual system. EO/IR models are especially important to the military industry where truth data is required but is sometimes impractical to obtain through experimentation due to expense or difficulties in procuring hardware. This work describes implementation of a focal plane array (FPA) model of charge-coupled device (CCD) and complementary metal-oxide semiconductor (CMOS) photodetectors as a component in the Air Force Institute of Technology (AFIT) Sensor and Scene Emulation Tool (ASSET). The FPA model covers conversion of photo-generated …

Optical And Electron Paramagnetic Resonance Characterization Of Point Defects In Semiconductors, Elizabeth M. Scherrer

Theses and Dissertations

Point defects in two semiconductor materials, both with promising optical properties, are investigated. The first material, CdSiP₂, is a nonlinear optical material in which absorption bands due to point defects can hinder performance when used in frequency conversion applications in the infrared. The second material, Sn₂P₂S₆, is a photorefractive material where point defects with specific properties are needed to optimize response in dynamic holography applications. Electron paramagnetic resonance (EPR) spectroscopy is used to identify the electronic structure of defects and their charge states. Correlations between EPR spectra and optical absorption allow assignments …

Computational And Experimental Development Of 2d Anisotropic Photonic Crystal Metamaterials, James A. Ethridge

Theses and Dissertations

The future of optical devices involves manipulation of nanoscale structure in order to achieve full control over the properties of the device. In fields as diverse as directed energy, remote sensing, optical communications and optical computing, these devices promise to greatly improve performance and efficiency. To advance this further, novel samples that incorporate both photonic crystal (PhC) structure and metamaterial properties, known as PhC metamaterials, are proposed. These PhC metamaterials allow for complete control over the directionality of the light-matter interaction to serve in these new applications. To develop this technology, first, metamaterials with no PhC structure are fabricated using …

Characterization Of Mechanical Properties Of Thin-Film Li-Ion Batteryelectrodes From Laser Excitation And Measurements Ofzero-Group Velocity Resonances, Jing Yao

Theses and Dissertations

The mechanical properties of thin-film Li-ion battery electrodes are controlled by the micro structure of the constituent materials. In this work, a non-contact and non-destructive measurement of the mechanical properties of electrode films is performed by measurement of zero group velocity (ZGV) resonances. The ZGV Lamb wave modes of a solid bi-layer consisting of a thin metallic layer and a thin compliant coating layer are shown to be dependent on the Young's moduli, thicknesses, densities and Poisson ratios of the layers. Theoretical models are used to quantify the sensitivity of the ZGV resonances to changes in mechanical properties. Experimental ZGV …

Complexity Of Establishing Industrial Connectivity For Small And Medium Manufacturers With And Without Use Of Industrial Innovation Platforms, Brian Dale Russell

Theses and Dissertations

The manufacturing industry is continuously evolving as new practices and technology are adopted to improve productivity and remain competitive. There have been three well established manufacturing revolutions in recent history and some say that the fourth is occurring currently by the name of Smart Manufacturing, Indusrie 4.0, and others. This latest manufacturing revolution is highly dependent on industrial connectivity. This research aims to gage the ability of Industrial Innovation Platforms (IIPs) to reduce complexity of implementing base-line industrial connectivity for small and medium-sized enterprises (SMEs). The results of this study would be especially relevant to decision makers in industrial SMEs …

Human-Centered Enterprise Resource Maintenance Management, Sharon Sue Chinoy

Theses and Dissertations

In complex domains, maintenance personnel may be required to use multiple software tools for receiving status information and controlling resources across the enterprise. These tools have evolved to be effective for collecting status, but often lack integrated contextual information for personnel to understand failure event impact to the enterprise and operational mission. Through a human-centered design approach, salient concepts and semantically relevant maintenance information can be captured within a domain. This research will show that an ontology can be a useful method to establish a common frame of reference to promote better situation awareness and more effective decision-making and collaboration …

Carbon Capture And Synergistic Energy Storage: Performance And Uncertainty Quantification, Christopher Stephen Russell

Theses and Dissertations

Energy use around the world will rise in the coming decades. Renewable energy sources will help meet this demand, but renewable sources suffer from intermittency, uncontrollable power supply, geographic limitations, and other issues. Many of these issues can be mitigated by introducing energy storage technologies. These technologies facilitate load following and can effectively time-shift power. This analysis compares dedicated and synergistic energy storage technologies using energy efficiency as the primary metric.
Energy storage will help renewable sources come to the grid, but fossil fuels still dominate energy sources for decades to come in nearly all projections. Carbon capture technologies can …

Evaluation Of Unmanned Aircraft Flying Qualities Using A Stitched Learjet Model, Patrick M. Callaghan

Theses and Dissertations

In recent years, military UAVs have taken over missions that were too dull, dirty, or dangerous for manned aircraft. The increased demand has led to a build-fly-fix-fly development mentality, plaguing the early lifecycle with staggering mishap rates. Currently, MIL-STD-1797 lists flying qualities for UAVs as TBD, and the standards for manned fixed wing are inadequate when applied to UAVs. In an effort to expand the database of UAV flying qualities, an analysis was completed on a Simulink model of an LJ-25D developed from Calspans Variable Stability System aircraft at the United States Test Pilot School. Three maneuvers were simulated: (1) …

Magnetic Field Aided Indoor Navigation, William F. Storms

Theses and Dissertations

This research effort examines inertial navigation system aiding using magnetic field intensity data and a Kalman filter in an indoor environment. Many current aiding methods do not work well in an indoor environment, like aiding using the Global Positioning System. The method presented in this research uses magnetic field intensity data from a three-axis magnetometer in order to estimate position using a maximum – likelihood approach. The position measurements are then combined with a motion model using a Kalman filter. The magnetic field navigation algorithm is tested using a combination of simulated and real measurements. These tests are conducted using …

Bartja Dhe Shpërndarja E Energjisë Elektrike Në Republikën E Kosovës, Berat Bajrami

Theses and Dissertations

Sektori i energjisë elektrike si një ndër sektorët më të rëndësishëm industrial në ekonominë e Kosovës, duhet të planifikohet dhe zhvillohet në mënyrë adekuate dhe në kohë. Rrjeti i bartjes dhe shpërndarjes luan rol të rëndësishëm në sistemin elektroenergjetik duke bërë të mundur bartjen dhe shpërndarjen e sasive të mëdha të energjisë elektrike nga gjeneratorët vendor dhe nga importet, deri te konsumatorët e mëdhenj dhe nyjet shpërndarëse. Zhvillimi i shoqërisë dhe ngritja e varësisë për energjinë elektrike kërkon rrjet të bartjes dhe shpërndarjes të sigurt, të besueshëm dhe efikas. Varësia në rritje për energji elektrike nënkupton që toleranca për ndërprerje …

Gjenerimi I Energjisë Elektrike Përmes Paneleve Fotovoltaike Të Lidhur Në Rrjetin Elektrik Shpërndarës, Agon Abazi

Theses and Dissertations

Energjia diellore është një nga burimet për perfitimin e energjisë elektrike, duke e pare gjithnje në rritje të konsumit dhe nevojen për energji elektrike, u deshtë të merren hapa konkret dhe investime të mëdha në këtë drejtim për përfitimin e energjisë elektrike nga energjia e riperteritshme qoftë nga dielli, energjia e erës dhe burime të tjera, duke e konsideru që me energji të riperteritshme nuk ka emetim dhe ndotje të ambientit. Nxitur nga zhvillimet e fundit teknologjike dhe shqetësimi në rritje për qëndrueshmërin dhe ndikimin mjedisor të përdorimit të karburantit konvencional, mundësia për të prodhuar energji të pastër dhe të …

Dimensionimi I Mbajtësit Linear Të Tipit Kapriatë, Misim Bela

Theses and Dissertations

Në këtë temë do të flasim për konstruksionet metalike, në veçanti për konstruksionet kapriatë të cilat janë të ndërtuara prej çeliku. Janë përshkruar karakteristikat e tyre, përdorimi i tyre, vetitë dhe tipet e konstruktimit, projektimi dhe dimensionimi i konstruksioneve metalike. Janë përshkruar edhe llojet e kapriatave, karakteristikat e tyre duke u bazuar në llojin e kapriatës në të cilat rolë shumë të rëndësishën luan hapësira e cila duhet të mbulohet në bazë të cilës përcaktohet lloji i kapriatës. Detyra kryesore e këtij punimi është projektimi i një kapriatë duke pasur parasysh hapësirën që do të mbulohet, llojet e ngarkesave, klasën …

Sanimi I Pjeseve Te Asfaltit Ne Temperatur E Te Ulet Te Dimirit, Gjyljeta Kabashi

Theses and Dissertations

Kërkesat e komunikacionit rrugor për rrugët e ndërtuara dhe të përshtatura ndaj kushteve për makinat e shpejta dhe të rënda motorike,me nivele më të mëdha shërbimi ,shkallë sigurie dhe qëndrueshmëri të planifikuar,si dhe hulumtimet e deritanishme eksperimentale në fushën e teknologjisë për prodhimin e asfaltit. Në katër dekadat e kaluara kishin dhe akoma kanë ndikim të konsiderueshëm në përmirësimin e koncepteve për projektimin dhe ndërtimin e rrugëve dhe aeroporteve, sidomos të konstruksioneve fleksibile rrugore.

Ndryshimet e tilla janë pasojë e zhvillimit dhe përkryerjes së prodhimit të mjeteve lidhëse nga bitumet rrugore të fituara gjatë proceseve të rafinimit te naftës në …

Organizimi Në Ndërtimtari, Rexhep Olluri

Theses and Dissertations

Ndërtimtaria është veprimtari specifike ekonomike që ka për synim ngritjen dhe rikonstruktimin e objekteve ndërtimore. Si veprimtari, ajo realizon produktin e caktuar, objektin ndertimor-arkitektonik. Ndërtimtaria veqohet për shkak të aktiviteteve të shumta që nevojiten për arritjen e një rezultati brenda një afati kohor. Secili aktivitet si proces teknologjik ka kohëzgjatjen e tij.

Varësisht nga natyra e projektit kemi:

• Aktivitete që kryhen në vartësi nga aktivitetet tjera paraprake
• Aktivitete të pavarura, që kryhen në të njejtën kohë me aktivitet tjera.

Planifikimi dhe strukturimi i aktiviteteve punuese në varësi të kohës quhet plan dinamik i punës. Paraqitja e aktiviteteve dhe kohëzgjatjes së …

The Sap Link: A Controller Architecture For Secure Industrial Control Systems, Matthew Cody Wyman

Theses and Dissertations

Industrial Control Systems are essential to modern life. They are utilized in hundreds of processes including power distribution, water treatment, manufacturing, traffic management, and amusement park ride control. These systems are an essential part of modern life and if compromised, could result in significant economic loss, safety impacts, damage to the environment, and even loss of life. Unfortunately, many of these systems are not properly secured from a cyber attack. It is likely that a well-funded and motivated attack from a nation-state will successfully compromise an industrial control system's network. As cyber war becomes more prevalent, it is becoming more …

A Study Of Catalytic Microcombustion For A Portable Power Supply Device, Bhanuprakash Reddy Guggilla

Theses and Dissertations

The essential need for portable and dense power sources has been greatly increased with the prevalence of portable electronic devices in the past decade. Catalytic combustion of hydrocarbon and oxygenated fuels has the potential to provide an alternative power source for portable electronic devices by replacing relatively today's heavy battery technology. A successful self-ignition and sustainable catalyst combustion for a variety of fuels using Platinum (Pt)-impregnated substrate was demonstrated in our previous work.

Present work explores the performance of a microcombustion thermoelectric coupled (MTC) device with improved reactor configuration design. Chemically synthesized platinum nanoparticles with particle diameters of approx. 8 …

Masat Dhe Veprimet Për Parandalimin Dhe Menaxhimin E Rreziqeve Në Kantier Ndërtimi - Rasti Studimor N.N.Sh “Labi Gipser”- Deçan, Fatmir Ahmetxhekaj

Theses and Dissertations

Sektori i ndërtimit mbetet mjaft sfidues dhe me rrezik të lartë edhe pse viteve të fundit ka pasur një rritje të lehtë për sa i takon rregullimit juridik dhe ndërmarrjes së masave për menaxhimin e tij. Megjithatë, ndërrmarrja e masave dhe menaxhimi i rrezikut mbetet ende larg normave dhe standardeve për siguri dhe mbrojtje në punë. Mbështetur në statistika të deklaruara nga agjencioni i statistikave të Kosovës, inspektorati i punës në Republikën e Kosovës, si dhe burime tjera të shkruara dhe elektronike rezulton se rastet e lendimeve dhe atyre me fatalitet në sektorin e ndërtimit po tregojnë rritje të lehtë …

Secure State Estimation In The Presence Of False Information Injection Attacks, Maitham Alsalman

Theses and Dissertations

In this dissertation, we first investigate the problem of source location estimation in wireless sensor networks (WSNs) based on quantized data in the presence of false information attacks. Using a Gaussian mixture to model the possible attacks, we develop a maximum likelihood estimator (MLE) to estimate the source location. The Cramer-Rao lower bound (CRLB) for this estimation problem is also derived.

Then, the assumption that the fusion center does not have the knowledge of the attack probability and the attack noise power investigated. We assume that the attack probability and power are random variables which follow certain uniform distributions. We …

Capillary Forces In Partially Saturated Thin Fibrous Media, Ali Moghadam

Theses and Dissertations

Capillarity is often exploited in self-cleaning, drag reducing and fluid absorption/storage (sanitary products) purposes just to name a few. Formulating the underlying physics of capillarity helps future design and development of optimized structures. This work reports on developing computational models to quantify the capillary pressure and capillary forces on the fibrous surfaces. To this end, the current study utilizes a novel mass-spring-damper approach to incorporate the mechanical properties of the fibers in generating virtual fibrous structures that can best represent fibrous membranes. Such virtual fibrous structures are then subjected to a pressure estimation model, developed for the first time in …

Engineering Magnetic Properties Of Nanoparticles For Biomedical Applications And Magnetic Thin Film Composite Heterostructures For Device Applications., Shivakumar Hunagund

Theses and Dissertations

The motivation of this study is to investigate the size dependent properties of Gadolinium silicide nanoparticles and their potential applications in Biomedicine. We use two approaches in our investigation - size dependence and possible exchange interaction in a core-shell structure. Past results showed Gd₅Si₄ NPs exhibit significantly reduced echo time compared to superparamagnetic iron oxide nanoparticles (SPION) when measured in a 7 T magnetic resonance imaging (MRI) system. This indicates potential use of Gd₅Si₄ ferromagnetic nanoparticles as T2 contrast agents for MRI.

Until recently most contrast agents (CA) that are used in Magnetic Resonance …

The Evaluation Of An Android Permission Management System Based On Crowdsourcing, Pulkit Rustgi

Theses and Dissertations

Mobile and web application security, particularly concerning the area of data privacy, has received much attention from the public in recent years. Most applications are installed without disclosing full information to users and clearly stating what they have access to. This often raises concerns when users become aware of unnecessary information being collected or stored. Unfortunately, most users have little to no technical knowledge in regard to what permissions should be granted and can only rely on their intuition and past experiences to make relatively uninformed decisions. DroidNet, a crowdsource based Android recommendation tool and framework, is a proposed avenue …