Engineering Commons^™

Study Of Latent Heat Thermal Energy Storage Systems For Concentrated Solar Power Plants, Hermes Chirino

Theses and Dissertations

Concentrated Solar Power (CSP) using phase change material (PCM) as the storage medium in the Thermal Energy Storage (TES) system is a promising technology for large scale utilization of solar thermal energy because heat latent heat thermal energy storage (LHTES) systems can store more energy as the latent heat during the melting process.

This study analyzes the different dimensionless parameters from the 1-D transient enthalpy-based mathematical model used to simulate the heat transfer and flow within the LHTES system. These dimensionless parameters are varied and analyzed with the main objective of increasing thermal energy storage efficiency and exergy efficiency of …

Effect Of Processing Parameters On The Electrochemical Performance Of Forcespun Metal Oxide/Carbon Composite Fibers For Li-Ion Batteries, Howard A. Campos

Theses and Dissertations

Metal oxides have been gaining interest as electrode materials for rechargeable Li-ion batteries due to various properties including low cost, low toxicity, and high theoretical capacity. In this research work the effect of two different metal oxide/carbon fiber composites, Fe3O4/C and ZnO/C, on the electrochemical performance for Li-ion batteries will be explored. This is also the first time that results are reported, to the best of our knowledge, of these fiber composites through the Forcespinning ® method. Scanning electron microscopy (SEM), Energy-Dispersive X-ray Analysis (EDS), X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (XRD), and electrochemical analysis were used to investigate …

Security Evaluation Of Virtualized Computing Platforms, Ganesh Reddy Gunnam

Theses and Dissertations

In this thesis, security experiments were conducted to evaluate embedded security protocol performance of two leading server operating systems, Apple’s MAC OS server LION Vs. Microsoft’s Windows server 2012 R2 OS under different types of security attack. Furthermore, experiments were conducted to understand and evaluate the effect of virtualization using Hyper-V with Windows 2012 R2 OS on MAC hardware platform. For these experiments, connection rate, connection latency, non-paged pool allocations and processor core utilization for different OS, virtual machines, and under different traffic types were measured.

The Psychological Health Of Airline Pilots: A Flight Deck Crew’S Perceptions And Willingness To Fly, Jason Charles Herkimer

Theses and Dissertations

Pilots have an image of bravado and charisma which includes that of a hardened, unemotional professional. What happens when the inevitable hardship occurs to a pilot? In the past, physical attributes were highly sought after in the recruitment of pilots. Eventually, pilots can and will suffer from the same psychological stressors as the general population. The purpose of this study is to determine the effect stigmatizing attitudes and psychological treatment of pilots have on a flight deck crew’s willingness to fly. The current study incorporated several different methodologies including a between subjects true experimental, an analysis of covariance (ANCOVA), an …

System Study Of An On-Orbit Additive Manufacturing Cubesat, Juliette Isabelle Bido

Theses and Dissertations

The AddCube mission aims to demonstrate additive manufacturing technology in microgravity on a CubeSat platform by 3D-printing a 1-meter long rectangular beam on orbit. To accomplish this task, Made In Space Inc. (MIS) will provide the Extended Structure Additive Manufacturing Machine – CubeSat (ESAMM-C) payload. The high power required by the ESAMM-C payload creates a complex thermal problem within the spacecraft due to tight volume constraints associated with CubeSats. To cope with this problem, an in depth worst-case thermal analysis of the integrated spacecraft is conducted and an appropriate thermal management system for the mission is designed. Temperature regulation is …

Flight Testing Angle-Of-Attack Warning Combinations On Part 23 Aircraft, Jennifer Grey Geehan

Theses and Dissertations

The high number of accidents involving General Aviation (GA) aircraft leads to a need for improved methods to warn pilots of high angles of attack (AOA) and impending stall. Such methods must be certified by the Federal Aviation Administration (FAA) under Federal Aviation Regulations Part 23 regarding their effectiveness in preventing departures from controlled flight. Therefore, methods of compliance must be developed to certify Part 23 aircraft equipped with AOA warning or limiting systems. The research objectives were to (a) determine methods for the evaluation of AOA warning and limiting systems and to (b) evaluate the effectiveness of baseline combinations …

Sensitivity Of Facial Organs Of Pythons As Deduced By Radiation Heat Transfer Analysis Under Varying Environmental Conditions, Rama Wairagkar

Theses and Dissertations

Predicting the behavior of snakes has been an interest to several scientists for the last few decades. Even though considerable amount of research has been carried out pertaining to snakes, there remains a degree of curiosity regarding their striking ability, live prey detection at locations where visual clues are unobtainable, thermosensation and the phenomena that drives these conducts. Researches carried out so far have moderately disregarded the perception of sensitivity of facial pits of snakes and its characteristics under contrasting temperature domains. This thesis attempts to undertake a computational analysis of the sensitivity of facial pits of Burmese pythons under …

A Heuristic Method For The Determination Of Assembly Network And Line Design For Discrete Manufacturing Processes, Ismael Hernan Naranjo Velez

Theses and Dissertations

This paper presents with a proposed alternative precedence algorithm which is determined by the Solid surfaces of the product design. The representation address in this paper address the manufacturing planning from all manufacturing levels of the product. Sequence is introduce to this paper in order to proof the propose precedence network alternatives. Both manufacturing level solutions are heuristic. This thesis explores the connection of the precedence and the sequence, as it introduces physical manufacturing constraints and its relationships to the station process planning. Precedence network are usually determine by the designer principal point and assembled connections. The proposed algorithm avoids …

Model Based Systems Engineering High Level Design Of A Sustainable Electric Vehicle Charging And Swapping Station Using Discrete Event Simulation, Obinna Henry Ginigeme

Theses and Dissertations

In line with the spate of technological advances, the transportation industry has also witnessed an increase in the adoption of Electric Vehicles (E.Vs). However, there has been and are still some underlying negating factors to the wide spread acceptance of these electric vehicles; one of note is the unavailability and inaccessibility of adequate charging infrastructure, long charging times, limited driving ranges, costs of the vehicles etc. These and many more characteristics lead to a trend popularly known as “range anxiety”. One of the major strengths of electric vehicles are their ability to be powered by electric energy via stored chemical …

Towards Green Building: Energy Efficient Roof System For Buildings, Dhruv Sangal

Theses and Dissertations

The present work focusses on investigating the thermal performance of different energy efficient roof systems for buildings for different climates. Buildings constitutes about 40 percent of total energy consumed by United States, and previous research shows that 20 percent of the building cooling load comes through ceiling of a building. Thus, it is important to analyze different energy efficient roof systems which can help in reducing building cooling and heating load. The present study focusses on three technologies – green roof, radiant barriers and photovoltaics. To analyze the performance of these systems, a detailed energy based mathematical model were developed …

Temporal Transformation Of Barrier Islands A Round Nakdong Estuary, Sukzun Youn

Theses and Dissertations

The Nakdong Estuary system near Busan, South Korea consists of dynamic shorelines characterized by morphological transformations that result from both natural disasters (typhoons and flooding) and construction projects (Nakdong Estuary Dam, gates in the West Nakdong River and Busan New-ports). This study aims to synthesize existing data for tides, waves, bathymetry and meteorological data obtained from a variety of institutions with the objectives of (1) identifying and ranking major factors that influence morphological transformations and (2) determining how these factors influence morphological change over time. These objectives were met by analyzing patterns of flow and sediment transport using Center Point …

An Analysis Of The Size And Impact Of Digital Footprints, Whitney Nielsen Maxwell

Theses and Dissertations

Personal information available online is known as a digital footprint. While many have a digital footprint, few if any, know what it encapsulates or how to control it. Technology and personal information are becoming more intertwined as technology becomes more integrated with everyday activities. Personal information can be defined as details that apply to a person such as race or shopping habits. Shopping habits are considered personal information by many corporations who spend money to track, or even predict purchases of individuals, whereas more traditional forms of personal information are details like gender, birthdate, and home town. With a wide …

Project Management: Skills, Tools, And Knowledge Construction Professionals Consider Important For Keeping Projects On Schedule, Lyle Scott Davies

Theses and Dissertations

Project managers have a major role in the construction and completion of projects. Much of their work consists of reviewing, clarifying, and coordinating information required by the field management and subcontractors performing the work on the job site. The assistance they give with the transfer of information helps with successfully completing projects. For many people, the largest indicator that a project was successful is that construction activities were completed on schedule. While finishing on schedule may be the primary focus of those involved with construction activities, projects still struggle to finish on time. The purpose of this study is to …

Advancements In Radio Astronomical Array Processing: Digital Back End Development And Interferometric Array Interference Mitigation, Mitchell Costus Burnett

Theses and Dissertations

The Brigham Young University (BYU) Radio Astronomy Systems group, in collaboration with the National Radio Astronomy Observatory (NRAO), the Center for Astrophysics at West Virginia University (WVU), and the Green Bank Observatory (GBO) have developed, and commissioned, a broadband real-time digital back end processing system for a 38-element phased array feed (PAF) with 150 MHz of instantaneous bandwidth. This system is capable of producing coarse and fine channel correlations, and implements a real-time beamformer that forms 7 simultaneous dual-polarized beams. This thesis outlines the hardware and software development for the digital back end and presents on-telescope commissioning results. This system …

Investigating If Multidisciplinary Or Homogenous Teams Are More Innovative In A Higher Education Setting, Blake Howard Hoover

Theses and Dissertations

This study is derived from the claim that multidisciplinary groups are more innovative than homogeneous groups; a claim that has flooded the business industry and has become criteria for accreditation in higher education. However, the impact of disciplinary diversity in work groups is a growing area of research; therefore, it is yet to be thoroughly understood. The purpose of this study is to answer the question: are multidisciplinary teams more innovative than homogenous teams. To accomplish this university students from differing majors were sorted into multidisciplinary and homogeneous groups while participating in a two-day innovation course. The course taught the …

Analysis Of Safety Impacts Of Access Management Alternatives Using The Surrogate Safety Assessment Model, Kyung Min Kim

Theses and Dissertations

In a traditional safety impact analysis, it is necessary to have crash data on existing roadway conditions in the field and a few years must pass before accumulating reliable crash data. This is a time-consuming approach and there remains uncertainty in the crash data due to the random nature of crash occurrences. The Surrogate Safety Assessment Model (SSAM) was developed for resolving these issues. With SSAM, a conflict analysis is performed in a simulated environment. A planned improvement alternative under study is modeled and no physical installation of the alternative is needed. Hence, the method using a simulation software along …

Tribopairs In Wellbore Drilling: A Study Of Pcd Tilting Pad Bearings In An Electric Submersible Pump, Cameron B. Ellis

Theses and Dissertations

A polycrystalline diamond was tested as a bearing material for a tilting pad thrust bearing to be used in an electric submersible pump, which elevates process fluids from the bottom of well bores. The goal of this study was to compare the PCD to a current best of technology, which is stainless steel with an engineering polymer.This study found that PCD can handle larger loads than current technology but is limited in size due to diamond sintering and manufacturing constraints. The maximum size is Ø75mm.

An Investigation Of Elementary Teachers<'> Self-Efficacy For And Beliefs About The Importance Of Engineering Education, Khristen Lee Massic

Theses and Dissertations

In order for the United States to regain its global standing in science and engineering, educational and governmental organizations have started to re-emphasize science, technology, engineering, and math content in k-12 classrooms.While some preliminary research has been conducted on student and teacher perceptions related to engineering, there has been little research conducted related to teachers beliefs about the importance of engineering content in their classrooms and relatively few studies have investigated elementary teachers teaching engineering self-efficacy. Current studies have investigated the impact of professional development on teachers teaching engineering self-efficacy but these studies were conducted with limited sample sizes, for …

An Obstacle Avoidance System For The Visually Impaired Using 3-D Point Cloud Processing, Evan Justin Taylor

Theses and Dissertations

The long white cane offers many benefits for the blind and visually impaired. Still, many report being injured both indoors and outdoors while using the long white cane. One frequent cause of injury is due to the fact that the long white cane cannot detect obstacles above the waist of the user. This thesis presents a system that attempts to augment the capabilities of the long white cane by sensing the environment around the user, creating a map of obstacles within the environment, and providing simple haptic feedback to the user. The proposed augmented cane system uses the Asus Xtion …

Characterization Of Mechanical Properties Of Battery Electrode Films From Acoustic Resonance Measurements, Kathryn Lanae Dallon

Theses and Dissertations

Measurements of the mechanical properties of lithium-ion battery electrode films can be used to quantify and improve manufacturing processes and to predict the mechanical and electrochemical performance of the battery. This thesis demonstrates the use of acoustic resonances to distinguish among commercial-grade battery films with different active electrode materials, thicknesses, and densities. Resonances are excited in a clamped circular area of the film using a pulsed infrared laser or speaker and responses are measured using an electret condenser microphone. A numerical model is used to quantify the sensitivity of resonances to changes in mechanical properties. When the numerical model is …

A Comparison Between Self-Cleaning Properties Via Rolling Droplets And Condensation On Superhyrophobic Surfaces, David Leland Miller

Theses and Dissertations

Superhydrophobic (SH) surfaces are super water repellent surfaces on which a droplet of water will bead up like a marble and roll off the surface with minimal tilting of the surface. This is caused by the combination of a hydrophobic coating and a rough surface structure. To achieve thermodynamic stability, surface tension of the water pulls the droplet into this shape to minimize the contact area between the droplet and the surface. This creates a high contact angle (CA) between the droplet and the surface and a low sliding angle (SA) of which the droplet begins to roll off the …

Microstructural Evaluation Of Hydrogen Embrittlement And Successive Recovery In Advanced High Strength Steel, Quentin Scott Allen

Theses and Dissertations

Advanced high strength steels (AHSS) have high susceptibility to hydrogen embrittlement, and are often exposed to hydrogen environments in processing. In order to study the embrittlement and recovery of steel, tensile tests were conducted on two different types of AHSS over time after hydrogen charging. Concentration measurements and hydrogen microprinting were carried out at the same time steps to visualize the hydrogen behavior during recovery. The diffusible hydrogen concentration was found to decay exponentially, and equations were found for the two types of steel. Hydrogen concentration decay rates were calculated to be -0.355 /hr in TBF steel, and -0.225 /hr …

Phased-Array Feed Instrumentation And Processing For Astronomical Detection, Interference Mitigation, And Transient Parameter Estimation, Richard Allen Black

Theses and Dissertations

Radio astronomy, the survey and study of naturally occurring astronomical radio signals, is a challenging field in terms of engineering requirements. The typical astronomical signal of interest is incredibly faint, resulting in very low signal-to-noise ratios (SNRs) on the order of -30 dB or lower. To detect such signals, one must have an uncommonly low and stable receiver noise temperature, high gain through large aperture reflectors, and state-of-the-art signal processing algorithms. One must also be able to mitigate the effects of interference, the presence of which, even if extremely weak, can completely mask the faint astronomical signals of interest. To …

Current State Of Practice Associated With The Use Of Building Information Modeling (Bim) In The Custom Home Building Industry, William Noble Smith

Theses and Dissertations

Building Information Modeling (BIM) has entered the construction industry and has permeated the commercial sector. Research is continually performed to expand the capabilities and applications within the industry. However, research has historically been mostly limited to the commercial sector and has seen little expansion to other sectors of the industry including the residential sector. The potential cause for this may be the limited number of industry professionals who utilize the software to the benefit of their companies. The focus of this study was specifically the custom home building sector of residential construction in the United States because of the unique …

A Molecular Simulation Study Of Antibody-Antigen Interactions On Surfaces For The Rational Design Of Next-Generation Antibody Microarrays, Derek B. Bush

Theses and Dissertations

Antibody microarrays constitute a next-generation sensing platform that has the potential to revolutionize the way that molecular detection is conducted in many scientific fields. Unfortunately, current technologies have not found mainstream use because of reliability problems that undermine trust in their results. Although several factors are involved, it is believed that undesirable protein interactions with the array surface are a fundamental source of problems where little detail about the molecular-level biophysics are known. A better understanding of antibody stability and antibody-antigen binding on the array surface is needed to improve microarray technology. Despite the availability of many laboratory methods for …

Improving Thermodynamic Consistency Among Vapor Pressure, Heat Of Vaporization, And Liquid And Ideal Gas Heat Capacities, Joseph Wallace Hogge

Theses and Dissertations

Vapor pressure (P_vap), heat of vaporization (ΔH_vap), liquid heat capacity (C_p^l), and ideal gas heat capacity (C_p^ig) are important properties for process design and optimization. This work focuses on improving the thermodynamic consistency and accuracy of the aforementioned properties since these can drastically affect the reliability, safety, and profitability of chemical processes. They can be measured for pure organic compounds from the triple point, through the normal boiling point, and up to the critical point. Additionally, ΔH_vap is proportional to the derivative of vapor …

Multiple Target Tracking In Realistic Environments Using Recursive-Ransac In A Data Fusion Framework, Jeffrey Dyke Millard

Theses and Dissertations

Reliable track continuity is an important characteristic of multiple target tracking (MTT) algorithms. In the specific case of visually tracking multiple ground targets from an aerial platform, challenges arise due to realistic operating environments such as video compression artifacts, unmodeled camera vibration, and general imperfections in the target detection algorithm. Some popular visual detection techniques include Kanade-Lucas-Tomasi (KLT)-based motion detection, difference imaging, and object feature matching. Each of these algorithmic detectors has fundamental limitations in regard to providing consistent measurements. In this thesis we present a scalable detection framework that simultaneously leverages multiple measurement sources. We present the recursive random …

Reliability Of Feqdrain For Modeling Performance Of Sand Treated With Large-Diameter Prefabricated Drains For Liquefaction Mitigation, Travis Hatch Meservy

Theses and Dissertations

Finite element modeling of laminar shear box testing that consisted of loose sand treated with large diameter prefabricated vertical drains (PVDs), was performed. The objective of the modeling was to evaluate the reliability of the computer program FEQDrain for predicting excess pore pressure ratios (Ru) at sites treated with prefabricated drains. FEQDrain was found to be capable of successfully modeling measured excess pore pressure ratio time histories from the laminar shear box experiment, as long as an appropriate combination of €˜number of equivalent cycles and €˜shaking duration was chosen, and sensitive parameters were in the range of measured values. Hydraulic …

Eigenblades: Application Of Computer Vision And Machine Learning For Mode Shape Identification, Alex W. La

Theses and Dissertations

On August 27, 2016, Southwest Airlines flight 3472 from New Orleans to Orlando had to perform an emergency landing when a fan blade separated from the engine hub and destroyed the cowling and punctured the fuselage. Initial findings from the metallurgical examination conducted in the National Transpiration Safety Board Materials Laboratory found that the fracture surface of the missing blade showed curving crack arrest lines consistent with fatigue crack growth. Fatigue is often cause by resonate vibrations. Modal analysis is a method that can model the natural frequencies and bending modes of turbomachinery blades. When performing modal analysis with finite …

Managed Containers For Increased Cyber-Resilience, Xavier J. Merino Aguilera

Theses and Dissertations

Traditional defense mechanisms are no longer adequate in protecting critical infrastructure and mission critical systems. These systems require to be always-on-always-connected. High availability and data integrity become crucial to deliver their mission. Unable to guarantee uncompromisable security and given that systems will inevitably be attacked, we must change our goals to guarantee mission survivability, the ability of the system to fight through the attack. Previous work has been done to increase availability and integrity using virtual machines. We move away from virtual machines towards Linux containers and implement resiliency strategies to guarantee stateful system recovery after an attack. The goal …