Engineering Commons^™

Traffic Sign Management: Data Integration And Analysis Methods For Mobile Lidar And Digital Photolog Big Data, Majid Khalilikhah

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Traffic signs often convey critical information to drivers. However, traffic signs are only effective when clearly visible and legible. This study aims to determine the effects of various damage and deterioration forms on sign retroreflectivity, identify the most important factors affecting traffic sign visual condition, predict traffic sign vandalism that obstructs critical messages to drivers, and identify important environmental factors contributing to the temporary obstruction of the sign messages. To do so, two data sets are used. A sample data of over 1,700 signs was manually collected in the field, and the background retroreflectivity of each sign was measured using …

Rudder Augmented Trajectory Correction For Unmanned Aerial Vehicles To Decrease Lateral Image Errors Of Fixed Camera Payloads, Thomas M. Fisher

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

When using small unmanned aerial vehicles (UAVs) with cameras onboard for ground surveying, two competing problems arise. First is the desire to keep the camera sensor parallel with the ground and second is to maintain the proper flight path. When the cameras are physically fixed to the UAV and as the plane banks to maintain the desired path, the camera sensor is no longer kept parallel with the ground. This thesis focuses on a method called rudder augmented trajectory correction that allows for flat turns instead of banking the aircraft. Because of this, the camera is able to stay parallel …

Low-Temperature Aqueous Corrosion Behavior Of Uranium Molybdenum Alloys, Levi D. Gardner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nuclear fuel characterization requires understanding of the various conditions to which materials are exposed in-reactor. One of these important conditions is corrosion, particularly that of fuel constituents. Therefore, corrosion behavior is of special interest and an essential part of nuclear materials characterization efforts. In support of the Office of Material Management and Minimization’s Reactor Conversion Program, monolithic uranium-10 wt% molybdenum alloy (UMo) is being investigated as a low enriched uranium alternative to highly enriched uranium dispersion fuel currently used in domestic high performance research reactors. The aqueous corrosion behavior of U-Mo is being examined at Pacific Northwest National Laboratory (PNNL) …

The Effects Of Meter Orientation Downstream Of A Short Radius Elbow On Electromagnetic Flow Meters, Jared C. Justensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Electromagnetic flowmeters (known as magnetic flow meters) are a widely used type of flowmeter. The accuracy of magnetic flow meters are a function of several factors, not the least of which is the flow condition inside the pipe. It has been shown that disturbances in the velocity profile affects the accuracy of a magnetic flow meter (Luntta, 1998). Accordingly, manufacturers of magnetic flow meters give installation guidelines. These guidelines help prevent the user from installing the meter in a pipe configuration that is likely to cause the meter to produce inaccurate results. Although most manufacturers provide recommendations about the amount …

Developing A Method For Quantifying Nitrogen Transformation Rates Using In Situ Benthic Chambers Dosed With Isotopically Labeled Nitrate, Chelsea A. Stewardson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nitrogen, a nutrient required for biological growth, is a common water quality parameter of concern as too much nitrogen can cause a strain on aquatic environments and even death of plants and animals. One way high levels of nitrogen are introduced into aquatic systems is by anthropogenic sources such as effluent from water reclamation facilities. A method was designed to observe the fate of nitrogen and measure the rates of its transformation into different nitrogen species within a stream receiving the effluent from the Silver Creek Water Reclamation Facility in Park City, Utah.

Sealed chambers were designed and installed along …

Application Of Computational Fluid Dynamics In Flow Measurement And Meter Design, Zachary B. Sharp

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Flow measurement has been an important part of society for hundreds of years. For this reason there are many methods to measure flow rates both in open channel scenarios like irrigation canals and also in closed conduits like pipelines that supply water for human use. This research focused on Venturi flow meters which have been used to measure flow since the 1890’s. The object of this research was to use computational fluid dynamics and laboratory data to provide industry with applicable answers to some under researched areas in flow measurement. The areas chosen for this research include areas requested by …

The Application Of Unmanned Aerial Vehicle To Precision Agriculture: Chlorophyll, Nitrogen, And Evapotranspiration Estimation, Manal Elarab

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Precision agriculture (PA) is an integration of a set of technologies aiming to improve productivity and profitability while sustaining the quality of the surrounding environment. It is a process that vastly relies on high-resolution information to enable greater precision in the management of inputs to production. This dissertation explores the usage of multispectral high resolution aerial imagery acquired by an unmanned aerial systems (UAS) platform to estimate three fundamental crop parameters (plant chlorophyll, leaf nitrogen and crop water demand). The UAS acquired imagery in the visual, near infrared and thermal infrared spectra with a resolution of less than a meter …

Micro-Ct Inspection Of Impact Damage In Carbon/Epoxy Rods, Lindsey Charlene Cahoon

Theses and Dissertations

Various configurations of unidirectional carbon/epoxy composite rods were impacted radially, inspected using micro-CT scanning equipment, and tested in axial compression to measure the residual strength after impact. This data was used to correlate the relationship between impact energy, residual strength, and the peak crack area and total crack volume along the length of the specimens. These specimens represent local members of open three-dimensional composite lattice structures (e.g., based on isogrid or IsoTruss® geometries) that are continuously fabricated using advanced three-dimensional braiding techniques. The specimens were radially impacted with 2.5 J (1.9 ft-lbs), 5.0 J (3.7 ft-lbs), 7.5 J (5.6 ft-lbs), …

Computing Research In Academia: Classifications, Keywords, Perceptions, And Connections, Sung Han Kim

Theses and Dissertations

The Association for Computing Machinery (ACM) recognizes five computing disciplines: Computer Science (CS), Computer Engineering (CE), Information Technology (IT), Information Systems (IS), and Software Engineering (SE). Founded in 1947 the ACM is the world's largest society for computing educators, researchers, and professionals. While Computer Science has been a degree program since 1962, the other four are relatively new. This research focuses on understanding the graduate research in four of the five ACM disciplines (CS, CE, IT, and IS) using a large body of thesis and dissertation metadata. SE is not found in the metadata and graduate work in SE is …

Roadway Safety Analysis Methodology, Samuel Thomas Mineer

Theses and Dissertations

The Utah Department of Transportation (UDOT) Traffic and Safety Division continues to advance the safety of the state roadway network through network screening and decision making tools. In an effort to aid UDOT in meeting this goal, the Department of Civil and Environmental Engineering at Brigham Young University (BYU) has worked with the Statistics Department in developing analysis tools for highway safety, specifically the Utah Crash Prediction Model (UCPM) and the Utah Crash Severity Model (UCSM). Additional tools and methodologies, such as the "Hot Spot Identification and Analysis," have been created to summarize the roadway characteristics, crash data, and possible …

Implementation Of Bim In The Municipal Plan Review Process, Liz Shantalle Ricardo Belliard

Theses and Dissertations

Obtaining a building permit is an important step for any construction project. Whether it is for a new construction or a remodel job, the process involves a plan review performed by building officials. The purpose of this research was to explore ways in which Building Information Modeling (BIM) could be used to aid code officials during the plan review process. The objectives of the study were to determine if the level of detail in BIM was complete enough to allow a plan review to be perform accurately, to identify the extent to which architects are comfortable with using their models …

High-Pressure Properties Of Several Narrow Bandgap Semiconductors From First-Principles Calculations, Andrew Michael Alvarado

UNLV Theses, Dissertations, Professional Papers, and Capstones

The electronic, thermodynamic, and structural properties of three semiconducting materials, ZnO, InN, and PbS, at high pressure are investigated utilizing first-principles calculations based on density function theory. The first two systems, ZnO and InN, crystalize as hexagonal structures at ambient conditions and transition to a cubic structure at higher pressures. The last system, PbS, is cubic at ambient conditions, but transitions to an orthorhombic structure at higher pressure. At ambient conditions, these materials are well known semiconductors with vast amount of research and a variety of wide ranging applications in electrical devices. However, there is a lack of understanding of …

On The Scattering Of An Acoustic Plane Wave By A Soft Prolate Spheroid, Joseph Michael Borromeo

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis solves the scattering problem in which an acoustic plane wave of propagation number K1 is scattered by a soft prolate spheroid. The interior field of the scatterer is characterized by a propagation number K2, while the field radiated by the scatterer is characterized by the propagation number K3. The three fields and their normal derivatives satisfy boundary conditions at the surface of the scatterer. These boundary conditions involve six complex parameters depending on the propagation numbers. The scattered wave also satisfies the Sommerfeld radiation condition at infinity. Through analytical methods, series representations are constructed for the interior field …

Efficient Algorithms For Clustering Polygonal Obstacles, Sabbir Kumar Manandhar

UNLV Theses, Dissertations, Professional Papers, and Capstones

Clustering a set of points in Euclidean space is a well-known problem having applications in pattern recognition, document image analysis, big-data analytics, and robotics. While there are a lot of research publications for clustering point objects, only a few articles have been reported for clustering a given distribution of obstacles. In this thesis we examine the development of efficient algorithms for clustering a given set of convex obstacles in the 2D plane. One of the methods presented in this work uses a Voronoi diagram to extract obstacle clusters. We also consider the implementation issues of point/obstacle clustering algorithms.

Ozonation In Water Reuse: Formation And Mitigation Of N-~Nitrosodimethylamine, Erica J. Marti

UNLV Theses, Dissertations, Professional Papers, and Capstones

Formation of N-nitrosodimethylamine (NDMA) is a substantial concern for drinking water and water reuse. NDMA, a probable human carcinogen, is formed when water is disinfected with chloramines and ozone. This research focused on three issues regarding NDMA formation and mitigation. The first issue involved understanding the compounds (i.e., precursors) present in water and wastewater that react with ozone to form NDMA. Model precursors were identified and molar yields for NDMA formation were determined. The model precursors form high amounts of NDMA with ozone, but form very little NDMA with chloramines, which means there are two distinct groups of NDMA precursors: …

Causes Of Change Orders And Its Impact On Road Maintenance Contracts, Kabindra Kumar Shrestha

UNLV Theses, Dissertations, Professional Papers, and Capstones

Change orders (CO) commonly generate cost-growth, schedule-growth or both, in construction as well as in maintenance contracts. Literature reviews revealed that the causes and impact of CO on new construction contracts had been comprehensively studied, but the causes and impact of CO in maintenance contracts remained neglected. This study collected CO data on road maintenance contracts to determine the amount of CO and the most frequent and high-risk road maintenance activities that had CO. A Delphi study was conducted with 33 maintenance engineers from the state Department of Transportation (DOT) to identify causes of CO and its impact on cost …

Effects Of Radiation Heating On Additively Printed Hybrid Fuel Grain Oxidizer-To-Fuel Ratio Shift, Stephen L. Merkley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis examined the hypothesis that radiative heat transfer in small-scale printed-fuel hybrid rocket motors is responsible for the observed decreasing oxidizer-to-fuel (O/F) ratio shift. The magnitude of the radiation term was negligible for the motor sizes and types of propellants that have been previously tested, but was reintroduced in this study. To prove this hypothesis, a detailed enthalpy balance model was developed and tested using experimental fuel regression rate data obtained from a variety of motor scales using additively-manufactured acrylonitrile butadiene styrene (ABS) fuel grains.

Analyzing Irrigation District Water Productivity By Benchmarking Current Operations Using Remote Sensing And Simulation Of Alternative Water Delivery Scenarios, Jonna D. Van Opstal

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The competition for fresh water is vastly increasing particularly in semi-arid areas. Agricultural irrigation areas are urged to decrease their water use, being the largest consumer of fresh water in these areas. Improvements in irrigation management aim at increasing crop production whilst maintaining or decreasing water use. The analysis of water productivity at the irrigation district scale is challenging due to spatial heterogeneity between fields and temporal variability between growing seasons.

This dissertation makes use of satellite-based remote sensing imagery and an irrigation system simulation model to determine the water management at different spatial scales from field scale to the …

Anaerobic Digestion Process Stability And The Extension Of The Adm1 For Municipal Sludge Co-Digested With Bakery Waste, Morris Elya Demitry

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The anaerobic digestion process is used to treat and convert waste organic matter to biogas (principally methane and carbon dioxide) through biological, chemical and physical reactions. The biogas can be used as a source of energy recovery. In order to increase the biogas production rate, two different kinds of waste (municipal wastewater treatment sludge and bakery waste) were mixed together to enhance the anaerobic process and increase the biogas production in pilot scale reactors. The process succeeded in increasing biogas production and at the same time kept the process of treatment effective when high rates of organics were fed to …

Towards Alternative Pathways: Nontraditional Student Success In A Distance-Delivered, Undergraduate Engineering Transfer Program, Angela L. Minichiello

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nontraditional students, including those who delay college entry, attend college part-time, work full-time, or financially support themselves or dependents, are highly underrepresented in engineering education. Recently, the United States began emphasizing a need to access this untapped human potential. U.S. educational policymakers now seek increased nontraditional student participation in engineering education through the creation of robust new pathways—within and between 2- and 4- year institutions—to undergraduate engineering degrees.

To be impactful, alternative pathways must be grounded in knowledge related to nontraditional student success in engineering. To access this knowledge, this study qualitatively examined the experiences of 14 nontraditional students who …

Investigating Biosynthetic Steps Of An Angucycline Antifungal, S. Gabrielle Gladstone

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The species of bacterium Streptomyces sp. SCC-2136 which has the American Type Culture Collection index 55186 naturally produces two chemical compounds, labeled Sch 47554 and Sch 47555. These compounds were previously reported to posess antifungal activity. This thesis sets out to confirm the mechanism by which the bacterium produces these compounds; specifically which genes are responsible for producing the enzymes that make and shape the molecules.

The genes and enzymes that were characterized are the minimal polyketide synthase, the ketoreductase that specifically acts on the ninth carbon, the first-ring aromatase, the subsequent ring cyclase, and two oxygenases. Also elucidated …

Benchmark Experiments For Natural Convection In Nuclear Fuel Rod Bundles, Kyle L. Jones

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Buoyancy is the mechanism through which heated air causes fluid motion due to a difference in temperature between a body and the surrounding fluid. This fluid motion can be very erratic and unstable, which creates a difficult problem when attempting to simulate this fluid motion. Using high performance computational power the capability of simulating these complex interactions is available but requires assessment to determine the accuracy of these difficult flow scenarios. This study provides experimental data that can be used to assess the simulation’s accuracy and to ensure the computational models are achieving the correct solution. The Rotatable Buoyancy Tunnel …

Microalgae Sorption Of Ten Individual Heavy Metals And Their Effects On Growth And Lipid Accumulation, Eric M. Torres

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study is to determine the potential microalgae have for being a heavy metal remediation tool. Heavy metals are naturally occurring elements that can be found inside the earth or on its surface. Typically, heavy metals are found naturally at low concentrations. However, through human activities, heavy metals are continually making their way to the surface and being concentrated. This happens largely through mining and manufacturing operations. For example, NiCd batteries produce waste containing nickel and cadmium, and paper manufacturing produces waste containing high levels of lead. As underdeveloped nations continue to industrialize and the world population …

Investigating The Effect Of Capping Layers On Final Thin Film Morphology After A Dewetting Process, Benjamin C. White

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nanoparticles on a substrate have numerous applications in nanotechnology, from enhancements to solar cell efficiency to improvements in carbon nanotube growth. Producing nanoparticles in a cheap fashion with some control over size and spacing is difficult to do, but desired. This work presents a novel method for altering the size and spacing of nickel and gold nanoparticles. Dewetting is a methodology to reduce thin films to an ensemble of discrete droplets. The introduction of alumina capping layers to thin nickel films during a pulsed laser-induced dewetting process has yielded reductions in the mean and standard deviation of radii and pitch …

An Energy-Efficient Semi-Partitioned Approach For Hard Real-Time Systems With Voltage And Frequency Islands, Jesse W. Patterson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Embedded devices are computer systems with a dedicated function, such as kitchen appliances, electronic toys, phones, et cetera. Embedded devices are commonplace, and many are expected to respond to users in real-time. Such devices are often categorized as real-time embedded systems as they differ from other embedded systems in that work performed by a real-time embedded system must be scheduled such that timeliness can be provided to the user (e.g. when someone is talking on a phone, the phone needs to be able to schedule the sending and receiving of data in a timely manner such that the conversation is …

Path Following By A Quadrotor Using Virtual Target Pursuit Guidance, Abhishek Manjunath

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Missile guidance laws have been solely developed to follow and intercept a target thereby destroying or damaging it. In this research, the primary objective is to modify and adopt a missile guidance law to be used on a quadrotor to follow a virtual target. The target is termed 'virtual' as it only exists mathematically in the form of equations. The goal is to have the quadrotor successfully following the predefined path (described by the target) while maintaining a fixed distance from the virtual target. To ensure viability and assess performance, a detailed comparison with another path following law is made.

A Risk-Based Assessment Of Agricultural Water Scarcity Under Climate Change In A Semi-Arid And Snowmelt-Dominated River Basin, Hossam Moursi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Water shortage is a crucial concern in the semi-arid areas that have relatively low precipitation. Given the current situation in semi-arid areas where the water supply
already does not meet the water demand, climate change is one of the important factors that is expected to exacerbate the water shortage problem and make the situation even worse in the future. There are many indicators that prove climate change is happening, like the increasing land temperature, sea level rise and decreasing snow cover. Therefore, studying climate change impacts is a vital issue, especially its impacts on water resources systems.

In this research, …

Quadrotor Uav Path Following Using Trajectory Shaping, Parwinder Singh Mehrok

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The propose of this research is to develop a path following control law known as Trajectory Shaping. The approach is to develop a three- dimensional (3D) version of it from an existing two-dimensional (2D) model. Apart from research on this 3D control law, a multirotor unmanned aerial vehicle (UAV) platform, having four rotors and known as quadrotor is designed from the ground up for validating the concept of path following. Several pre-defined paths like the circle and figure-eight trajectories are used to apply the newly developed version of this control law. The existing 2D concept of Trajectory Shaping guidance …

Laboratory Modeling Of Piping Initiation Behavior Through Constricted Outlet, Ibrahim Ahmed Abdelmotelb Ibrahim

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Backward erosion piping is a type of internal erosion. It occurs beneath water structures as a result of seepage force. It needs two conditions to take place; 1) sufficient hydraulic head to drive the seepage force, and 2) cohesive layer overlies the sand layer and this will lead to concentration of flow. Many researches were done in the past in an attempt to predict the critical gradient. But it was just taking into account the buoyant unit weight which found in recent research that piping can occur at much lower values than was predicted. And other researches were too conservative …

Global Thermospheric Response To Geomagnetic Storms, Padmashri Suresh

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The terrestrial atmospheric region between the altitudes of 90 km and 600 km is known as the thermosphere region. The thermosphere is continuously modulated by particle emissions and magnetic fields that originate from the sun. These fields and emissions are intensified during events known as geomagnetic storms which alter the state of the thermosphere by dumping gigawatts of energy. This energy is mostly deposited in the lower thermosphere regions of 150 km and below and can potentially have hazardous repercussions on the technological assets of mankind. These storms can disrupt radio communication systems, interrupt electric power systems, threaten the safety …