Engineering Commons^™

Performance Testing And Analysis Of Synchronous Reluctance Motor Utilizing Dual-Phase Magnetic Material, Patel B. Reddy, Ayman M. El-Refaie, Min Zou, Di Pan, James P. Alexander, Nidhishri Tapadia, Kevin Grace, Kum-Kang Huh, Frank Johnson

Electrical and Computer Engineering Faculty Research and Publications

While interior permanent magnet (1PM) machines have been considered the state-of-the art for traction motors, synchronous reluctance (SynRel) motors with advanced materials can provide a competitive alternative. 1PM machines typically utilize Neodymium 1ron Boron (NdFeB) permanent magnets, which pose an issue in terms of price, sustainability, demagnetization at higher operating temperatures, and uncontrolled generation. On the other hand, SynRel machines do not contain any magnets and are free from these issues. However, the absence of magnets as well the presence of bridges and centerposts limit the flux-weakening capability of a SynRel machine and limit the achievable constant power speed ratio …

Evaluating The Distributional Effects Of Regional Transportation Plans And Projects, Kristine Williams, Aaron Golub

TREC Final Reports

Metropolitan planning organizations (MPOs) have long been required to consider the equity implications of their regional transportation plans and processes. Funded by the National Institute for Transportation and Communities, this research aims to provide additional guidance to MPOs on how to evaluate distributional equity in regional plans and projects. The report begins with an overview of federal requirements related to equity in transportation planning. We then synthesize contemporary methods for measuring transportation equity and the distributional effects of plans and projects from a review of the literature and MPO plans and studies. The report concludes with exploratory case studies of …

Measuring Molecular Orientation And Rotational Mobility Using A Tri-Spot Point Spread Function, Oumeng Zhang

McKelvey School of Engineering Graduate Student Theses & Dissertations

Single molecules have become a powerful tool for biophysicists since they were first optically detected 28 years ago. Understanding molecular orientation can not only improve the accuracy of single-molecule localization, but it can also provide insight into biochemical behaviors at the nanoscale. In this thesis, I present a method to measure the molecular orientation and rotational mobility of single-molecule emitters by designing and implementing a tri-spot point spread function. The point spread function is designed so that it is capable of measuring all degrees of freedom related to molecular orientation and rotational mobility. Its design is optimized by maximizing the …

Conjoint Audiogram Estimation Via Gaussian Process Classification, James Dilorenzo

McKelvey School of Engineering Graduate Student Theses & Dissertations

In traditional audiometry, a clinician seeks to estimate her patient’s auditory response through the sequential delivery of various individual tests. These tests are treated as independent and correlation is assessed after each individual test has been completed, resulting in a diagnosis. Treating tests as independent impedes both accuracy and efficiency by ignoring correlations in conditions known to influence physiological response, for instance age, genetics, and exposure to noise. This thesis advances the existing framework for audiometry via Gaussian Processes by allowing for the estimation of audiogram thresholds for both ears simultaneously. The resulting model estimates both correlated and uncorrelated right- …

Deposition Velocity Dependence On Urban Morphology, Rawand Muzafar Rasheed

Maseeh Summer Undergraduate Research Experience

Understanding the interactions between the atmospheric boundary layer and urban structures provides insights into emerging problems such as green building design as well as dispersion and deposition of pollutants on urban structures. Characterization of deposition velocity dependence through the naphthalene sublimation method on model urban structures is conducted herein where the analogous fundamental transport mechanisms of momentum and mass transport is obtained via mass of naphthalene transferred. Via wind tunnel experiments, results show that deposition velocity of naphthalene from urban structures increases with increased number of urban structures ahead of the point of investigation. This is attributed to the wakes …

The Aerodynamic Effects On Flight Patterns And The Evolutionary Changes In Pterosaurs, Johnathan D. Talik

Maseeh Summer Undergraduate Research Experience

Early pterosaurs were the first vertebrates to achieve powered flight, and remained small-to-medium sized from the Triassic Period to the end of the Jurassic Period. During that interval, lasting from 210 million years ago to 66 million years ago, pterosaurs underwent a notable changes at the end of the Jurassic Period and through the Cretaceous Period. They were abruptly replaced by much larger forms, characterized by great size and peculiar head ornamentation, among other unique and notable morphological features. While many different explanations theorize why and how the features of the pterosaurs changed over the Cretaceous Period, the aerodynamic influences …

Jet Bounce In Low Gravity, Caleb Turner

Maseeh Summer Undergraduate Research Experience

Liquid jets rebound (‘bounce’) from superhydrophobic surfaces when they impinge at oblique angles. We call this interesting phenomena ‘jet bounce’ and in this work we investigate the phenomena at large length scales in a reduced gravitational environment. For example, for water at Reynolds numbers 0 < Re < 3500 and surface normal Weber numbers 0 < We < 60 we characterize the response of the jets on the hydrophobic surface in the brief 2.1s micro-gravity environment achieved using a drop tower. It is observed that by varying jet velocity, flow rate, jet diameter, and incident angle we observe up to four distinct regimes of behavior. The various regimes may be targeted for specific applications and we demonstrate a variety of unique jet bounce behaviors for applications such as no-touch, no-contact fluid-thermal transport for spacecraft unit operations such as contaminated water processing, device cooling, and cryogenic fluids transport and management.

Stable jet bounce from small diameter jet ≈ 1 mm and low impact angle. Characterizing Reynolds number ≈ 900 and normal Weber number ≤ 10 allow jet bounce to rebound in non-destructive behavior.

Flux Focusing Axial Magnetic Gear, Robert J. Rutherford

Maseeh Summer Undergraduate Research Experience

Power transmission is traditionally achieved with a mechanical gear. These gears require maintenance, cause vibration, and have no overload protection. Magnetic gears (MGs) offer an innovative solution to these drawbacks as they do not require regular maintenance, have no need for lubrication, create very little acoustic noise, have built in overload protection and as a result of these advantages, have a longer lifetime of operation. The flux focusing axial magnetic gear (FFAMG) was assembled for future testing of power transmission, conversion, and generation applications.

Gears are used to transmit power by converting low speed-high torque rotary motion into high speed-low …

Design And Test Of 3d Printed Lenses For Sub-Thz Radiation, Justin Patterson

Maseeh Summer Undergraduate Research Experience

The terahertz gap in the electromagnetic spectrum provides promising advantages for applications such as increased airport security and medical diagnosis. Quasi-optical systems used to study THz radiation require multiple mirrors or lenses, which can be quite costly. In order to manipulate THz beams we investigated production of inexpensive lenses using additive 3D printing. 3D printing technology promises to be not only accessible and inexpensive, but should also enable quick experimentation with different lens designs. The Picometrix time-domain spectroscopy (TDS) system was used to characterize 3D printable plastics. The absorption coefficient and refractive index were analyzed from 0.2 to 2 THz …

Conditional Averaging And Classification In The Near Wake Of A Wind Turbine Array Boundary Layer, Sarah E. Smith

Maseeh Summer Undergraduate Research Experience

Flow perturbation induced by interaction with a turbine rotor produces considerable turbulence which can alter the productivity of subsequent units within a wind farm. Previous methods have characterized near wake vorticity of a single turbine as well as recovery distance for various turbine array configurations. This study aims to build from previous methods of analysis from the perspective of the rotor well within a turbine array and develop a model to examine points of significant imposition in relation to rotational effects. Hot wire anemometry was employed downstream of a turbine located in the middle of the third row in a …

The Effect Of Plasma On Graphene Quality In An Inductively Couple Plasma Chemical Vapor Deposition Reactor, Brendan Coyne

Maseeh Summer Undergraduate Research Experience

Despite continued interest in research and application development, full scale graphene production is still limited by many factors including prohibitively high growth temperature requirements. Extremely high quality graphene growth is possible at high temperatures using chemical vapor deposition (CVD). Use of an inductively coupled plasma chemical vapor deposition (ICP CVD) reactor with the benefit of precursor gas decomposition through plasma generation, may provide possibility to reduce growth temperature. Herein, we report plasma’s effects on graphene growth by comparing growths of increasing power supplied to plasma generation and changes in precursor gas ratios. Plasma composition was characterized by ultraviolet and visible …

Computational Modeling Of Electrical And Phonon Properties Of Skutterudites And Two-Dimensional Transition Metal Dichalcogenides, Izaak Gene Williamson

Boise State University Theses and Dissertations

This dissertation documents the computational modeling of skutterudite and two-dimensional transition metal dichalcogenide (2D TMD) materials for energy and electronic applications by analyzing the effects of materials doping and heterostructure formation on structural, energetic, electrical, phonon, and thermal properties. These topics remain largely unexplored and can accelerate materials development by providing insight on structure-properties-performance relationships.

Skutterudites are commonly studied for thermoelectric applications because they are low-cost, easy to process, and offer good intrinsic transport properties. They also exist as large, open structures which can be altered through filler atoms or substitutional dopants. A density functional theory (DFT)-based investigation of dopant …

Evaluation Of Flux Correction On Three-Dimensional Strand Grids With An Overset Cartesian Grid, Dalon G. Work

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Simulations of fluid flows over complex geometries are typically solved using a solution technique known as the overset meshing method. The geometry is meshed using grid types appropriate to the local geometry in a patchwork fashion, rather than meshing the entire geometry with one type of mesh. The strand-Cartesian approach is a simplification of this process. While high-order accurate solvers on Cartesian grids are simple to implement, strand grids are usually restricted to second-order accuracy, resulting in poor quality solutions. Flux correction is a high-order accurate solution method, specifically designed for use on strand grids. The flux correction method on …

Characterization Of The Thermal Resistance Of Grain Boundaries Of Cerium Oxide, Jesse Spackman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many materials are made up of small crystals, or grains. Grain boundaries are the interfaces between two grains and affect the flow of heat through the material. These interfaces serve to interfere with the energy carriers by scattering or disrupting them. Because of the negative effect these interfaces have on these energy carriers, they inhibit heat flow and act as thermal resistors. The thermal boundary resistance between two grains of the same material is sometimes referred to as the Kapitza resistance, although this term is also used to describe the thermal resistance between solid/solid interfaces of different materials or solid/liquid …

Water Entry Impact Dynamics Of Diving Birds, Saberul Islam Sharker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plunge diving and surface diving are two main techniques used by seabirds for foraging purposes. While some plunge divers can dive into the water at very high speeds (24 m/s), surface divers do not. This study analyzes the free-surface impact of 3D printed bird head models with embedded accelerometers to determine why surface divers cannot dive safely at high speeds. The problem is investigated in the context of impact jerk where surface divers, unlike plunge divers, are found to experience non-dimensional jerk (J^∗) values exceeding a safe limit. This approach portrays itself as an unconventional yet effective method …

Mechanical Performance Of Natural / Natural Fiber Reinforced Hybrid Composite Materials Using Finite Element Method Based Micromechanics And Experiments, Muhammad Ziaur Rahman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A micromechanical analysis of the representative volume element (RVE) of a unidirectional flax/jute fiber reinforced epoxy composite is performed using finite element analysis (FEA). To do so, first effective mechanical properties of flax fiber and jute fiber are evaluated numerically and then used in evaluating the effective properties of flax/jute/epoxy hybrid composite. Mechanics of Structure Genome (MSG), a new homogenization tool developed in Purdue University, is used to calculate the homogenized effective properties. Numerical results are compared with analytical solution based on rule of mixture, Halpin-Tsai as well as Tsai-Hahn equations. The effect of the volume fraction of the two …

Spatial And Temporal Study Of Heat Transport Of Hydrothermal Features In Norris Geyser Basin, Yellowstone National Park, Ruba A. M. Mohamed

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Monitoring thermal activity in Yellowstone National Park is required by the United States Congress to maintain the safety of the visitors and park service personnel and to protect the integrity of the park. This dissertation is part of a study initiated in the early 2000s to monitor the thermal activity in the park with focus on Norris Geyser Basin, the hottest geyser basin in the park. The study is considered the first multiple-year study in the basin which took place between August 2008 and October 2013. In this study, at least one thermal infrared image was acquired every year using …

Vision-Based Control Of A Full-Size Car By Lane Detection, N. Chase Kunz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Self-driving cars are an area of increasing investment for researchers and auto manufacturers. Integration has already begun for such vehicles in urban environments. An essential aspect of navigation in these areas is the ability to sense and follow lane markers. This thesis focuses on the development of a self-driving, full-size, electric car which uses only a camera and lane markers to stay on the road. A complete method for automation is shown for a stock vehicle. Discussion includes reverse engineering of the steering, braking, and acceleration signals, as well as methods for lane detection and full-vehicle control.

Nonlinear Photothermal Radiometry And Its Applications To Pyrometry And Thermal Property Measurements, Austin Drew Fleming

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Accurate temperature and thermal property measurements are critical for the modeling and prediction of heat transfer. In many industries thermal management is a limiting factor of performance, and rely on advanced modeling techniques to develop and design methods to better manage thermal energy. This study expands the thermal property and pyrometry measurement capabilities by developing three new techniques based on thermal emission’s nonlinear dependence on temperature.

Developing A General Methodology For Evaluating Composite Action In Insulated Wall Panels, Jaiden Thomas Olsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Precast Concrete Sandwich Panel Walls (PCSPW’s) have been in use for over 60 years. They provide a very efficient building envelope for many buildings. Characteristic PCSPW’s comprise an outer and inner layer (or wythe) of concrete separated by an insulating material. To use all of the material as efficiently as possible, the layers are attached by connectors which penetrate through the insulating layer and are embedded in either concrete wythe. These connectors make it possible for both layers of the wall to work together when resisting loads. The connectors are made out of plastic, or FRP, to prevent heat transfer …

Computer-Aided Design Integration In Virtual Reality Design Reviews For Improved Interaction With Engineering Models, Ian James Freeman

Theses and Dissertations

Leveraging virtual reality (VR) technology to enhance engineering design reviews has been an area of significant interest for researchers since the advent of modern VR. The ability to interact meaningfully with 3D engineering models in these VR design reviews is an important, though often neglected, capability due to the difficulty of performing data translation between native CAD data and VR compatible file formats. A bi-directional interface was developed between a VR design review environment and a commercial CAD package that streamlines the data translation process. By transmitting both geometric data and selected metadata from the CAD system an improved format …

Em Wave Interaction With A Bounded Plasma Column Supporting An Electron Beam, Asmelash Teshome Beshah

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this thesis, the disruption of an incoming external transverse electromagnetic wave by an inhomogeneous plasma with energetic electron beam is examined. The plasma-beam characteristics are motivated by theory and experiment. Wave-plasma interactions and wave propagation and reflection in and from a plasma medium is studied. Physical sources such as the plate current density are considered. The inhomogeneity of the plasma slab supporting the energetic electron beam is partially built into the supported fields. The wave-plasma-beam interaction is examined over a wide parameter space. Absorption or reflection of electromagnetic waves can be achieved by changing the plasma number density, collision …

High Early-Age Strength Concrete For Rapid Repair, Matthew O. Maler

UNLV Theses, Dissertations, Professional Papers, and Capstones

The aim of this research was to identify High Early-Age Strength (HES) concrete batch designs, and evaluate their suitability for use in the rapid repair of highways and bridge decks. To this end, two criteria needed to be met; a minimum compressive strength of 20.68 MPa (3000 psi) in no later than 12 hours, and a drying shrinkage of less than 0.06 % at 28 days after curing. The evaluations included both air-entrained, and non-air-entrained concretes.

The cement types chosen for this study included Type III and Type V Portland cement and “Rapid Set” − a Calcium Sulfoaluminate (CSA) cement. …

Design, Fabrication And Testing Of A Capacitive Sensor Using Delta-Sigma Modulation, Charikleia Tsagkari

UNLV Theses, Dissertations, Professional Papers, and Capstones

Capacitive sensing is a popular technology employed in billions of products and millions of applications. This Thesis details the design, layout and characterization of an Integrated Circuit (IC) that employs Delta-Sigma Modulation (DSM) for sensing capacitance. The chip, measuring 1.5 mm x 1.5 mm, was designed in On Semiconductor’s C5 process and was manufactured by MOSIS.

The sensing circuit links linearly the ratio of a “test” to a “reference” capacitance to the output of a Delta-Sigma Modulator. The equations that describe the operation of the sensing circuit are derived. Besides the sensing circuit, there is a non-overlapping clock generator that …

Statistical Models Of I-15 Bridge C-846: Changes In Natural Frequencies Due To Temperature, Gilbert Nichols

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Structural Health monitoring is to determine the condition of a bridge based on instrument measurements. The C-846 Bridge in Salt Lake City has such instrumentation. The bridge is located in Salt Lake City at about 2100 South and Interstate 15. This bridge has two kinds of instruments on it: accelerometers and thermocouples. The accelerometers measure the vibrations of the bridge. The accelerometers have been recording data on the bridge since 2001. The thermocouples, which measure temperature, were added as part of this thesis in April 2016.

In light of recent research, damage may be detected from measuring the change in …

Optimization Of Roadway Electrification Integrating Wireless Power Transfer: Technoeconomic Assessment And Lifecycle Analysis, Braden J. Limb

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Electric vehicles are the main technology currently being pursued to reduce dependence on fossil fuels in the transportation sector. These vehicles provide both reduced greenhouse gas emissions and decreased operating costs when compared to conventional internal combustion vehicles, while providing the flexibility to use both renewable and fossil energy. However, these vehicles have seen limited consumer adoption due to their large purchase prices and limited driving range. Both purchase price and driving range are related to the large onboard battery systems required for electric vehicle travel.

One solution to decrease dependence on large battery systems has focused on charging vehicles …

Integrated Life Cycle And Techno-Economic Assessment Of The Conversion Of High Productivity, Low Lipid Algae To Renewable Fuels, Chad R. De Mill

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The production of alternative transportation fuels is imperative to meet future energy demands without contributing to global climate change. Advances in alternative processing techniques that have emerged due to interest in microalgae as a feedstock have led to a variety of potential processing pathways for the production of bio-based fuels. A major hurdle in the algal production process is maintaining a fast and stable algae culture. Monocultures, developed for their high lipid content, suffer from low productivity, are susceptible to crashes and require a constant supply of carbon dioxide to maintain productivity. In an effort to circumvent these obstacles, algal …

Uncertainty Of Stereo Piv Calibration And Self-Calibration, Braydon J. Williams

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Particle image velocimetry (PIV) is a widely used fluid measurement technique. Three dimensional PIV data or stereo PIV is acquired using two cameras. Stereo cameras are calibrated from camera coordinates, pixels, to real world units such as millimeters using calibration models. Stereo calibration is fundamental to the accuracy of a PIV measurement. In this thesis, the accuracy of the stereo calibration is assessed. The mean error of stereo calibration was found to be 0.23%.

Comparing The Effect Of Carbon Sources, Lactate And Whey, On Biological Reductive Dechlorination Of Tce In Laboratory Flow Through Columns, Sarah M. Kissell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Trichloroethylene (TCE) is a chlorinated solvent most commonly used as an industrial degreaser for cleaning mechanical equipment. Historic improper management and disposal of TCE has resulted in contaminated soil and groundwater across the United States, including Hill Air Force Base in Utah. The abundance of TCE in the environment presents a public health risk because it is categorized as a Group 1 carcinogen by the International Agency for Research on Cancer (IARC).

The purpose of this study was to improve the bioremediation techniques of biostimulation and bioaugmentation. A continuous flow-through column study was performed where columns packed with aquifer material …

Prestress Losses And Temperature Effects On A Deck Bulb Tee Girder Bridge, Phillip Powelson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Utah Transportation Center (UTC), in partnership with the Mountain Plains Consortium (MPC), sponsored a study to investigate the differences in prestress losses and temperature gradients in a concrete deck bulb tee girder bridge. The Millville Bridge was built as an access point to the Ridgeline High School in Millville, Utah. The bridge was built in 2016 and presently supports two lanes of traffic.

Changes in prestress were measured with a total of 16 vibrating wire strain gauges located at four cross-sections. Temperature gradients were measured with a total of 50 thermocouples located at five cross-section locations, four of which …