Engineering Commons^™

Plasma Aerodynamics: Experimental Quantification Of The Lift Force Generated On An Airfoil Using Plasma Actuation To Estimate Power Requirements In Small Uav Applications, Getachew Ashenafi

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research addressed the amount of electric power required to induce specific changes in lift force using a NACA 2127 airfoil with a chord length of ~28 mm, connected to a micro load cell, in a wind tunnel of 103 square centimeter cross-section. A DBD plasma actuator supplied by a ZVS driven high voltage pulsed DC circuit, operating at a frequency of 17.4 kHz, was utilized for voltages of up to 5000 V. Two configurations of electrode gapping were compared to determine the efficient use of power. The configuration with a gap of ~1 mm between the upstream and downstream …

Dynamic Analysis Of A Microgrid Powered With An Inverter And Machine-Based Distributed Resources, Brandon William Blackstone

UNLV Theses, Dissertations, Professional Papers, and Capstones

The proliferation of renewable distributed energy resources, particularly photovoltaic (PV) power systems, and the increasing need for a reliable power supply has led to the concept of microgrids, a mini-grid that consists of locally connected power generation units and needs, able to operate connected or disconnected from the utility grid, using controlled and coordinated methods to provide for the users of the microgrid the best possible conditions for their needs. The main technical issues facing microgrids include some of the following, seamless transition from stand-alone to utility grid connected operation, how to preserve frequency and voltage stability, and provide the …

Developing Lrfd Side Shear And End Bearing Resistance Factors For Design Of Axially Loaded Drilled Shafts In Soil Containing Caliche Layers Using The Monte Carlo Approach, Visar Farhangi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Conventional design and construction procedures of the drilled shafts (bored piles) are mainly developed for homogenous soils in the absence of highly cemented layers. However, the presence of competent and cementitious layers such as caliche deposits in soil profile can affect the resistance and settlement of pile foundations. This study concerns with the uncertainties on the resistance estimation of axially loaded drilled shafts in interaction with caliche layers The prime objective is to calibrate the side shear and end bearing resistance factors of axially loaded drilled shafts based on the soil characteristics of Nevada. The load-settlement responses of axially loaded …

Behavior Of Aged Reinforced Concrete Columns Under High Sustained Concentric And Eccentric Loads, Wenchen Ma

UNLV Theses, Dissertations, Professional Papers, and Capstones

Columns are critical components resisting the collapse of a reinforced concrete (RC) frame structure subjected to high sustained loads. Research on columns under sustained high stresses is very limited. At material level, past creep tests were focused either on concrete with ages less than 90 days or under a sustained stress less than 70% of short-time strength. At structural component scale, virtually no experimental data can be found for the response of axially loaded RC columns subjected to high sustained loads exceeding 75% of column short-time strength with loading age greater than 200 days. Even if a few experiments were …

A Hyperelastic Porous Media Framework For Ionic Polymer-Metal Composites And Characterization Of Transduction Phenomena Via Dimensional Analysis And Nonlinear Regression, Zakai J. Olsen

UNLV Theses, Dissertations, Professional Papers, and Capstones

Ionic polymer-metal composites (IPMC) are smart materials that exhibit large deformation in response to small applied voltages, and conversely generate detectable electrical signals in response to mechanical deformations. The study of IPMC materials is a rich field of research, and an interesting intersection of material science, electrochemistry, continuum mechanics, and thermodynamics. Due to their electromechanical and mechanoelectrical transduction capabilities, IPMCs find many applications in robotics, soft robotics, artificial muscles, and biomimetics. This study aims to investigate the dominating physical phenomena that underly the actuation and sensing behavior of IPMC materials. This analysis is made possible by developing a new, hyperelastic …

Investigation Of Bench-Scale Packed Bioreactor For Perchlorate Reduction In The Presence Of Co-Contaminants And High Salinity, Julia Ribeiro Rabello

UNLV Theses, Dissertations, Professional Papers, and Capstones

Perchlorate (ClO4-), commonly found as a salt, is naturally occurring in nature and is found in natural nitrate deposits (such as the Chilean nitrate). Perchlorate anion is considered an inhibitor of iodine by the thyroid gland, reducing the production of thyroid hormones. The latest action by the USEPA was to not determine a national drinking water standard for perchlorate. However, the states still have their own regulations on perchlorate concentration in drinking water. Contaminated sites with high concentrations of perchlorate (ppm levels) are associated with historic perchlorate manufacture and use, while those with low concentrations (ppb levels) are found in …

Patient-Specific Finite Element Analysis For Mandibular Fracture Fixation, Ethan Snyder

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis proposes an approach for Finite Element Analysis (FEA) of mandibular fracture fixation. Using a Computerized Tomography (CT) scan of mandible obtained from a specific person, the material characteristics, density and modulus of elasticity, were determined from a set of discrete points within the mandible that are 1mm spaced based on the Hounsfield Units of these points. The mandible geometry was sectioned to simulate a fracture. Muscle and mastication forces were added to replicate post-surgery loading. Using a standard linear miniplate, this material model was compared with two commonly used mandibular cortical shell bone models: isotropic and orthotropic. A …

Degradation Of Antibiotics In Aqueous Phase Using Pms Catalytic Decomposition With Zero-Valent Iron Nanoparticles Immobilized In Sba-15, Ahdee Bluma Zeidman

UNLV Theses, Dissertations, Professional Papers, and Capstones

Zero-valent iron nanoparticles (nZVI) have been studied as an option for soil remediation and water treatment for many years. The capability of nZVI to produce oxidation/reduction processes, depending on the reaction conditions, has attracted great interest with their major drawback being reactivity loss through agglomeration. The loss in nZVI surface area has been reported to be prevented through immobilization onto a porous media (e.g., SBA-15, MCM-41, or zeolites). In this work, a mesoporous silica structure (SBA-15) is used as an nZVI supporting material to enhance its reactivity and promote peroxymonosulfate (PMS) catalytic decomposition for the degradation of antibiotics in aqueous …

On The Computational Efficiency Of Les And Hybrid Rans-Les Models In Building Aerodynamics, Faiaz Khaled, Aly Mousaad Aly

Faculty Publications

No abstract provided.

Optimizing Garbage Pick-Up In Wahoo, Ne, Andrew Pace

Theses/Capstones/Creative Projects

This project seeks to optimize the garbage pickup routes of Roadrunner Transportation in Wahoo, Nebraska using operations research and optimization tools. Currently, the company has no formal procedure for determining these routes. Roadrunner Transportation would like to expand their operation and to do so in the most efficient manner. To determine efficient routes, the Capacitated Vehicle Routing Problem (CVRP) is applied, and a solution to this problem is obtained by implementing a simulated annealing heuristic algorithm. Results show that a total distance of approximately 70 miles can be obtained by this implementation using a small subset of the data provided …

Synthesizer Parameter Approximation By Deep Learning, Daniel Faronbi, Alisa Gilmore

Theses/Capstones/Creative Projects

Synthesizers have been an essential tool for composers of any style of music including computer generated sound. They allow for an expansion in timbral variety to the orchestration of a piece of music or sound scape. Sound designers are trained to be able to recreate a timbre in their head using a synthesizer. This works well for simple sounds but becomes more difficult as the number of parameters required to produce a specific timbre increase. The goal of this research project is to formulate a method for synthesizers to approximate a timbre given an input audio sample using deep learning. …

Analysis Of Air Taxi Accidents (20042018) And Associated Human Factors By Aircraft Performance Class, Don Budde, Jochen Hinkelbein, Douglas D. Boyd

Publications

INTRODUCTION: Air taxis conduct nonscheduled transport and employ aircraft in various performance categories hereafter referred to as low, medium, and high performance, respectively. No study has yet addressed fixed-wing air taxi safety by performance category. Herein, we compared accident rates/occupant injury across air taxi airplane fleets grouped by performance category and identified human factors contributing to fatal accidents for airplanes in that category with the highest mishap rate. METHODS: Accidents (20042018) in the United States were identified from the National Transportation Safety Board database. General Aviation/Part 135 Activity Surveys provided annual fleet times. Fatal accident contributing factors were per the …

Autonomous Aerial Vehicle Vision And Sensor Guided Landing, Gabriel Bitencourt, Elijah J. Brown, Cedric Bleimling, Gilbert Lai, Arman Molki, Tolga Kaya

School of Computer Science & Engineering Faculty Publications

The use of autonomous landing of aerial vehicles is increasing in demand. Applications of this ability can range from simple drone delivery to unmanned military missions. To be able to land at a spot identified by local information, such as a visual marker, creates an efficient and versatile solution. This allows for a more user/consumer friendly device overall. To achieve this goal the use of computer vision and an array of ranging sensors will be explored. In our approach we utilized an April Tag as our location identifier and point of reference. MATLAB/Simulink interface was used to develop the platform …

Fluid Powered Vehicle Challenge: Team Soulenoid Cycle, Kellen Muir Giuliani, Jordan David Kochavi, Cayla Renee Quinn, Martin Reyes

Mechanical Engineering

The National Fluid Power Association is a trade association that unifies customers and manufacturers within the hydraulics industry. Extending their partnership to universities, the annual Fluid Powered Vehicle Competition challenges college teams to design, build, and test a fluid-powered vehicle with the goal of educating students about the hydraulics industry and building career connections. Soulenoid Cycle produced the next iteration of Cal Poly’s fluid powered vehicle for the 2021 competition.

This report summarizes research, ideation, component selection, initial and final design, manufacturing, and competition results conducted by Soulenoid Cycle. Relevant research includes successful current and past vehicles, the operation of …

Improving Operational Hydrologic Forecasting Via Conditional Bias-Penalized Multi-Sensor Precipitation Estimation And Multi-Model Streamflow Prediction, Ali Jozaghi

Civil Engineering Dissertations - Archive

Many multivariate analysis techniques involve minimizing mean square error (MSE) or error variance under unbiasedness. In the presence of observation error, variance minimization tends to introduce negative and positive biases, or conditional bias (CB), over the upper and lower tails of the predictands, respectively. This work describes and evaluates three multivariate merging techniques, 1) adaptive conditional bias-penalized cokriging (CBPCK), 2) conditional bias-penalized Multiple Linear Regression (CBP-MLR), and 3) conditional bias-penalized Bayesian Model Averaging (CBP-BMA) which implements CBP-MLR in place of MLR. CBPCK and CBP-MLR minimize a linearly weighted sum of errors squared and the sum of the Type-II error squared, …

A Moving Target Defense For Securing Cyber-Physical Systems, Paul Griffioen, Sean Weerakkody, Bruno Sinopoli

Faculty Work Comprehensive List

This article considers the design and analysis of multiple moving target defenses for recognizing and isolating attacks on cyber-physical systems. We consider attackers who perform integrity attacks on some set of sensors and actuators in a control system. In such cases, it has been shown that a model aware adversary can carefully design attack vectors to bypass bad data detection and identification filters while causing damage to the control system. To counter such an attacker, we propose the moving target defense which introduces stochastic, time-varying parameters in the control system. The underlying random dynamics of the system limit an attacker’s …

Light Intensity Control For Plc-Based Hydroponic Demonstration System, Christian Hitt

Biological and Agricultural Engineering Undergraduate Honors Theses

In order to demonstrate a skill set obtained through the University of Arkansas Biological Engineering, a group of students and I developed a hydroponic system where plants could be grown in a chamber. System parameters such as air quality, irrigation, and lighting were controlled by a Programmable Logic Computer (PLC) and an array of sensors and actuators. Each student focused on a certain aspect of this system, mine being the lighting. Developing this system involved researching the relationship between light intensity and plant growth, designing a system to suspend the lights above the growth chamber, and develop a system to …

Teenage Cyclists’ Perception Towards Autonomous Vehicles And Its Associated Traffic Infrastructures, Obiageli Lawrentia Ngwu

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

Background: Cycling is a cost-effective means of transportation. Many teenagers cycle to go to schools and ride in neighborhoods. Cyclists are more vulnerable to injuries and fatalities than motor vehicle drivers. With the implementation of autonomous vehicles (AVs), interactions between AVs and road-users are expected to be safer. It is most likely that current young people will be the ones to use these vehicles and interact with them. However, very few past studies have focused on cyclist-AV interaction, with little to no attention toward the teenage cyclist population. Objectives: This study is aimed at examining teenage cyclists’ perceptions of AVs …

Mathematical Modeling Of A Two Wheeled Robotic Base, Kathryn Remell

Mechanical Engineering Undergraduate Honors Theses

This thesis presents the concept of using a two wheeled robot on the moon and briefly explores the requirements for successful long term operation in a lunar environment. The mathematical model for the motion of a robot with two fixed wheels on a differential drive with in a global reference frame. The robot is assumed to be balancing a platform so the mathematical model to balance the platform with wheel motors is also developed and briefly evaluated.

Characterizing High Entropy Alloys For Hypersonic Applications, Katherine Pettus

Mechanical Engineering Undergraduate Honors Theses

In this paper, the properties of a new and broad class of materials, high entropy alloys (HEAs), were investigated and evaluated for hypersonic applications. The plan was to identify candidate hypersonic HEAs and model the high-temperature strength using new advanced material models that account for asymmetry and anisotropy characterized with available test data. After accessing a local database of HEAs and their material properties in collaboration with Dr. Gorsse et al., it was realized the knowledge of HEAs is currently very broad but lacks depth. While hundreds of HEAs have been created and tested, none so far have both sufficient …

Improving The Performance Of An Ead Aircraft By Use Of A Retractable Electrode System, Michael Alexander Fredricks

Mechanical Engineering Undergraduate Honors Theses

Electroaerodynamic (EAD) propulsion is a growing area of research for small, low powered aircraft. Recent tests of EAD aircraft have demonstrated low performance in unpowered, gliding flight. The purpose of this paper is to investigate the effect of a retractable electrode system on the flight performance of an EAD aircraft. An analysis of electrode drag contribution on the MIT ionic wind plane’s performance predicts a maximum lift to drag ratio of 22, with the addition of a retractable electrode system, for a similarly sized and modeled EAD aircraft. An experiment is developed using a prototype aircraft, launcher, and retraction system …

Feasibility Study: Alternatives To Prevent Settlements And Bumps At Bridge Approach, Seunghee Kim, Jongwan Eun, Yusuf Alhowaidi, Daniel Robertson

Nebraska Department of Transportation: Research Reports

This project aims to examine the feasibility of improving the current design practice of the approach slab foundation in Nebraska and the alternative of using geosynthetic reinforcement of soils to prevent the bump issues near the end of bridge approaches via an in-depth numerical simulation study. A large-scale pullout test is also conducted as complementary to provide input parameters for the interaction between the regional soil and selected geosynthetics. Based on the results, it is recommended that the number of grade beam piles could be reduced to 40-50 % of the total number of abutment piles while maintaining the same …

Evaluating Asct Operations For Dodge Street Corridor, Anuj Sharma, Subhadipto Poddar, Atousa Zarindast, Christopher Day

Nebraska Department of Transportation: Research Reports

As Adaptive Traffic Control (ATC) is increasingly being implemented by various traffic agencies, careful evaluation is needed of the degree to which a given ATC implementation improves traffic signal performance. The present study details the evaluation of ATC for two arterial corridors in the City of Omaha, Nebraska. Several performance measures were used across two stages of ATC implementation as well as during the unanticipated COVID-19 lockdown stage.

The average travel time and variability in travel time showed that Stage 1 of ATC implementation in Omaha did not improve traffic signal performance for the study’s main corridor, Dodge Street. This …

Aiming For The Sun- Averting The Fate Of Icarus: De-Risking Solar Energy Projects, Manu Srivastava

Asian Management Insights

Climate change is increasingly accepted as an existential threat to civilisation and ‘business as usual’ is considered a luxury we cannot afford any more.

Development Of A Computational Framework For Estimating Knee Joint Contact Forces In Running, Sean W. Kapp

Honors Theses

The prevalence of running as a form of exercise and the necessity of walking for simple locomotion obscure massive forces and moments within the body. An especial area of concern is the knee, as common among these injuries is knee pain as a result from high impact on the ground or ground reaction forces. These forces are altered by the foot strike pattern of the individual; in this study, either rearfoot strike (RFS) or forefoot strike (FFS). This alteration will impact internal forces conducted upward through the body. Given the complexity of the motion of running and the forces involved, …

Photobiomodulation Of Neural Stem Cell Differentiation Using Infrared (810 Nm) Laser Stimulation, Noemi Salgado Cordova

Bioengineering Theses - Archive

The standardized clinical use of photobiomodulation (PBM) across many applications has been obstructed due to the lack of understanding in how each of the parameters affect the end results. Although the optimal parameters for the therapy have been estimated with a level of uncertainty, the positive effects have been documented on cell differentiation, wound healing, brain modulation, etc. These positive effects observed by PBM have been attributed to the increase in reactive oxygen species (ROS), nitric oxide (NO), and ATP along other molecules generated by the stimulation of Cytochrome-C Oxidase (CCO). Although there is much uncertainty surrounding the coupling mechanisms …

Exploring Imaging Technology In The Diagnosis And Treatment Of Pediatric Medically Refractory Epilepsy With Intracranial Electroencephalography And Post-Surgical Evaluations, Nasheha Baset

Bioengineering Theses - Archive

Abstract Exploring Imaging Technology in the Diagnosis and Treatment of Pediatric Medically Refractory Epilepsy with Intracranial Electroencephalography and Post-Surgical Evaluations Nasheha Baset, MS The University of Texas at Arlington, May 2021 Supervising Professor: Dr. Christos Papadelis Epilepsy is a disorder that commonly causes seizures due to abnormal neurological activity, which can disrupt daily life. Of all patients with epilepsy, 60% suffer from focal epilepsy. Approximately 15% of these cases are considered to be drug resistant, or refractory, as the patient is not responsive to a combination of two or more anti-epileptic drugs (AED). Traditionally, approaches to treatment of medically refractory …

Utilizing The Oxygen-Barrier Properties Of Poly(Isobutylene) To Enhance Photon Upconversion In Thermoplastic Elastomers, Haley Carroll

Honors Theses

Upconversion (UC) is the conversion of low energy light to higher energy light. It is utilized for a broad range of applications such as solar energy harvesting, microscopy of cellular biology, and cancer therapy. Specifically, triplet-triplet annihilation UC (TTA-UC) involves two dye species, a sensitizer and an annihilator, which are capable of upconverting noncoherent light such as sunlight. Traditionally, TTA-UC is achieved in solution, rubbers, or glasses, however, this work probes the capabilities of a thermoplastic elastomer (TPE) matrix to examine the effect of phase-separated morphology on the energy transfers necessary for TTA-UC. The system herein consists of poly(styrene-isobutylene-styrene) (SIBstar) …

Effects Of Static Mixer Geometry On Polyurethane Properties, Christian R. Dixon

Honors Theses

The field of additive manufacturing has gained significant academic interest in the past few decades with a recently developed type of three-dimensional (3D) printing. Reactive extrusion additive manufacturing combines precursor materials within a static mixer (SM) head, where polymerization begins before deposition. Variable static mixer geometries currently exist, but the relationship between mixer geometry and post-polymerization mechanical properties is undefined. To elucidate this relationship, a series of experiments with identical chemistry was performed using a high shear SM, a low shear SM, and a comparative batch reaction. While higher shear mixing trends with faster polymerization for step-growth polymerizations, consistent precursor …

Real-Time Motion Tracking Of Cognitive Baxter Robot Based On Differential Inverse Kinematics, Shaobo Li, Xingxing Zhang, Jing Yang, Qiang Bai, Jianjun Hu, Qisong Song, Zhiang Li

Faculty Publications

The tracking motion of the robot is realized based on a specific robot or relying on an expensive movement acquisition system. It has the problems of complex control procedures, lack of real-time performance, and difficulty in achieving secondary development. We propose a robot real-time tracking control method based on the control principle of differential inverse kinematics, which fuses the position and joint angle information of the robot’s actuators to realize the real-time estimation of the user’s movement during the tracking process. The motion coordinates of each joint of the robot are calculated and the coordinate conversion between man and machine …