Engineering Commons^™

Discrete Element Modeling Of The Shape- And History-Dependent Behavior Of Granular Materials, Feiyang Chen

All Dissertations

Granular materials, such as biomass feedstocks, agricultural grains, pharmaceutical pills, and geomaterials, are widespread in nature, industrial systems, and everyday life. Fundamentally, the bulk mechanical behavior of granular materials is governed by particle-level attributes such as particle morphology, surface roughness, and contact behavior. Among various numerical methods developed for modeling granular materials, the particle-based discrete element method (DEM) is particularly suited and effective in modeling the mechanical, flow, and failure behavior of granular materials.

Focusing on one specific type of granular material (i.e., biomass feedstocks), the main objective of this dissertation is to develop and validate novel DEM models that …

Nonviral Approaches For Delivery Of Crispr-Cas9 Into Hepatocytes For Treatment Of Inherited Metabolic Disease, Tanner R. Rathbone

All Dissertations

Inherited metabolic diseases (IMDs) of the liver have a collective occurrence of about 1 in 800 births. Current therapies for IMDs of the liver are limited, and the only curative option for patients is orthotopic liver transplantation. Due to shortages of organ donors, immunosuppression following the transplantation, and mortality risks associated with the procedure, alternative treatment options are necessary for curing IMDs of the liver. Therapeutic gene editing has been proposed as a potential strategy for treating IMDs of the liver. Adeno-associated viral vectors (AAVs) are the most widely used delivery method for liver-targeted gene therapies. Although widely used for …

Using Safety Performance Models, Autonomous Vehicle Data, And Machine Learning To Develop Contextual Complexity Criteria To Establish A Standardized Process For On-Road Evaluation Of Medically At-Risk Drivers Considering Static And Dynamic Factors Of The Roadway Environment, Vijay Bendigeri

All Dissertations

The field of transportation engineering has an opportunity to positively impact the medical community, specifically the clinicians who evaluate, train, and rehabilitate at-risk drivers. Driving Rehabilitation Specialists (DRSs) have an essential role in making roads safer for medically-at-risk drivers, their passengers, and other road users. DRSs conduct on-road driving evaluations, which are considered the gold standard to make fitness-to-drive decisions due to their high face validity. Most DRSs use a fixed route, meaning the exact same route is used to evaluate each client. When a DRS develops a fixed route, that clinician identifies characteristics of the roadway they think are …

A Study Of Scheduling Problems With Sequence Dependent Restrictions And Preferences, Nitin Srinath

All Dissertations

In some applications like fabric dying, semiconductor wafer processing, and flexible manufacturing, the machines being used to process jobs must be set up and serviced frequently. These setup processes and associated setup times between jobs often depend on the jobs and the sequence in which jobs are placed onto machines. That is, the scheduling of jobs on machines must account for the sequence-dependent setup times as well. These setup times can be a major factor in operational costs. In fabric dyeing processes, the sequence in which jobs are processed is also important for quality, i.e., there is a strong preference …

Double Tolerance Design In Stochastic Production Environments, Di Liu

All Dissertations

In a production process, it is impossible to produce parts with exact specifications. Thus, specific ranges, i.e., tolerances, are commonly employed to define intervals for the quality characteristics of conforming products (Wu & Tang (1998)). Usually, a product is deemed conforming when the measurement of the quality characteristic falls within the tolerance. If the measurement falls outside the tolerance, the product is nonconforming and it can be reworked or scrapped. One of the important engineering problems commonly faced by practitioners is to determine optimal engineering tolerances to be used in production. As a result, tolerance design techniques are widely used …

Characterization Of Friction Element Welding Using Finite Element Modeling, Ankit Varma

All Dissertations

Friction element welding (FEW) has been advocated as a solution to weld different materials together, with the ability to join high-strength materials for a range of thicknesses with low input energy and a short processing time. This work develops a coupled thermal-mechanical finite element model to better understand the physical mechanisms involved in the process and to predict temperature and material flow during the process. Furthermore, microstructural analysis is performed for the steel layer using a scanning electron microscope and Vickers microhardness tester to understand the variation in its grain structure and hardness. Results from the finite element model and …

Extractive Membranes For The Detection And Screening Of Waterborne Plutonium, James Foster

All Dissertations

The development of rapid screening tools for special nuclear materials remains a crucial focus for nonproliferation efforts. Traditional approaches for the analysis of trace-level Pu isotopes in water requires tedious and time-consuming sample preparation steps that do not lend well to expeditious screening. Therefore, a novel analytical method that combines both Pu concentration and source preparation into a single detection system would make for an invaluable tool for nuclear security applications. Extractive membranes absorbers can help to fulfill this role as they are capable of concentrating Pu to detectable limits while subsequently serving as alpha spectrometry sample sources. In Chapter …

Control, Decision-Making, And Learning Approaches For Connected And Autonomous Driving Systems With Humans-In-The-Loop, Fangjian Li

All Dissertations

By virtue of vehicular connectivity and automation, the vehicle becomes increasingly intelligent and self-driving capable. However, no matter what automation level the vehicle can achieve, humans will still be in the loop despite their roles. First, considering the manual driving car as a disturbance to the connected and autonomous vehicles (CAVs), a novel string stability is proposed for mixed traffic platoons consisting of both autonomous and manual driving cars to guarantee acceptable motion fluctuation and platoon safety. Furthermore, humans are naturally considered as the rider in the passenger vehicle. A human-centered cooperative adaptive cruise control (CACC) is designed to improve …

Development And Application Of 3d Kinematic Methodologies For Biomechanical Modelling In Adaptive Sports And Rehabilitation, Anne Marie Severyn

All Dissertations

Biomechanical analysis is widely used to assess human movement sciences, specifically using three-dimensional motion capture modelling. There are unprecedented opportunities to increase quantitative knowledge of rehabilitation and recreation for disadvantaged population groups. Specifically, 3D models and movement profiles for human gait analysis were generated with emphasis on post-stroke patients, with direct model translation to analyze equivalent measurements while horseback riding in use of the alternative form of rehabilitation, equine assisted activities and therapies (EAAT) or hippotherapy (HPOT). Significant improvements in gait symmetry and velocity were found within an inpatient rehabilitation setting for patients following a stroke, and the developed movement …

Sustainable Composites From Agricultural And Petroleum Waste, Menisha S. Karunarathna

All Dissertations

Green gas emission has been a pervasive and persistent subject of debate for a prolonged period. The soaring number of industries and vehicle fuel emissions presage a concomitant rise in global CO₂ emissions. Global cement production is responsible for 8% of the total CO₂ release, yet, the production continues due to the surging demand. Hence, there is an ongoing quest to find alternatives for cement and building materials produced with zero to lower CO₂ emissions. The work presented in this dissertation focuses on finding recyclable, zero CO₂ gas-producing high sulfur biocomposites materials, which can compete with …

Single Asperity Fretting Corrosion Of Traditional And Additively Manufactured Metallic Biomaterials: Quantitative Analysis From Acetabular Tapers To Micron And Nanometer Scale Tribocorrosion, Annsley Mace

All Dissertations

Mechanically assisted crevice corrosion (MACC) of metallic biomaterials continues to be a significant degradation mode. This is, in part, due to a lack of understanding of fundamental micron- and sub-micron scale mechanisms of metal degradation in biological environments. Metal-metal (or metal-hard) load bearing surfaces of hip arthroplasties are subjected to fretting crevice corrosion (FCC, one form of MACC). Current work in tribocorrosion involves large contact area tests with multiple asperities, with a distribution of load and wear that changes over time. A more systematic and controlled study of the FCC micro- and nanomechanics is needed.

Therefore, the goal of this …

Graphene Oxide-Thermoplastic Nanocomposites: Fabrication And Properties, Seyedeh Mastooreh Seyedi Ghezghapan

All Dissertations

Polymer nanocomposites are used for a wide variety of applications. These nanocomposites can have a number of important characteristics depending on the nature of the nanomaterial, its size, volume fraction, its distribution, and interactions within the host polymer. Mechanical strength, thermal and electrical conductivity are some of these materials' most focused and studied features. Besides the positive influences of the reinforcements, nanomaterials also might have some adverse impacts on the polymer matrix. These issues could arise from the aggregation of the fillers and the poor interfacial interactions of the components. Several approaches are introduced to modify the nanofillers and enhance …

Modeling Damage Spread, Assessment, And Recovery Of Critical Systems, Justin Burns

Graduate Theses and Dissertations

Critical infrastructure systems have recently become more vulnerable to attacks on their data systems through internet connectivity. If an attacker is successful in breaching a system’s defenses, it is imperative that operations are restored to the system as quickly as possible. This thesis focuses on damage assessment and recovery following an attack. A literature review is first conducted on work done in both database protection and critical infrastructure protection, then the thesis defines how damage affects the relationships between data and software. Then, the thesis proposes a model using a graph construction to show the cascading affects within a system …

Junction Temperature Estimation Of Silicon Carbide Power Module Using Internal Gate Resistance As Temperature Sensitive Electrical Parameter, Michael Sykes

Graduate Theses and Dissertations

The junction temperature of a power module is measured non-intrusively and uninterrupted in its application by analyzing the dependency of gate resistance to temperature. The circuit configuration proposed consists of altering the gate loop path and adding a basic peak detection circuit with an added low-pass filter to accurately measure the small differences seen during a temperature change on the internal gate resistance. The testing on this Silicon Carbide power module shows that the internal gate resistance has a positive temperature coefficient. This causes the current and the voltage drop on the gate loop sensing resistance to reduce as the …

Structural Checking Tool Restructure And Matching Improvements, Derek Taylor

Graduate Theses and Dissertations

With the rising complexity and size of hardware designs, saving development time and cost by employing third-party intellectual property (IP) into various first-party designs has become a necessity. However, using third-party IPs introduces the risk of adding malicious behavior to the design, including hardware Trojans. Different from software Trojan detection, the detection of hardware Trojans in an efficient and cost-effective manner is an ongoing area of study and has significant complexities depending on the development stage where Trojan detection is leveraged. Therefore, this thesis research proposes improvements to various components of the soft IP analysis methodology utilized by the Structural …

Low-Latency And Fresh Content Provision In Information-Centric Vehicular Networks, Shan Zhang, Junjie Li, Hongbin Luo, Jie Gao, Lian Zhao, Xuemin Sherman Shen

Electrical and Computer Engineering Faculty Research and Publications

In this paper, the content service provision of information-centric vehicular networks (ICVNs) is investigated from the aspect of mobile edge caching, considering the dynamic driving-related context information. To provide up-to-date information with low latency, two schemes are designed for cache update and content delivery at the roadside units (RSUs). The roadside unit centric (RSUC) scheme decouples cache update and content delivery through bandwidth splitting, where the cached content items are updated regularly in a round-robin manner. The request adaptive (ReA) scheme updates the cached content items upon user requests with certain probabilities. The performance of both proposed schemes are analyzed, …

Modeling Metastasis In Breast Cancer Patients Using Ehr Data, The Area Deprivation Index (Adi), And Machine Learning Models, Vishesh Patel

McKelvey School of Engineering Graduate Student Theses & Dissertations

Applying machine learning and statistical analysis on traditionally informatics problems is a growing area of research that can result in clinicians being better-able to predict disease outcomes and create more personalized levels of care. In this study, several machine learning models are used to model the likelihood of metastasis in breast cancer patients using a mix of data from the electronic health record and socioeconomic information derived from the Area Deprivation Index (ADI). Metastasis is a late-stage disease progression in a cancer diagnosis where a tumor spreads from its initial development point to another part of the body. In breast …

Application Of Lanthanides In Wastewater Treatment And Water Reuse, George William Kajjumba

UNLV Theses, Dissertations, Professional Papers, and Capstones

Much of the world’s population feed on grains (wheat, rice, and corn). Corn is as sensitive as it is productive. This thirsty, fast-growing plant goes into thermal shock in drought. In 2014, California lost over $2.2 billion in crop production due to drought. The Horn of Africa (in 2011) and Sahel (in 2012) faced humanitarian disasters due to food and water scarcity. The higher frequency of climate change and the erratic nature of rain, combined with underlying economic and social vulnerabilities, has meant that food and water scarcity is here to stay. To improve food and water scarcity, water reclamation …

A Wearable Electronic Monitoring Device For Low Pressure Garment Applications And Temperature Analysis For Prevention Of Ulceration And Infection, Francisco Mata Carlos

UNLV Theses, Dissertations, Professional Papers, and Capstones

The healing process of several medical conditions related to venous insufficiency and burn scar management can be improved by the proper application of pressure. Current practices for applying pressure to an extremity do not guarantee the consensus ideal interface pressures for such medical conditions. Applying a low pressure range (within 15 – 40 mm Hg) is challenging due to many factors, but especially because the actual pressure applied by a compression garment used on a patient is unknown. The proposed device, used to sense and display low pressure values, is described in detail throughout the chapters of this thesis.An electronic …

Efficient Networks-On-Chip Communication Support Solutions For Deep Neural Network Acceleration, Binayak Tiwari

UNLV Theses, Dissertations, Professional Papers, and Capstones

The increasing popularity of deep neural network (DNN) applications demands high computing power and efficient hardware accelerator architectures. DNN accelerators use a large number of processing elements (PEs) and on-chip memory for storing weights and other parameters. A significant challenge is faced when designing a many-core DNN accelerator to handle the data movement between the processing elements. As the communication backbone of a DNN accelerator, networks-on-chip (NoC) plays an important role in supporting various dataflow patterns and enabling processing with communication parallelism in a DNN accelerator. However, the widely used mesh-based NoC architectures inherently cannot efficiently support many-to-one (gather) and …

Predicting The Progression Of Diabetes Mellitus Using Dynamic Plantar Pressure Parameters, Mathew Sunil Varre

UNLV Theses, Dissertations, Professional Papers, and Capstones

Introduction: Diabetic peripheral neuropathy is one of the common complications of type-2 diabetes mellitus (DM). Changes in the intrinsic plantar tissue coupled with repetitive mechanical loads and loss of sensation may lead to foot related complications (skin break down, ulcerations, and amputations) in persons with neuropathy if left untreated. The purpose of this dissertation was to stratify individuals with pre-diabetes, diabetes with and without neuropathy using dynamic plantar pressure parameters during walking, using machine learning algorithms.Methods: Plantar pressure data was collected from one hundred participants during walking with pressure measuring insoles fixed between the feet and thin socks. Simultaneously high-definition …

Contaminants Of Emerging Concern Behavior Within Water Renewal Facilities, Joshua C. Baker

Boise State University Theses and Dissertations

Emerging constituents (ECs), also called contaminants of emerging concern (CECs) are defined by the United States Environmental Protection Agency (U.S.EPA) as: “…pharmaceuticals and personal care products.” This also includes per- and polyfluoroalkyl substances (PFAS), which are used in waterproofing and non-stick cooking products. It is highly likely that regulatory limits will be placed on many ECs because they tend to accumulate in the environment and biological tissues with little to no transformation. ECs pose a threat to the ecological systems of our nation and the fundamental need for clean water by all life on earth. Clean water is essential for …

Biofidelic Considerations For Improving Standardized Airflow And Firmness Testing For Infant Sleep Products, Wyatt D. Davis

Boise State University Theses and Dissertations

Background

Over the last 30 years, 83 infant fatalities (113 reported, 30 incidental) directly involving crib bumpers have been reported to the Consumer Product Safety Commission. Of these reports, 90% are for infants under a year old, with 61% occurring for infants between 1 and 4 months of age (Safety, 2020). There are currently a few regulations governing the design of crib bumper products, but none test the suffocation risk associated with these products using biofidelic methods.

Goals

We sought to explore the development of new testing methods that can determine the safety of different products and are physiologically representative …

Experimentation Of Abrasion Erosion At High Temperature For Concentrated Solar Power Systems, Tessa Mei-Lin Fong

Boise State University Theses and Dissertations

Concentrated solar power (CSP) is an alternative and sustainable way to produce energy. Studies have shown that running these plants at high temperatures above 700°C can increase the thermal efficiency in heat transfer. Molten salt is usually used as the heat transfer medium but cannot be used due to its low maximum temperature and high freezing point. Running these plants at high temperature brings up the concern of erosion and oxidation. Abrasion erosion occurs through the interaction of particles and material. The goal of this research is to understand material degradation due to abrasion erosion to understand the durability of …

Additive Manufacturing Of Sensors For Extreme Environments, Kiyo Tiffany Fujimoto

Boise State University Theses and Dissertations

Advanced manufacturing based direct-write technologies have emerged as the predominant enabler for the fabrication of active and passive sensors for use in harsh operating environments. The ability to directly write and integrate electronic components onto physical packaging can be achieved with additive manufacturing (AM) methods such as direct write technologies (DWT) which include aerosol jet printing (AJP), Ink Jet Printing (IJP), Plasma Jet Printing (PJP), and Micro-Dispense Printing (MDP). In this work, we investigate the use of these methods to accelerate, modernize, and enhance the functionality of sensors and instrumentation to achieve the goal of improving the safety and efficiency …

Rapid, Reliable Tissue Fractionation Algorithm For Commercial Scale Biorefineries, Rahul Reddy Kancharla

Boise State University Theses and Dissertations

Increasing demand, limited supply, and the impact on the environment raise significant concerns about the consumption of fossil fuels. Because of this, global economies are facing two significant energy challenges: i) securing the supply of reliable and affordable energy and ii) achieving the transformation to a low-carbon, high-efficiency, and sustainable energy system. Recently, there has been growing interest in developing portable transportation fuels from biomass in order to reduce the petroleum consumption in the transportation sector - a major contributor to greenhouse gas emission. A cost-effective conversion process to produce biofuels from lignocellulosic biomass material relies not just on the …

Millimeter-Wave Channel Measurements In Airport Environment, Mahfuza Khatun

Boise State University Theses and Dissertations

The wide spectrum available at millimeter-wave (mmWave) bands promises very high data rates and has been proposed as an attractive solution to provide high-speed and reliable wireless communication. Further, there are various potential usages of mmWave technology in transportation, aviation, autonomous vehicles, robotics, etc. Specifically, it is anticipated that automation through this technology will affect and improve the operations in every phase in airport environments. Consequently, the extended autonomous capabilities at airports will generate and consume more information and increase the demand for robust data transfer, which requires larger data rates than ever before. Hence, mmWave frequency, due to its …

Design And Analysis Of Beam Steering Antennas For Next-Generation Wireless Communication, Shafaq Kausar

Boise State University Theses and Dissertations

Reconfigurable antennas have gained immense interest since the last few decades. Reconfigurable antennas can steer beams dynamically in response to the signal environment, they can also support multiple simultaneous beams. This research work aims to make considerable advancements in the design and analysis of low cost and low power beam steerable antennas. It focuses on the design and demonstration of several prototypes with advanced functionalities, such as passive (broadband, multi-beam, shapable beams) and active (electronically reconfigurable) antennas. The first part of this dissertation covers the design and development of passive metamaterial based multibeam antenna at 30 GHz. Designed antenna is …

Electrochemical Impedance Spectroscopy Of Zirconium Oxidation For In-Situ Nuclear Sensing Applications, Michael Andrew Reynolds

Boise State University Theses and Dissertations

To meet the ever-growing energy demands of the modern world, alternative forms of producing power are necessary, and the field of nuclear engineering holds promise to answer this call. Nuclear fuel cladding in light water reactors (LWRs) currently draws a large amount of attention from scientists and researchers, as it provides many challenges to design around. Since the 1950s, zirconium and its protective oxide layer have been utilized as an effective material for the task, possessing good mechanical strengths, high corrosion resistance, and a low neutron absorption cross section. Despite these beneficial properties, however, fuel cladding remains vulnerable to several …

Understanding The Radiation Effects On Fiber Optic Sensors, Sohel Rana

Boise State University Theses and Dissertations

In this dissertation, the effects of radiation (gamma, neutron or mixed gamma and neutron) on optical fiber sensors are studied and new techniques for real-time measurement of radiation-induced macroscopic changes in optical fibers are presented. It is crucial among the research and development efforts in the nuclear energy field to conduct experiments in Advanced Test Reactor (ATR) to support lifetime extension, novel fuels and materials development, better fuel management, and enhanced safety of existing as well as future nuclear power plants (NPP). Due to their unparalleled and unique advantages over traditional sensors, optical fiber sensors are deemed potential candidates for …