Engineering Commons^™

Polyvinyl Chloride Gels: Theoretical Modeling Of Their Actuation Mechanism And Characterization Of Their Properties, Zachary Frank

UNLV Theses, Dissertations, Professional Papers, and Capstones

Polyvinyl chloride (PVC) gels are an electroactive polymer smart material which has been considered in a variety of actuator applications. Their large deformation, fast response rates, optical transparency, and soft nature has made them a key area of interest in fields ranging from soft robotics to optics. PVC gels are made from PVC mixed with large quantities of plasticizer, such as dibutyl adipate (DBA). When a voltage is applied, the gel experiences an “anodophilic” deformation (in which it moves preferentially towards the anode). This unique characteristic is the result of a charge buildup near the anode surface, which creates electromechanical …

Improving Pedestrian Safety With The Implementation Of The Demand-Responsive Transverse Rumble Strip As A New Traffic Safety Countermeasure, Md Shakhawat Hossen

UNLV Theses, Dissertations, Professional Papers, and Capstones

The traditional TRS has been extensively used as a traffic calming device to provide cognitive alerts in the form of sound and vibration to drivers. However, TRS always remains fixed on the road and thus exerts cognitive alerts, irrespective of any potential downstream hazards. Moreover, the continuous exposure to rumble strips has been identified as a source of discomfort and annoyance for drivers, which limits its application to potentially useful scenarios. This study explores a rumble strip design with dynamic behavior named as Demand-Responsive Transverse Rumble Strip (DRTRS) in order to address the limitations of static TRS. The study incorporates …

A Human-Embodied Drone For Dexterous Aerial Manipulation, Dongbin Kim

UNLV Theses, Dissertations, Professional Papers, and Capstones

Current drones perform a wide variety of tasks in surveillance, photography, agriculture, package delivery, etc. However, these tasks are performed passively without the use of human interaction. Aerial manipulation shifts this paradigm and implements drones with robotic arms that allow interaction with the environment rather than simply sensing it. For example, in construction, aerial manipulation in conjunction with human interaction could allow operators to perform several tasks, such as hosing decks, drill into surfaces, and sealing cracks via a drone. This integration with drones will henceforth be known as dexterous aerial manipulation.

Our recent work integrated the worker’s experience into …

Quaternary Ammonium Compounds As Precursors To Disinfection Byproducts, Padmanabhan Krishnaswamy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Disinfection of drinking water is crucial for providing a safe potable water supply. Some of the most common disinfectants employed are chlorine, chloramines and ozone. While these disinfectants successfully inactivate pathogenic microorganisms, they simultaneously react with inorganic or organic precursors to form toxic byproducts, most commonly referred to as disinfection byproducts (DBPs). While there is a wide variety of organic matter and disinfection byproducts known, in this study we have looked into the potential of certain quaternary ammonium compounds (QACs) to act as precursors to form DBPs, namely trihalomethanes (THMs), haloacetonitriles (HANs) and nitrosamines.

The ubiquitous nature of QACs in …

Computational Sodium Heat Pipe Simulation In Three Dimensions For Transient Nuclear Reactor Analysis With Variable Surface Heat Flux, Valerie Jean Lawdensky

UNLV Theses, Dissertations, Professional Papers, and Capstones

Heat pipes are used to transfer heat through phase change in a liquid/vapor contained in a metal tube. They are passive devices that require no pumps to circulate the fluid and can transfer heat far more efficiently than a solid copper rod of the same diameter. They are commonly used in laptop computers where copper heat pipes filled with water take heat away from the CPU and transfer the heat to air through a heat exchanger. Heat pipes were also used in the Kilopower nuclear reactor where higher temperatures required sodium as the working fluid with stainless steel tubes. Computer …

Factors Influencing Service Robot Adoption: A Comparative Analysis Of Hotel-Specific Service Robot Acceptance Models, Ying Dong

UNLV Theses, Dissertations, Professional Papers, and Capstones

The market for service robots is expected to expand significantly owing to the increasing relevance of service automation under the outbreak of the COVID-19 pandemic. Despite the growing managerial interest in robotic applications in the hotel industry, current robotic research has been mostly conceptual with limited robot data on hand. In light of this issue, this paper will conduct a comparative analysis of hotel-specific service robot acceptance models between the Service Robot Acceptance Model (sRAM) and the Service Robot Integration Willingness (SRIW) framework. By identifying key elements of each service robot acceptance model, this paper puts an emphasis on investigating …

Material Handling With Embodied Loco-Manipulation, Jean Chagas Vaz

UNLV Theses, Dissertations, Professional Papers, and Capstones

Material handling is an intrinsic component of disaster response. Typically, first responders, such as firefighters and/or paramedics, must carry, push, pull, and handle objects, facilitating the transportation of goods. For many years, researchers from around the globe have sought to enable full-sized humanoid robots to perform such essential material handling tasks. This work aims to tackle current limitations of humanoids in the realm of interaction with common objects such as carts, wheelbarrows, etc. Throughout this research, many methods will be applied to ensure a stable Zero Moment Point (ZMP) trajectory to allow a robust gait while loco-manipulating a cart. The …

Customer Purchase Intention Towards The Us Airline, Ming-Chun Kuo

UNLV Theses, Dissertations, Professional Papers, and Capstones

The airline industry has become the main economic resource to the United States. The airline companies have had a very mature operating base towards their marketing standing point and their target customers. Yet, customer purchase behavior has changed consistently, especially after the whole year of lockdown of COVID-19 pandemic. Customers no longer only look for the service quality when they select an airline to fly. This paper aims to explore the possible aspects that may affect customer purchase intention to a US-based airline. Many studies have indicated that service quality is no longer the only reason to attract the purchase …

Tinyml For Gait Stride Classification, Priyanka Rajendra

UNLV Theses, Dissertations, Professional Papers, and Capstones

Human gait classification and analysis become very important when a person has been diagnosed with a neurological disorder or has suffered an injury which has affected their ability to walk correctly. Gait strides are an important parameter to be studied as it helps the doctor to diagnose any underlying gait condition and evaluate what type of treatment suits the best for the patient’s recovery. Studying gait strides also helps athletes to improve their performance.In today’s world, machine learning has emerged as one of the most widely used technology for classification and analysis of gait characteristics. TinyML is a field of …

Designs And Outcomes Of Transcranial Magnetic Stimulation (Tms) And Repetitive Transcranial Magnetic Stimulation (Rtms) Circuits, Daniel Senda

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis reports the design and outcomes of several circuits intended for transcranial magnetic stimulation (TMS) and repetitive transcranial magnetic stimulation (rTMS) research. In simple terms, TMS circuits are composed of four main blocks: high voltage power source, energy storage bank, control switch, and coil. Each one of these blocks has characteristics that influence how well the circuit will perform for TMS procedures. A successful TMS research circuit must have the ability to emit controlled electromagnetic pulses through a coil connected to it. For the first block, voltages ranging from 50 V to 2 kV were used. In the second …

Modeling The Mechanical Behavior And Shock Propagation Of Metallic And Nanocomposite Materials, Pouya Shojaeishahmirzadi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Evaluating the materials properties under different loading conditions is critical in various industries. Compared to quasi-static loading, predicting the behavior of structures under dynamic loads is more challenging. In this work, we will address multiple problems with strain rates varying from quasi-static to hypervelocity conditions. Computer simulation is increasingly used in the design and evaluation phases to improve the efficiency, cost-effectiveness, and flexibility. However, verification and validation of each simulation is necessary. Experiments are performed in all topics and the computational models are validated by comparing with the experiments. One of the most common types of connections in structures is …

Rotten With Prediction, Serena Raquel Hicks

UNLV Theses, Dissertations, Professional Papers, and Capstones

This project focuses on the relationship between religion and technology as it is portrayed in Science Fiction (SF). This thesis explores the SF genre rhetorically by examining the 2002 movie Minority Report (MR), which signaled the importance of surveillance and the need to predict future crimes following 9/11. The events of 9/11 played a significant role in post 9/11 SF films, which reflect and critique our communal and cultural values. 9/11 created a new relationship between the U.S justice system, predictive technologies (PTs), and data gathering. Through the Bush Doctrine of “preemptive action,” the U.S government attempted to use Dataism, …

Relationship Between Standardization Critical Success Factors (Csfs) And Project Performance, Binit Kumar Shrestha

UNLV Theses, Dissertations, Professional Papers, and Capstones

Facility standardization strategy is defined as the development and use of consistent designs to align project stakeholders, objectives, and scope to capture and optimize schedule, cost, and value. The implementation and proper execution of this strategy can lead to considerable benefits, such as design once and reuse multiple times, along with learning curve benefits in fabrication, operations, and construction, as well as accelerated responds to schedule needs. Although standardization strategy is not a new idea; capital projects have failed to achieve high levels of facility standardization. The primary reason for this is the industry’s struggle to execute standardized projects successfully. …

Biotransformation Of Trace Organic Compounds Via Microbial Ammonia Oxidation In Biofiltration Systems For Water Reuse, Nicholas Babcock

UNLV Theses, Dissertations, Professional Papers, and Capstones

The use of ozone-biofiltration (BAF) for water reuse has recently been viewed as an attractive option due its low cost and ability to achieve high quality effluent. However, one challenge that is particularly problematic for ozone-biofiltration is the occurrence of trace organic compounds (TOrCs), such as pharmaceuticals and personal care products, in domestic wastewater, primarily due to their uncertain public health impacts. These TOrCs might be degraded by three ammonia oxidizing microorganisms (AOMs), including ammonia oxidizing bacteria (AOBs), ammonia oxidizing archaea (AOAs), and Comammox that have been found in biofiltration systems. Cometabolism, the fortuitous biodegradation of compounds by enzymes used …

Analysis Of Microscopic Objects Using Computer Vision Methods, Yuan Dao

UNLV Theses, Dissertations, Professional Papers, and Capstones

As an essential and powerful tool to observe living organisms, three-dimensional fluorescence microscopy is widely used in biological research and diagnosis. The 4D fluorescence microscopy data can be obtained using time-lapsed videos of 3D images. To analyze and extract useful information from the increasingly large and complex biological image dataset, efficient and effective computational tools are in need but still lagging behind. In analyzing biological data, two major challenges are faced. First, time-lapsed fluorescence microscopic images typically have a low SNR. Second, biological objects often change their morphology and internal structure frequently. As such, conventional image processing methods may not …

Forecasting Pedestrian Trajectory Using Deep Learning, Arsal Syed

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this dissertation we develop different methods for forecasting pedestrian trajectories. Complete understanding of pedestrian motion is essential for autonomous agents and social robots to make realistic and safe decisions. Current trajectory prediction methods rely on incorporating historic motion, scene features and social interaction to model pedestrian behaviors. Our focus is to accurately understand scene semantics to better forecast trajectories. In order to do so, we leverage semantic segmentation to encode static scene features such as walkable paths, entry/exits, static obstacles etc. We further evaluate the effectiveness of using semantic maps on different datasets and compare its performance with already …

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 …

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 …

Healthy Aging In Place: An Integrated Smart Home Using Alexa-Compatible Technology, Tyler Kryst

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this research was to address current healthcare concerns among the aging population. Around the globe, the average life expectancy is projected to continue increasing resulting in a higher prevalence of age-related disease. With the ever-increasing capabilities of modern technology, it is necessary to apply this technology to increase the health and safety of older adults. This work had three objectives. The first objective was the establishment of an integrated smart home aimed at creating a healthy aging-in-place environment through the use of Alexa. The second objective was the development and integration of a completely custom health device …

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 …

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 …

Infants' Facial Emotion Recognition, Umme Fatema

UNLV Theses, Dissertations, Professional Papers, and Capstones

Facial Emotion Recognition (FER) has become a popular computer vision topic and attracted a lot of researchers. However, these researches mostly focus on adult facial emotion. Infants’ facial structure and expression of emotions differ from adults’. That is why our target is to create a model that particularly focuses on infants’ facial emotions. In this work, we classify three types of emotions: positive, negative, and neutral. Two datasets are used in this work. One is an image-based dataset named ‘The City’ that consists of 154 images of infants aged 0-12 months. Another is the Rebel Dataset from the Department of …

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 …

Geometric Quality Assessment Of A Modular House Using Bim And Photogrammetric Point Clouds, Preetam Kapsikar

UNLV Theses, Dissertations, Professional Papers, and Capstones

As-built documentation of modular structures is an important set of records for a project, that consist of construction drawings and specifications, project design modifications, prefabrication, and component assembly. In particular, manual geometric quality assessments of a structure’s prefabricated components are generally fraught with errors, making it extremely difficult to compare the as-built construction with the specified drawings, which affects the project. Furthermore, if the prefabricated components are manufactured with errors, this can result in construction schedule delays and high additional costs due to rework. Several technologies, such as point cloud data generated using laser sensors and LiDAR, have been developed …

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 …

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 …