Engineering Commons^™

Electron Paramagnetic Resonance Study Of Neutral Mg Acceptors In Β-Ga2O3 Crystals, Brant E. Kananen, Larry E. Halliburton, Elizabeth M. Scherrer, K. T. Stevens, G. K. Foundos, K. B. Chang, Nancy C. Giles

Faculty Publications

Electron paramagnetic resonance (EPR) is used to directly observe and characterize neutral Mg acceptors (Mg⁰_Ga) in a β-Ga₂O₃ crystal. These acceptors, best considered as small polarons, are produced when the Mg-doped crystal is irradiated at or near 77 K with x rays. During the irradiation, neutral acceptors are formed when holes are trapped at singly ionized Mg acceptors (Mg−Ga). Unintentionally present Fe³⁺ (3d⁵) and Cr³⁺ (3d³) transition-metal ions serve as the corresponding electron traps. The hole is localized in a nonbonding p orbital on a threefold-coordinated oxygen ion …

On-Chip, High-Sensitivity Temperature Sensors Based On Dye-Doped Solid-State Polymer Microring Lasers, Lei Wan, Hengky Chandrahalim, Cong Chen, Qiushu Chen, Ting Mei, Yuji Oki, Naoya Nishimura, Lingjie Jay Guo, Xudong Fan

Faculty Publications

We developed a chip-scale temperature sensor with a high sensitivity of 228.6 pm/°C based on a rhodamine 6G (R6G)-doped SU-8 whispering-gallery mode microring laser. The optical mode was largely distributed in a polymer core layer with a 30 μm height that provided detection sensitivity, and the chemically robust fused-silica microring resonator host platform guaranteed its versatility for investigating different functional polymer materials with different refractive indices. As a proof of concept, a dye-doped hyperbranched polymer (TZ-001) microring laser-based temperature sensor was simultaneously developed on the same host wafer and characterized using a free-space optics measurement setup. Compared to TZ-001, the …

Specification Of Mixed Logit Models Using An Optimization Approach, Cristian David Arteaga Sanchez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Mixed logit models are a widely-used tool for studying discrete outcome problems. Modeling development entails answering three important questions that highly affect the quality of the specification: (i) what variables are considered in the analysis? (ii) what are going to be the coefficients for these variables? and (iii) what density function these coefficients will follow? The literature provides guidance; however, a strong statistical background and an ad hoc search process are required to obtain the best model specification. Knowledge of the problem context and data is required. Given a dataset including discrete outcomes and associated characteristics the problem to be …

Remote Sensing Of The Environmental Impacts Of Utility-Scale Solar Energy Plants, Mohammad Masih Edalat

UNLV Theses, Dissertations, Professional Papers, and Capstones

Solar energy has many environmental benefits compared with fossil fuels but solar farming can have environmental impacts especially during construction and development. Thus, in order to enhance environmental sustainability, it is imperative to understand the environmental impacts of utility-scale solar energy (USSE) plants. During recent decades, remote sensing techniques and geographic information systems have become standard techniques in environmental applications. In this study, the environmental impacts of USSE plants are investigated by analyzing changes to land surface characteristics using remote sensing. The surface characteristics studied include land cover, land surface temperature, and hydrological response whereas changes are mapped by comparing …

Optimization Of Prosthetic Hands: Utilizing Modularity To Improve Grip Force, Grasp, And Versatility, Jordan William Harris

UNLV Theses, Dissertations, Professional Papers, and Capstones

It has been demonstrated that although many varieties of upper limb prosthetics exist, commercially available prosthetics are outdated and unsatisfactory. Ineffectiveness and limitations have led to some prosthesis wearers having to own multiple devices, whereas others have given up on them entirely. Even though ample research has been conducted to design and test new hand designs, the industry appears to rest in an overall stagnated state.

It was proposed here, that one problem with prosthetic research is an excess of variables involved in testing, and therefore the improper application of the scientific method. It seems that each time a research …

Evaluation Of The Properties Of Rubberized Asphalt Binders And Mixtures, Kazem Jadidirendi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Rubber modified binder samples are tested and evaluated based on SHRP requirements. Best rubber content is suggested for modifying binder. Rubber modified asphalt mixtures were manufactured and tested. Based on Hveem stability and volumetric properties of asphalt mixtures, optimum binder content is evaluated and reported. Performance properties of asphalt mixtures made with various rubber size and method were analyzed and compared. An ultrasound measurement performed on asphalt mixture samples and the results were analyzed. It is discovered that rubber improves asphalt viscosity and resistance to rutting deformation. Rubber also increases asphalt’s dynamic modulus.

Meshless Method For Simulation Of Compressible Flow, Ebrahim Nabizadeh Shahrebabak

UNLV Theses, Dissertations, Professional Papers, and Capstones

In the present age, rapid development in computing technology and high speed supercomputers has made numerical analysis and computational simulation more practical than ever before for large and complex cases. Numerical simulations have also become an essential means for analyzing the engineering problems and the cases that experimental analysis is not practical. There are so many sophisticated and accurate numerical schemes, which do these simulations. The finite difference method (FDM) has been used to solve differential equation systems for decades. Additional numerical methods based on finite volume and finite element techniques are widely used in solving problems with complex geometry. …

Sparse Mri And Ct Reconstruction, Ali Pouryazdanpanah Kermani

UNLV Theses, Dissertations, Professional Papers, and Capstones

Sparse signal reconstruction is of the utmost importance for efficient medical imaging, conducting accurate screening for security and inspection, and for non-destructive testing. The sparsity of the signal is dictated by either feasibility, or the cost and the screening time constraints of the system. In this work, two major sparse signal reconstruction systems such as compressed sensing magnetic resonance imaging (MRI) and sparse-view computed tomography (CT) are investigated.

For medical CT, a limited number of views (sparse-view) is an option for whether reducing the amount of ionizing radiation or the screening time and the cost of the procedure. In applications …

Improving Pattern Recognition And Neural Network Algorithms With Applications To Solar Panel Energy Optimization, Ernesto Zamora Ramos

UNLV Theses, Dissertations, Professional Papers, and Capstones

Artificial Intelligence is a big part of automation and with today's technological advances, artificial intelligence has taken great strides towards positioning itself as the technology of the future to control, enhance and perfect automation. Computer vision includes pattern recognition and classification and machine learning. Computer vision is at the core of decision making and it is a vast and fruitful branch of artificial intelligence. In this work, we expose novel algorithms and techniques built upon existing technologies to improve pattern recognition and neural network training, initially motivated by a multidisciplinary effort to build a robot that helps maintain and optimize …

Laser As A Tool To Study Radiation Effects In Cmos, Bahar Ajdari

Dissertations and Theses

Energetic particles from cosmic ray or terrestrial sources can strike sensitive areas of CMOS devices and cause soft errors. Understanding the effects of such interactions is crucial as the device technology advances, and chip reliability has become more important than ever. Particle accelerator testing has been the standard method to characterize the sensitivity of chips to single event upsets (SEUs). However, because of their costs and availability limitations, other techniques have been explored. Pulsed laser has been a successful tool for characterization of SEU behavior, but to this day, laser has not been recognized as a comparable method to beam …

Fluid Manipulations Using A Piezo Electric Transformer For Sensing And Spray Generation Applications, Zeinab Ramshani

Dissertations

A steady effort has been made on the development of fluid manipulation techniques for sensing and actuating systems. Conventional techniques of fluid manipulation for sensing and spray generation purposes, often need trained staff or high input power and they are complicated, time consuming and expensive. Therefore, it is necessary to develop new systems which can overcome these drawbacks.

In this dissertation, the author has developed piezoelectric-based systems for fluid manipulation. The focus of this dissertation involves novel approaches of enhancing the sensing and actuating systems using the piezoelectric devices. This includes designing a system, which theoretically can overcome the limitations …

Integrity Coded Databases: Ensuring Correctness And Freshness Of Outsourced Databases, Ujwal Karki

Boise State University Theses and Dissertations

In recent years, cloud storage has become an inexpensive and convenient option for individuals and businesses to store and retrieve information. The cloud releases the data owner from the financial burden of hiring professionals to create, update and maintain local databases. The advancements in the field of networking and the growing need for computing resources for various applications have made cloud computing more demanding. Its positive aspects make the cloud an attractive option for data storage, but this service comes with a cost that it requires the data owner to relinquish control of their information to the cloud service provider. …

The Mechanism Of Radiation-Induced Nanocluster Evolution In Oxide Dispersion Strengthened And Ferritic-Martensitic Alloys, Matthew John Swenson

Boise State University Theses and Dissertations

The objective of this study is to evaluate the mechanism of irradiation-induced nanoparticle evolution in a model Fe-9%Cr oxide dispersion strengthened steel and commercial ferritic-martensitic alloys HCM12A and HT9. Each alloy is irradiated with Fe²⁺ ions, protons, or neutrons to doses ranging from 1-100 displacements per atoms at 500°C. The morphology of nanoclusters are characterized using atom probe tomography. The evolution of clusters in each alloy are notably different with each irradiating particle, and the competing effects of ballistic dissolution and radiation-enhanced, diffusion-driven growth are attributed to the respective differences in cluster evolution. A phase evolution model, originally theorized …

Feasibility Of Melville Marginalia Authorship Differentiation, Aaron Burdin

Boise State University Theses and Dissertations

We examine the feasibility of using image processing techniques to determine differentiation in authorship of historical pencil marks. Pencil marks with unattributed and attributed authorship are segmented from digital images of historical books. Analysis is performed on five features that are extracted from the "vertical" pencil marks, with those features used as a basis for authorship of marks. These marks consist of single stroke marks that are interspersed in the same document. We describe the challenges of the digital format that we were given and the steps taken in using autonomous segmentation to save pixel locations of marks. Five mark …

Development And Application Of Hydraulic And Hydrogeologic Models To Better Inform Management Decisions, Trinity L. Stout

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Water is one of the most important and limited resources in regions with little rainfall. As populations continue to grow, so does the need for water. Individuals in water management positions need to be well informed in order to avoid potential negative effects concerning the overall quality and amount of water available for both people and the environment. In order to provide better information for these individuals, computer models and mathematical relationships are commonly developed to estimate the outcome of different situations regarding surface water and groundwater. Along these lines, this study focused on two modeling studies that provide information …

Heat Transfer Analysis Of Localized Heat-Treatment For Grade 91 Steel, Jacob D. Walker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many of the projects utilizing Grade 91 steel are large in scale, therefore it is necessary to assemble on site. The assembly of the major pieces often requires welding in the assembly; welding drastically changes the superior mechanical properties of Grade 91 steel that it was specifically developed for. Therefore, because of the adverse effects of welding on the mechanical properties of Grade 91, it is necessary to do a localized post weld heat treatment.

In this study a localized post weld heat treatment is used to gather experimental data. The data is then used to derive unknown heat transfer …

Resolving Spatial And Temporal Variability In Dissolved Organic Matter Characteristics Within Combined Agricultural And Stormwater Conveyances, Bryce A. Mihalevich

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In many urban areas, stormwater runoff can threaten the ecological health of streams and downstream water bodies. Due to the increased impervious nature of urban landscapes, runoff is more “flashy” and as a result, high concentrations of pollutants can be transported in shorter periods of time than in more natural environments. One pollutant of concern is dissolved organic matter (DOM). DOM is important within aquatic ecosystems, but excess amounts can cause depletion in dissolved oxygen concentrations and can negatively affect aquatic organisms. This study investigated changes in DOM quantity and sources within the Northwest Field Canal (NWFC), an urban water …

Peptoid-Based Microsphere Coatings For Use As Tunable Biocompatible Interfaces, German Raul Perez Bakovic

Graduate Theses and Dissertations

The pursuit of sensitive, non-invasive, and cost efficient diagnostic tools for early stage disease detection have led to the development of sophisticated biosensor technologies for proteomic studies. As these markers increase in complexity, the role of support substrates grows increasingly important. Limitations in existing support substrates include the potential for increased sensitivity, binding specificity, and bio-stability. Ideal support substrates need to provide biocompatible and bioresistant surfaces, that offer high surface areas for binding, and enables the incorporation of diverse chemistries. The use of peptoids as the basis for the deposition of uniform microsphere coatings offers a mean to the attainment …

Thermoelectric System Modeling And Design, Buddhima Pasindu Gamarachchi

Boise State University Theses and Dissertations

Thermoelectric generators (TEGs) convert heat to electricity by way of the Seebeck effect. TEGs have no moving parts and are environmentally friendly and can be implemented with systems to recover waste heat. This work examines complete thermoelectric systems, which include the (TEG) and heat exchangers or heat sinks attached to the hot and cold sides of the TEG to maintain the required temperature difference across the TEG. A 1-D steady state model is developed to predict the performance of a TEG given the required temperatures and device dimensions. The model is first validated using a 3-D model and then is …

Subsurface Characterization Of Flexible Pavements Constructed Over Expansive Soil Subgrades And Selection Of Suitable Rehabilitation Alternatives, Kazi Moinul Islam

Boise State University Theses and Dissertations

Expansive soils present significant engineering challenges, with annual costs associated with repairing structures constructed over expansive soils estimated to run into several billion dollars. Volume changes in expansive soil deposits induced by fluctuations in the moisture content can result in severe damage to overlying structures. A flexible pavement section near the Western Border of Idaho has experienced recurrent damage due to volume changes in the underlying expansive soil layer; traditional stabilization methods have provided partial success over the years. The main objective of this research effort was to characterize the problematic soil layer contributing to the recurrent pavement damage and …

Effect Of Particle Size Distribution And Packing Characteristics On Railroad Ballast Shear Strength: A Numerical Study Using The Discrete Element Method, S. M. Naziur Mahmud

Boise State University Theses and Dissertations

Railroad infrastructure plays a significant role in sustaining the economy of a country, and facilitates fast, safe and reliable transportation of passengers as well as commodities. Significant capital investments are required for the construction and maintenance of a railroad network that is structurally and functionally adequate. The ballast layer is one of the main structural components of a conventional rail track system, and comprises coarse-grained unbound particles, often as large as in size. The ballast as a load-bearing layer resists train-induced stresses through particle-particle interaction. Accordingly, particle-size distribution and packing characteristics are important factors that govern the mechanical behavior of …

In Situ Tem Micropillar Compression Testing In Irradiated Oxide Dispersion Strengthened Alloys, Kayla Haruko Yano

Boise State University Theses and Dissertations

The objective of this study is to determine the validity of in situ transmission electron microscopy (TEM) micro-compression of pillars in as received and ion-irradiated Fe-9%Cr oxide dispersion strengthened (ODS) alloy. The growing role of charged particle irradiation in the evaluation of nuclear reactor candidate materials requires the development of novel methods to assess mechanical properties in near-surface irradiation damage layers just a few micrometers thick. In situ TEM mechanical testing is one such promising method, yet size effects must be understood to validate the technique. In this work, a micro-compression pillar fabrication method is developed. Yield strengths measured directly …

Wind Farm Power Prediction In Complex Terrain, Micah Sandusky

Boise State University Theses and Dissertations

There has been increasing interest in predicting the velocity field within wind farms in complex terrain for resource assessment, turbine siting, and power forecasting. These capabilities are made possible by advancements in computational speed from a new generation of computing hardware and numerical methods. The current thesis research focuses on two technical components to advance the current state in wind power forecasting. The first component is improved prediction of wind flow over complex terrain using the versatile immersed boundary method to represent surface boundary conditions on a fixed Cartesian mesh. The proposed approach embodies the law-of-the-wall for rough surfaces and …

Effects Of Intentional Electromagnetic Interference On Analog To Digital Converter Measurements Of Sensor Outputs And General Purpose Input Output Pins, David A. Ware

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As technology becomes more prevalent, its application to safety and security in critical systems continues to increase. This leads to an increased dependence on sensors to provide an accurate view of the environment surrounding an application. These sensors can also be exploited by a malicious individual to attack a system and compromise its safety or security. These attacks change the reported value of a sensor so that it doesn't reflect the real situation. The systems in a car can be used as an example of this. Cars can have numerous sensors that measure a variety of things, including the car's …

Analysis Of Angles-Only Hybrid Space-Based/Ground-Based Approach For Geosynchronous Orbit Catalog Maintenance, Blythe A. Andrews

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Geosynchronous Equatorial Orbit (GEO) is critical to Earth communications, weather monitoring, and national defense. Orbit estimation of GEO objects is difficult due to physical constraints placed on ground-based tracking devices such as weather, object range, and tracking frequency restrictions. These constraints are commonly mitigated through the use of two-way signaling devices for cooperative GEO satellites. However, determining the position and velocity of uncooperative GEO satellites and/or objects is more challenging. The objective of this dissertation is to quantify the increased orbital accuracy of objects in the GEO catalog when the Air Force Space Command Space Surveillance Network (AFSPC SSN) is …

Cell-Free Synthesis Of Proteins With Unnatural Amino Acids: Exploring Fitness Landscapes, Engineering Membrane Proteins And Expanding The Genetic Code, Song Min Schinn

Theses and Dissertations

Unnatural amino acids (uAA) expand the structural and functional possibilities of proteins. Numerous previous studies have demonstrated uAA as a powerful tool for protein engineering, but challenges also remain. Three notable such challenges include: (1) the fitness of uAA-incorporated proteins are difficult to predict and time-consuming to screen with conventional methods, (2) uAA incorporation in difficult-to-express proteins (e.g. membrane proteins such as G-protein coupled receptors) remain challenging, and (3) the incorporation of multiple types of uAA are still limited. In response, we pose cell-free protein synthesis (CFPS), a rapid and versatile in vitro expression system, as a platform to explore …

Performance-Based Liquefaction Triggering Analyses With Two Liquefaction Models Using The Cone Penetration Test, Alex Michael Arndt

Theses and Dissertations

This study examines the use of performance-based engineering in earthquake liquefaction hazard analysis with Cone Penetration Test data (CPT). This work builds upon previous research involving performance-based liquefaction analysis with the Standard Penetration Test (SPT). Two new performance-based liquefaction triggering models are presented herein. The two models used in this liquefaction analysis are modified from the case-history based probabilistic models proposed by Ku et al. (2012) and Boulanger and Idriss (2014). Using these models, a comparison is made between the performance-based method and the conventional pseudo-probabilistic method. This comparison uses the 2014 USGS probabilistic seismic hazard models for both methods. …

Cyclist Detection, Tracking, And Trajectory Analysis In Urban Traffic Video Data, Farideh Foroozandeh Shahraki

UNLV Theses, Dissertations, Professional Papers, and Capstones

The major objective of this thesis work is examining computer vision and machine learning detection methods, tracking algorithms and trajectory analysis for cyclists in traffic video data and developing an efficient system for cyclist counting. Due to the growing number of cyclist accidents on urban roads, methods for collecting information on cyclists are of significant importance to the Department of Transportation. The collected information provides insights into solving critical problems related to transportation planning, implementing safety countermeasures, and managing traffic flow efficiently. Intelligent Transportation System (ITS) employs automated tools to collect traffic information from traffic video data. In comparison to …

Automated Quantification Of White Blood Cells In Light Microscopic Images Of Injured Skeletal Muscle, Yang Jiao

UNLV Theses, Dissertations, Professional Papers, and Capstones

Muscle regeneration process tracking and analysis aim to monitor the injured muscle tissue section over time and analyze the muscle healing procedure. In this procedure, as one of the most diverse cell types observed, white blood cells (WBCs) exhibit dynamic cellular response and undergo multiple protein expression changes. The characteristics, amount, location, and distribution compose the action of cells which may change over time. Their actions and relationships over the whole healing procedure can be analyzed by processing the microscopic images taken at different time points after injury. The previous studies of muscle regeneration usually employ manual approach or basic …

Utilizing Researchgate Social Network By Iranian Engineering, Amir Reza Asnafi, Maryam Rahmani Ma In Knowledge And Information Scienc

Library Philosophy and Practice (e-journal)

This study aimed to assess the role of Researchgate in the development of scientific- scholarly activities among Faculty Members of University of Tehran's Engineering College. This study is Survey and descriptive research and data collection tools, including profiles of researchers at the Researchgate and questionnaire. The study population included faculty members of University of Tehran's Engineering College in 2016 was 242 researcher were earned RG score. The sample 144 subjects who were selected via stratified random sampling method and the questionnaire distributed 144 questionnaires were collected and then Results were analyzed using SPSS software From the perspective of engineering researchers, …