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Spectroscopic Investigation Of The Chemical And Electronic Properties Of Chalcogenide Materials For Thin-Film Optoelectronic Devices, Kimberly Horsley

UNLV Theses, Dissertations, Professional Papers, and Capstones

Chalcogen-based materials are at the forefront of technologies for sustainable energy production. This progress has come only from decades of research, and further investigation is needed to continue improvement of these materials.

For this dissertation, a number of chalcogenide systems were studied, which have applications in optoelectronic devices, such as LEDs and Photovoltaics. The systems studied include Cu(In,Ga)Se2 (CIGSe) and CuInSe2 (CISe) thin-film absorbers, CdTe-based photovoltaic structures, and CdTe-ZnO nanocomposite materials. For each project, a sample set was prepared through collaboration with outside institutions, and a suite of spectroscopy techniques was employed to answer specific questions about the system. These …

Li+ Ion Transport In Select Lithium-Rich Antiperovskites, John William Howard

UNLV Theses, Dissertations, Professional Papers, and Capstones

Lithium-Rich Antiperovskites (LiRAPs) have been shown to possess relatively high ionic conductivity at room temperature, and become superionic conductors at elevated temperatures. These materials generally have a stoichiometry Li3BX, where B is a doubly deficient anion, and X is a monovalent anion. Ideally they belong to the high symmetry space group Pm-3m where lithium atoms occupy octahedral corners, B anions occupy octahedral centers, and X anions occupy the interstitial centers between the octahedra. LiRAPs were synthesized using several different methods and characterized by XRD, EIS, DSC, TGA, FTIR, and INS techniques. Chemical analyses were performed to determine the stoichiometries of …

Spectral Decomposition Of The Scattered Light Due To Deposits On The Solar Panel Surface, And Cross Correlated To Power Loss, Suzanna Ho

UNLV Theses, Dissertations, Professional Papers, and Capstones

The electric energy generated by solar panels declines due to dust particulates, bird deposits, water spots, and other contaminants that inhibit sunlight absorption and promote light scattering. As part of our research, we use cameras to capture images of solar panels, and analyze the images to detect the amount of scattered light. The more scattered light there is, the less light there is to penetrate the solar panel glass and reach the part of the panel that converts incident light to electric energy; therefore, less energy is generated. In this paper, we discuss the classification algorithm we developed to classify …

Modeling And Analysis Of Pedestrian Flows, Romesh Khaddar

UNLV Theses, Dissertations, Professional Papers, and Capstones

According to the Traveler Opinion and Perception Survey of 2005, about 107.4 million Americans regularly use walking as a mode of transport during their commute, which amounts for 51% of the total American population. In 2009, 4092 pedestrian fatalities were reported nationwide, out of 59,000 pedestrian crashes. This amounts for 12% of the fatalities in the total traffic accidents recorded, and shows an over-representation of pedestrians incidents. Thus, it is imperative to understand the causes behind such statistics, and conduct a comprehensive research on pedestrian walking behavior and their interaction with surroundings.

A lot of researches on pedestrian flows have …

Spatial Analysis Of Chipped Stone At The Cypro-Ppnb Site Of Krittou Marottou Ais Giorkis: A Gis-Assisted Study, Levi Lowell Keach

UNLV Theses, Dissertations, Professional Papers, and Capstones

Krittou Marottou Ais Giorkis (`Ais Giorkis) is an Aceramic Neolithic site, occupied approximately 9,500 cal B.P., and located in the western foothills of the Troodos Mountains on the Mediterranean island of Cyprus. This thesis is an intra-site spatial analysis of the chipped stone assemblage recovered between 1997 and 2013 from the site using Geographic Information Systems (GIS) technology. Previous work on the assemblage from 1997 through 2004 had attempted spatial analysis using traditional statistical methods and found no patterning (O'Horo 2008). Using the expanded database and GIS this thesis identifies multiple spatial patterns in the assemblage with implications on the …

Simulation, And Overload And Stability Analysis Of Continuous Time Sigma Delta Modulator, Kyung Kang

UNLV Theses, Dissertations, Professional Papers, and Capstones

The ever increasing demand for faster and more powerful digital applications requires high speed, high resolution ADCs. Currently, sigma delta modulators ADCs are extensively used in broadband telecommunication systems because they are an effective solution for high data-rate wireless communication systems that require low power consumption, high speed, high resolution, and large signal bandwidths.

Because mixed-signal integrated circuits such as Continuous Time sigma delta modulators contain both analog and digital circuits, mixed signal circuits are not as simple to model and simulate as all discrete or all analog systems. In this dissertation, the delta transform is used to simulate CT …

Songs By Hsiao Tyzen: The Interaction Between His Music And Taiwan, Pei-Ning Ku

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this document is to understand Taiwanese composer Hsiao Tyzen's artistic persona through analysis of the textual and musical characteristics of his songs. This document is comprised of: 1) an historical overview of Taiwan, 2) a history of Taiwanese vocal music, 3) a description of Hsiao Tyzen's life and career, 4) an introduction to Taiwanese diction, 5) an examination and analysis of musical components (melody, rhythm, accompaniment and form) of four of Tyzen's songs, and 6) a conclusion based upon sociological factors, historical influences and musical devices to define what constitutes the stylistic characteristics of the songs of …

Global Climate Change: The Political Impact Of Global Warming On Developing Countries. The Case Studies Of Egypt And Oman, Eugene Thomas O'Neal

UNLV Theses, Dissertations, Professional Papers, and Capstones

The discourse of climate change has become important in the field of political science, as well as in the policy-making community. Climate change has become a political phenomenon that has and will greatly impact political stability regionally and globally. Using the ecological security theory as a framework, I explored the relationship between climate change and political stability in developing countries.

This study utilizes both qualitative and quantitative analyses to investigate the relationship between climate change and its effects on political volatility in developing countries. Using regression models, the author examined all non-OECD countries (140 countries) and their relationship to political …

Subalklaine Volcanism In The Eastern Basin And Range Province: Examples From The Miocene Mccullough Range Volcanic Field And The Pliocene To Holocene Black Rock Desert Volcanic Field, Racheal Leighann Johnsen

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation is composed of three papers that apply geologic mapping, whole rock geochemical and isotopic analysis, and mineral chemistry to describe two large, long-lived (~6 million years), and compositionally heterogeneous volcanic fields and posit sources of the rock types present in each. These fields are the McCullough Range in southern Nevada, which was a locus of volcanic activity from ~19 - 12 Ma and the Black Rock Desert volcanic field in west-central Utah, which began forming at ~6 Ma and is still active today, with the most recent eruption occurring ~720 years ago.

Chapter Two is composed of a …

Thermal Impacts Of Salt On Sandstones And Mudstones In The Lusitanian Basin, Portugal, Brett Perry

UNLV Theses, Dissertations, Professional Papers, and Capstones

In order to assess the impact of salt structures on paleotemperatures in adjacent sedimentary rocks, a field based study which quantified thermally driven diagenetic products as a function of distance from salt was undertaken. Several salt diapirs are now exposed at the surface of the Earth within the Lusitanian Basin and offered a unique opportunity to document paleothermal anomalies by studying thermally controlled diagenesis in adjacent, exposed Upper Jurassic rocks. Four transects were chosen within Upper Jurassic rocks that contained both sandstones and mudstones. Quartz cementation and albitization of feldspars, both of which are thermally driven processes, were quantified in …

New Early Miocene 40ar/39ar Ages For Nakwai, Northwest Kenya, Africa, And Paleontological Analysis Of Meroehyrax Kyongoi Dentition, Dawn Elena Reynoso

UNLV Theses, Dissertations, Professional Papers, and Capstones

Nakwai is a fossiliferous region in the Turkana Basin of northwestern Kenya. Until recently the only ages for the Nakwai formation were based on biostratigraphic correlation with Losodok; a late Oligocene site located to the north of Nakwai. The new 40Ar/39Ar ages in this study range from 23 Ma to 15 Ma and constrain the upper portions of the Nakwai section to the early Miocene. These ages make it the only securely dated fossil locality in the region that represents the earliest Miocene; all of the other early Miocene fossil localities date back to ~20 Ma or younger. The time …

A Survey Of Ekeland's Variational Principle And Related Theorems And Applications, Jessica Robinson

UNLV Theses, Dissertations, Professional Papers, and Capstones

Ekeland's Variational Principle has been a key result used in various areas of analysis such as fixed point analysis, optimization, and optimal control theory. In this paper, the application of Ekeland's Variational Principle to Caristi's Fixed Point Theorem, Clarke's Fixed Point Theorem, and Takahashi's Minimization theorem is the focus. In addition, Ekeland produced a version of the classical Pontryagin Mini- mum Principle where his variational principle can be applied. A further look at this proof and discussion of his approach will be contrasted with the classical method of Pontryagin. With an understanding of how Ekeland's Variational Princple is used in …

Modeling Pavement Distress Rates Within U.S. Air Force Airfields, Lauren Sahagun

UNLV Theses, Dissertations, Professional Papers, and Capstones

Through the review of Pavement Condition Index (PCI) surveys completed at Air Force installations scattered across the continental United States, pavement engineers at the Air Force Civil Engineer Center propose that the predominant factor contributing to pavement distress development is climate. They suggest that within each pavement distress type (i.e. alligator cracking, rutting, spalling, etc.) a geographic pattern exists that is strongly correlated to the conventional climate zones within the US. Knowledge of these geographic patterns would equip pavement engineers and asset managers with a powerful tool to develop purposeful maintenance strategies specific to each distress type.

The following approach …

Designing A Biomimetic Testing Platform For Actuators In A Series-Elastic Co-Contraction System, Ryan Tyler Schroeder

UNLV Theses, Dissertations, Professional Papers, and Capstones

Actuators determine the performance of robotic systems at the most intimate of levels. As a result, much work has been done to assess the performance of different actuator systems. However, biomimetics has not previously been utilized as a pretext for tuning a series elastic actuator system with the purpose of designing an empirical testing platform. Thus, an artificial muscle tendon system has been developed in order to assess the performance of two distinct actuator types: (1) direct current electromagnetic motors and (2) ultrasonic rotary piezoelectric motors. Because the design of the system takes advantage of biomimetic operating principles such as …

Factors Influencing The Perceived Impacts Of Medical Tourism Development On Quality Of Life, Courtney Suess

UNLV Theses, Dissertations, Professional Papers, and Capstones

A structural model is proposed and empirically examined that investigates factors influencing how residents perceive medical tourism's impact on quality of life domains and behavioral responses. A model based on social exchange is adapted as the basis of theory that medical tourism in a destination will affect community conditions and living experiences, which in turn influence residents' support for its development and tax paying behavioral intentions. Analyzed factors influencing how residents perceive medical tourism's affect on community conditions and living experiences underlying quality of life include overall community satisfaction, satisfaction with healthcare, attitudes towards medical tourism and economic performance.

Estimating Aquifer Characteristics And Identification Of A Sub-Basin For Artificial Storage And Recovery, Northeastern Ivanpah Valley, Nevada, Nikolas James Taranik

UNLV Theses, Dissertations, Professional Papers, and Capstones

The identification of a structurally controlled sub-basin with impediments to groundwater flow within Southern Nevada could provide a favorable area for artificial recharge and storage of native or imported water, extending the water supply of Southern Nevada. For this purpose, the area of northeastern Ivanpah Valley was investigated to determine the ability of the aquifer to accept and recover stored water, if acceptable water quality existed in the potential sub-basin storage area, and if structural controls impeded and isolated groundwater flow. The results found evidence the proposed sub-basin is structurally isolated by the McCullough, Roach, and Stateline Faults, which was …

Predicted Performance Of A Skytherm North, A Highly Insulated Building Envelope System And A Frost Protected Shallow Foundation, Kitrina Ann Stratton

UNLV Theses, Dissertations, Professional Papers, and Capstones

How do you design a durable, sustainable, and financeable Net Zero Energy house for a cold weather climate using little or no external energy that is also affordable? Reviewing all of the factors that would influence the design and materials selection of an appropriate response to the issues, the perfect system for housing people, whether it is in response to affordability, durability, comfort, cultural sensitivity, appearance or being locally appropriate, is using some kind of straw bale construction system with an integrated frost protected shallow foundation and a SkyTherm North design.

The focus and intention of this research is to …

Decontamination Protocols For Watercraft And Wildland Firefighting Equipment In Preventing The Spread Of Invasive Quagga (Dreissena Rostriformis Bugensis) And Zebra (Dreissena Polymorpha) Mussels, Ashlie Watters

UNLV Theses, Dissertations, Professional Papers, and Capstones

Quagga and zebra mussels (Dreissena rostriformis bugensis and Dreissena polymorpha) are two invasive species introduced via ballast water discharged by large oceanic cargo ships to the North American Great Lakes in the late 1980s. Once established, the mussels spread quickly. In January 2007, D. rostriformis bugensis was discovered in Lake Mead, NV-AZ, and in that same year, mussels were confirmed further south on the Colorado River in Lakes Mojave and Havasu. Dreissenids clog water intake pipes, water filtration systems, and electric generating plants. The mussels also ruin boat motors, damage recreational equipment, and once established in the reservoir, routine maintenance …

Chinese Outbound Tourists Food Consumption In The U.S.: An Extension Of The Theory Of Planned Behavior, Kaiyang Wu

UNLV Theses, Dissertations, Professional Papers, and Capstones

Although Chinese outbound tourists made enormous economic contribution to the U.S. restaurant industry, they seem to have the tendency to consume Chinese cuisine solely during their international trips. This study applies structural equation modeling (SEM) to evaluate different behavioral beliefs' impact on the intentions of Chinese outbound tourist unfamiliar ethnic food consumption in the U.S. Additionally, this research combines the Theory of Planned Behavior (TPB) and food neophobia, a food-related personality trait to better explain Chinese outbound tourists' food rejection behavior in the U.S.

Results of this study showed safety concern, acceptance of table manners, perceived communication gap and food …

Exact Controllability Of The Lazer-Mckenna Suspension Bridge Equation, Lanxuan Yu

UNLV Theses, Dissertations, Professional Papers, and Capstones

It is well known that suspension bridges may display certain oscillations under external aerodynamic forces. Since the collapse of the Tacoma Narrows suspension bridge in 1940, suspension bridge models have been studied by many researchers. Based upon the fundamental nonlinearity in suspension bridges that the stays connecting the supporting cables and the roadbed resist expansion, but do not resist compression, new models describing oscillations in suspension bridges have been developed by Lazer and McKenna [Lazer and McKenna (1990)]. Except for a paper by Leiva [Leiva (2005)], there have been very few work on controls of the Lazer-McKenna suspension bridge models …

Measuring The Effectiveness Of Race And Sports Book Complimentary Awards Program, Pak Szeto

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this paper is to develop a proper way to measure the effectiveness of complimentary award programs in race and sports books. Like most businesses, casinos seek to increase business volume by offering promotions. According to existing research on casino marketing, promotion activities are often measured by the change in business volume (Lucas & Kilby, 2008). Casino operators should be careful because an increase in business volume does not always equal an increase in profit. To create a positive effect on profit, a promotion must at least create enough gross revenue to offset its cost. Some casino executives …

Nnlo Hard Functions In Massless Qcd, Alessandro Broggio, Andrea Ferroglia, Ben D. Pecjak, Zhibai Zhang

Publications and Research

We derive the hard functions for all 2 → 2 processes in massless QCD up to next-to-next-to-leading order (NNLO) in the strong coupling constant. By employing the known one- and two-loop helicity amplitudes for these processes, we obtain analytic expressions for the ultraviolet and infrared finite, minimally subtracted hard functions, which are matrices in color space. These hard functions will be useful in carrying out higher-order resummations in processes such as dijet and highly energetic top-quark pair production by means of soft-collinear effective theory methods.

On Designing Collaborative Robotic Systems With Real-Time Operating Systems And Wireless Networks, Andrew Jacob Wolin

Boise State University Theses and Dissertations

Robotic devices currently solve many real-world problems but do so primarily on an individual basis. The ability to deploy large quantities of robots to solve problems has not yet been widely embraced partially due to the complex nature of robotics and levels of research investment.

Existing research in robot collaboration largely exists in the forms of models and simulations. This work seeks to accelerate the next level of research in this area by providing a low cost, collaborative capable robotic system. This platform can be used as a gateway to transport simulations into physical representations. This research not only presents …

Finding Success In Elementary Science Across Socioeconomic Boundaries, Jill K. Hettinger

Boise State University Theses and Dissertations

Elementary science education provides a platform for intellectual development, building a foundation of scientific literacy and a first entry point into interest in Science, Technology, Engineering, and Mathematics (STEM) fields. A significant body of research on elementary science education clearly defines what high-quality science education should look like at the elementary level. However, there is little understood about how to implement high-quality science instruction effectively within a school system. Prior research indicates that this problem is further compounded in low socioeconomic elementary schools by a lack of resources, time, and high teacher mobility. I used descriptive research to identify the …

Printing Functional Electronic Circuits And Components, Ahmed Tausif Aijazi

Dissertations

The purpose of this study was to investigate the challenges in printing reliable multilayer flexible circuits, devices and components. Gravure was used as the primary printing process for this work, but due to some limitations of gravure, other printing methods were also investigated. At first a systematic study was done to determine the optimum parameters for the gravure printing of sub 50 micron lines. Commercially available silver nanoparticle inks were printed on a lab scale gravure printer, Accupress®. The highest resolution line that was electrically conductive was 36μm wide. The 9μm, 18μm and 27μm lines were printed but were not …

Place-Based Education: An Impetus For Teacher Efficacy, Tamara Chase Coleman

Dissertations

This research investigated professional development in place-based (PB) methodology on the efficacy of science teachers. While teachers are expected to use best practices they do not always implement them due to a lack of efficacy in implementation. A professional development program (PD) was designed to increase confidence among teachers planning to incorporate PB methods. Place-based education (PBE) is recognized as a best-practice among professional educators. PBE includes the selection, design and engagement with science using the geographic place as the content. The literature reports that student learning and teacher efficacy will improve when teachers are prepared effectively in PB practices. …

Magnetic Nickel Nanoparticles: Synthesis, Environmental Lmplications And Potential Role As Drug Carriers, Setare Tahmasebi Nick

Dissertations

The design and synthesis of well-defined magnetic particles with nanoscale dimensions is opening new avenues in understanding their fundamental chemical and physical properties. Our work describes a novel facile procedure for the synthesis of homogenous isotropic and anisotropic magnetic nickel nanoparticles. These nanoparticles were produced using a wet-chemical process and characterized by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected-area electron diffraction (SAED), powder x-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and thermogravimetric analysis (TGA). Magnetic measurements were acquired using a superconducting quantum interference device (SQUID) magnetometer. While there is significant interest in using magnetic nanoparticles for biological …

Executive Function In Early Childhood: Qualitative And Quantitative Patterns Of Development Among Students Within A Montessori Classroom, Ashley Darcy

Dissertations, Theses and Capstone Projects (Full IR Collection)

This mixed methodology study observed five executive function components (working memory, attention, planning, cognitive flexibility, and inhibitory control) in a Montessori preschool environment for three to five year olds. The purpose of the study was to understand patterns of development for three, four, and five year olds in a natural environment. There were five findings found after analysis: 1) a cluster of components of working memory/planning/attention, 2) patterns of frequency of components, 3) the role of interest in EF components, 4) patterns within each of the five components and 5) patterns of data triangulation between the parent, teacher, and researcher. …

Understanding Student Mathematical Ways Of Knowing: Relationships Among Mathematical Anxiety, Attitude Toward Learning Math, Gender, Ethnicity, And Separate And Connected Ways Of Knowing, Andrea L. Burnes

Dissertations, Theses and Capstone Projects (Full IR Collection)

A quantitative, correlational, survey design with anecdotal qualitative data was used to investigate the relationships among mathematical anxiety, attitude toward learning math, gender, ethnicity, and separate and connected ways of knowing within the context of the mathematics classroom. Participants were 88 student volunteers enrolled in undergraduate mathematics classes at an open admissions technical college in the southeastern United States. Survey data consisted of demographic self-report items, Likert scale items, semantic differential scale items, and one qualitative free-response question. Quantitative data were analyzed by use of either a Spearman Rho, Pearson product moment correlation or an independent samples t-test of significance. …

An Optimal Harvesting Strategy Of A Three Species Syn-Ecosystem With Commensalism And Stochasticity, M. N. Srinivas, A. Sabarmathi, K. S. Reddy, M. A. S. Srinivas

Applications and Applied Mathematics: An International Journal (AAM)

In this paper we have studied the stability of three typical species syn-ecosystem. The system comprises of one commensal S₁ and two hosts S₂ and S₃ . Both S₂ and S₂ benefit S₁ without getting themselves affected either positively or adversely. Further S₂ is a commensal of S₃ and S₃ is a host of both S₁ and S₂. Limited resources have been considered for all the three species in this case. The model equations of the system constitute a set of three first order non-linear ordinary differential equations. …