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Ab Initio Structure Determination And Property Characterization Of High-Pressure Ca-O Compounds And Li2(Oh)Br Crystals, Christopher Higgins

UNLV Theses, Dissertations, Professional Papers, and Capstones

Theoretical modeling and computational simulations play an important role in materials research. In this thesis, we report on the study of two material systems using various computational methods. The first material system studied here are Cax-Oy compounds under high pressure. Calcium and oxygen are amongst the most abundant elements on Earth, and they form the compound calcium oxide (CaO) that is widely used and very stable at ambient pressures. Although the crystal structure and chemical composition of CaO seems to be simple and well understood, metastable or stable Ca-O compounds with unconventional stoichiometry may exist at high pressures. In this …

Impedance Spectroscopy Studies Of Yttria Stabilized Zirconia Under Extreme Conditions, Quinlan Blaine Smith

UNLV Theses, Dissertations, Professional Papers, and Capstones

Yttria Stabilized Zirconia (YSZ) is of interest for many industries. Varying amounts of Yttria (Y2O3) can be doped into Zirconia (ZrO2) to create materials with specific characteristics. For instance, 3mol% YSZ (3YSZ) is known to be a super hard material and is used as a coating on drill tips and as an abrasive. Eight mol% YSZ (8YSZ) is commonly used as a solid electrolyte in Solid Oxide Fuel Cells because of its good ionic conducting abilities and stability at high temperatures. In this thesis project, a novel experimental setup was created and used to study the ionic conductivity of (3 …

Is Being Green, White? A Critical Ethnographic Study Of Social Norms In Conservation, Heather Whitesides

UNLV Theses, Dissertations, Professional Papers, and Capstones

Attempts to measure and implement conservation norms have consistently upheld and promoted the dominant culture’s practices and beliefs. This has led to oppression of non-dominant populations, thereby hindering these populations’ access to various opportunities to participate in conservation based activities. This has historically, and still today, led to the segregation of non-dominant populations from environmental participation and has misrepresented their beliefs and actions relative to definitions of conservation citizenship and in the broader literature on conservation, conservation measurements, outdoor recreation, and pro-environmental behavior.

This research sought to extend the existing literature on conservation, specifically on the measurements of recreation practices …

The Revolution Will Be Computed: Fantasy, Apple Computer, And The Ethos Of Silicon Valley, Misti Yang

UNLV Theses, Dissertations, Professional Papers, and Capstones

My thesis undertakes a rhetorical analysis of the discourse surrounding the development of the personal computer and Apple Computer as a case study in Silicon Valley discourse. The analysis spans twenty years (1964-1984) starting with San Francisco-area computer hobbyist clubs and ending with the release of Macintosh by Apple Computer. Symbolic convergence theory (SCT) and fantasy theme analysis (FTA) provide the primary methodology for my work. Because SCT/FTA developed from small group communication research, they are fitting tools for understanding how small groups of people impassioned about building something new can impact public discourse. I connect SCT/FTA with a materialist …

Characterizing The Earliest Stages Of Partial Melting: A Study Of The Pyrometamorphic Aureole Of Miocene Mt. Perkins Pluton, Northwest Arizona, Mathew Beshears

UNLV Theses, Dissertations, Professional Papers, and Capstones

Partial melting is an important process in the evolution of continental crust. Due to its progressive nature, evidence of the early stages of partial melting is often overprinted by later, advanced stages of partial melting. Experimental work has provided a model for the early stages of partial melting, but is limited to timescales of hours to weeks. Pyrometamorphic environments within the contact aureole of mafic intrusions provide natural laboratories for the study of the earliest stages of partial melt production on geologic time scales of 102 collected along two traverses of the tilted pyrometamorphic aureole of the Mt. Perkins pluton …

On The Scattering Of An Acoustic Plane Wave By A Soft Prolate Spheroid, Joseph Michael Borromeo

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis solves the scattering problem in which an acoustic plane wave of propagation number K1 is scattered by a soft prolate spheroid. The interior field of the scatterer is characterized by a propagation number K2, while the field radiated by the scatterer is characterized by the propagation number K3. The three fields and their normal derivatives satisfy boundary conditions at the surface of the scatterer. These boundary conditions involve six complex parameters depending on the propagation numbers. The scattered wave also satisfies the Sommerfeld radiation condition at infinity. Through analytical methods, series representations are constructed for the interior field …

A Case For Chiral Contributions To Nondipole Effects In Photoionization Using Linearly Polarized Soft X-Rays, Kyle Patrick Bowen

UNLV Theses, Dissertations, Professional Papers, and Capstones

Modelling angular distributions of photoelectrons requires making accurate approximations of both the incoming light and the behavior of bound electrons. The experimental determination of photoelectron angular distributions is crucial to the development of accurate theoretical models governing the light-matter interaction. To date, many models have relied upon the dipole approximation, which assumes a constant electric field as the source of ionization. Despite knowing that the dipole approximation would break down as photon energy increased, the precise limit was unclear. Over the past two decades, a strong case has been made that corrections to the dipole approximation are necessary for accurately …

Water Harvesting Methods And The Built Environment: The Role Of Architecture In Providing Water Security, Adam Joseph Bradshaw

UNLV Theses, Dissertations, Professional Papers, and Capstones

Two prototype thermoelectric atmospheric water generator (AWG) devices were constructed and evaluated for their performance in collecting water. The devices consisted of two Peltier thermoelectric cooling (TEC) modules connected to a heat sink and a condensing surface. The TEC/heat sink assembly was anchored to an air-well constructed of extruded polystyrene and 3D-printed frames, and a fan was installed to draw in surrounding air. The condensing surfaces were either copper or aluminum and featured a surface area larger than the cold side of the TEC.

The performance of aluminum and copper surfaces were compared by measuring condensate collected after a test …

The Experience Of Teaching Online Secondary Science, Cynthia Ann Clark

UNLV Theses, Dissertations, Professional Papers, and Capstones

The experience of teaching online secondary science was investigated through the lens of developmental phenomenography. Recorded phenomenographic interviews were conducted with thirteen secondary science teachers who were teaching online in two countries and four states. After analyzing the transcripts individually and as a whole, seven themes were identified: (1) Virtual Labs and Learning, (2) Student Learning and Factors Involved, (3) Communication and Instruction, (4) Teaching as Collaboration/Social Aspect, (5) Teaching and Learning as Assessment, (6) Curriculum Effects on Teaching and Learning, and (7) Online Structure Effects on Teaching and Learning. The structures of awareness of these seven themes formed the …

Identify An Ideal Residential Wall Assembly For Las Vegas Climate Considering Construction Cost, Energy Performance And Embodied Energy, Johny Corona

UNLV Theses, Dissertations, Professional Papers, and Capstones

Global warming and climate change has drawn great concerns in recent years due to the impact residential buildings have on the environment. Heating and cooling consumption make up most of household energy in the desert southwest. This energy demand is a big contributor of carbon emissions being release on to the environment. In an effort to minimize energy consumption, this research study aims to identify an energy efficient wall assembly that can be use in the U.S. desert southwest, that is suitable for the environment. With the use of research and simulations, using BEopt version 2.4.0.1, this investigation compares and …

Direct Dissolution And Electrochemical Investigation Of Cerium And Uranium In Ionic Liquid, Janelle Droessler

UNLV Theses, Dissertations, Professional Papers, and Capstones

The solubility, coordination and speciation of f-elements in ionic liquids (ILs) has been the focus of numerous studies because the purely ionic systems have unique physical properties that can be exploited in comparison to aqueous, organic, or molten salt systems. Ionic liquids are thermally stable, have negligible vapor pressure, and are electrochemically stable at negative potentials that encompass the reduction potential of actinide species. Literature has suggested that the properties of ILs could potentially be utilized in the nuclear fuel cycle for separations and reprocessing. However, the solubility of f-elements in ILs has been significantly lower compared to traditional solvents. …

(U-Th)/He Studies Of The Southern Snake Range Metamorphic Core Complex, Nv And Gypsum Valley Salt Wall, Paradox Basin, Co, Usa, Sarah Lynn Evans

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation presents three studies that investigate extension in the Southern Snake Range (SSR) metamorphic core complex (MCC) of east-central Nevada and a thermal anomaly associated with the Gypsum Valley salt wall (GVSW) of southwestern Colorado. Low temperature thermochronologic studies using the (U-Th)/He system have been applied in numerous geologic settings to understand erosional and tectonic denudation processes. Two of the studies presented use (U-Th)/He thermochronology, combined with other techniques, to investigate the extensional history of the SSR and the extent of the GVSW thermal anomaly. Both of these studies present novel methods for understanding the thermal histories of the …

Security Threats From Uas And Its Mitigation Through Detection And Tracking, Sai Ram Ganti

UNLV Theses, Dissertations, Professional Papers, and Capstones

Unmanned Aerial Systems (UAS) are being used commonly for surveillance, providing valuable video data and reducing risk for humans wherever applicable. The cost of small UAS can range from as low as $30 to high as $5000, which makes it affordable by everyone. Most of the UAS are equipped with a camera which results in activities like disruption of privacy or capturing sensitive data. This research is aimed at developing a system which can detect and identify a drone and apply some counter measures to stop its functions or make it go away. The air traffic will increase significantly in …

Differences In Perceived Importance Of Preventative Services And Healthcare Provider Trust Among Hispanics, Jonathan James Gore

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Hispanic population varies greatly in their risk factors, health outcomes and access to care by country of origin, level of education and language dominance (Vega & Amaro, 1994) (Fiscella, Franks, Doescher, & Saver, 2002b). The differences within the Hispanic population also extend to their knowledge and attitudes toward health choices and maintenance, where they receive their health information, and what they access to meet their health care needs. Subpopulations within the Hispanic community as defined by language dominance and nativity must be understood as separate and distinct so that the health needs of each can be adequately addressed. The …

Top-K Nodes Identification In Big Networks Based On Topology And Activity Analysis, Sweta Gurung

UNLV Theses, Dissertations, Professional Papers, and Capstones

Graphs and Networks have been the most researched topics with applications ranging from theoretical to practical fields, such as social media, genetics, and education. In many competitive environments, the most productive activities may be interacting with high-profile people, reading a much-cited article, or researching a wide range of fields such as the study on highly connected proteins. This thesis proposes two methods to deal with top-K nodes identification: centrality-based and activity-based methods for identifying top-K nodes. The first method is based on the topological structure of the network and uses the centrality measure called Katz Centrality; a path based ranking …

Comparing The Effects Of Two Utility Value Interventions On Graduate Students' Interest, Performance, And Perceptions Of Utility Value, Ivan Vladimirov Ivanov

UNLV Theses, Dissertations, Professional Papers, and Capstones

The present study compares the immediate and delayed effects of teacher- vs. student-generated utility value interventions on students' interest, performance, and perceptions of utility value. In addition, it examines whether sense of autonomy mediates the relationship between type of utility value intervention and performance. The study is grounded in self-determination theory and expectancy-value theory and adopts a 3x3 mixed model design, with random assignment of participants to two relevance instruction conditions and a control condition.

Findings suggest that the teacher-generated utility value intervention was more effective than the student-generated utility value intervention and the control condition in terms of increased …

Effects Of Hydraulic Connections On Unsaturated Flow In Dual-Permeability Media, Jeevan Jayakody

UNLV Theses, Dissertations, Professional Papers, and Capstones

A geological medium that exhibits two distinct types of flow is known as dual-permeability medium. Unconsolidated deposits composed of coarse (> 2 mm diameter) clasts (gravel, talus, rockslide debris), engineered systems (heap leach piles, capillary barriers, rock fill), and mine/construction waste fall into this category. The large inter-clast pores that are characteristic of this type of media will drain at near zero matric potentials constraining flow to the interiors of porous clasts and/or the clast surfaces. In either case, water must pass through hydraulic bridges (porous contacts and/or pendular water) that form physical connections between neighboring clasts. Therefore, properties of …

A Study On Automated Process For Extracting White Blood Cellular Data From Microscopic Digital Injured Skeletal Muscle Images, Bibek Karki

UNLV Theses, Dissertations, Professional Papers, and Capstones

Skeletal muscle injury is one of the common injuries caused by high-intensity sports activities, military related works, and natural disasters. In order to discover better therapies, it is important to study muscle regeneration process. Muscle regeneration process tracking is the act of monitoring injured tissue section over time, noting white blood cell behavior and cell-fiber relations. A large number of microscopic images are taken for tracking muscle regeneration process over multiple time instances. Currently, manual approach is widely used to analyze a microscopic image of muscle cross section, which is time consuming, tedious and buggy.

Automation of this research methodology …

Inner Experience And Self-Ratings Of Inner Speaking, Jason Michael Kelsey

UNLV Theses, Dissertations, Professional Papers, and Capstones

Questionnaires are often used as measures of inner experience. This study questions the adequacy of such measures, using inner speech as an example. We compared two questionnaire measures of inner speaking to each other and to inner experience as apprehended by Descriptive Experience Sampling (DES, a naturalistic, high fidelity method of exploring inner experience). Undergraduate volunteers (N = 260) took two questionnaires designed to measure inner speaking: the Self-Talk Scale (STS) and the Nevada Inner Experience Questionnaire (NIEQ). A subset of these (N = 16) participated in DES to investigate their inner speaking with fidelity. Scores on the NIEQ and …

Water Balance And Moisture Dynamics Of An Arid And Semi-Arid Soil: A Weighing Lysimeter And Field Study, Jeremy E. Koonce

UNLV Theses, Dissertations, Professional Papers, and Capstones

Semi-arid and arid environments are characterized by low precipitation and high evapotranspiration (ET), leaving little water available for discharge into surface water bodies and groundwater recharge. For these water-limited environments, understanding the relationships between precipitation, ET, and soil moisture is critical. These relationships not only affect water resources in these increasingly populated regions but are also necessary to predict the impact of climate change on semi-arid and arid ecosystems.

The overall goal of this dissertation was to shed light on the quantitative relationships between precipitation, evaporation, ET and soil moisture dynamics in an arid and a semi-arid environment. A three-step …

Algorithms For Monotone Paths With Visibility Properties, Bikash Lama Bamjan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Constructing collision-free paths in Euclidean space is a well-known problem in computational geometry having applications in many fields that include robotics, VLSI, and covert surveillance. In this thesis, we investigate the development of efficient algorithms for constructing a collision-free path that satisfies directional and visibility constraints. We present algorithms for constructing monotone collision-free paths that tend to maximize the visibility of the boundary of obstacles. We also present implementation of some monotone path planning algorithms in Java Programming Language.

A Case Study: Students' Mathematics-Related Beliefs From Integrated Stem Model-Eliciting Activities, Cathrine Maiorca

UNLV Theses, Dissertations, Professional Papers, and Capstones

This case study examines the mathematics-related beliefs of fourth and fifth grade students who participated in an after-school integrated science, technology, engineering and mathematics (STEM) program where participants completed four Model-Eliciting Activities. The research questions addressed by this study are, What is the nature of the change in mathematics-related beliefs of students who participate in an after-school MEA program? In particular, what is the difference, if any, of the nature of the change in beliefs across varying ability levels? The framework used to describe these beliefs was developed by Kloosterman and includes beliefs about the nature of mathematics and mathematics …

Efficient Algorithms For Clustering Polygonal Obstacles, Sabbir Kumar Manandhar

UNLV Theses, Dissertations, Professional Papers, and Capstones

Clustering a set of points in Euclidean space is a well-known problem having applications in pattern recognition, document image analysis, big-data analytics, and robotics. While there are a lot of research publications for clustering point objects, only a few articles have been reported for clustering a given distribution of obstacles. In this thesis we examine the development of efficient algorithms for clustering a given set of convex obstacles in the 2D plane. One of the methods presented in this work uses a Voronoi diagram to extract obstacle clusters. We also consider the implementation issues of point/obstacle clustering algorithms.

Creating A Dynamic, Multi-Purpose Correction For Multiple Geometries And Field Sizes To Account For Off-Axis And Asymmetric Backscatter With Varian Portal Dosimetry, Remy Manigold

UNLV Theses, Dissertations, Professional Papers, and Capstones

Intensity modulated radiation therapy and volumetric modulated arc therapy are increasingly common in radiation therapy due to their benefits of target conformity and normal tissue sparing. Due to the complexities of plan delivery and the precision required, the dose delivered must be accurately measured for quality assurance (QA). One of the most efficient ways to perform patient-specific QA when using clinical linear accelerators (linac) is to use an electronic portal imaging device (EPID). Amorphous silicon (aSi) Electronic Portal Imaging Devices (EPIDs) are attached to the linac and can provide real-time feedback with spatial resolution on the order of sub-millimeter pixel …

Development Of Solar Experiments With Remote Laboratory Capability For Engineering Education Of The Future, Otto Kyle Neidert

UNLV Theses, Dissertations, Professional Papers, and Capstones

Educating future engineers will be handled differently as this modern society has various methods of doing so and a plethora of knowledge to pursue. The availability of computers and internet has changed many things. A subject that is relevant in today’s world but not common to most people and some engineers is solar energy. As part of a grant from the National Science Foundation that was awarded to Louisiana State University (LSU), Florida State University (FSU), and the University of Nevada, Las Vegas (UNLV), the UNLV Center for Energy Research partnered with them to create solar application based learning modules. …

Tearing Up The Tallgrass, Brett Salsbury

UNLV Theses, Dissertations, Professional Papers, and Capstones

This creative thesis project is a culmination of the Master of Fine Arts in Creative Writing degree at UNLV. The thesis—currently titled Tearing up the Tallgrass—was composed entirely during my graduate semesters at UNLV. As a book of poetry, it explores the dynamics of humans in nature, white privilege, objectivity, fact- and myth-making, and artistic practice. Written under the supervision of Claudia Keelan (committee chair) and Donald Revell (committee member), my committee further includes P. Jane Hafen (English) and Pierre Lienard (Anthropology). Their disparate subject and genre interests are meant to diversify the feedback received during this project’s composition. Some …

Changes In Teachers' Constructivist Beliefs And Practices From Preservice To Inservice Teaching: A Mixed Methods Approach, Christina Joan Santoyo

UNLV Theses, Dissertations, Professional Papers, and Capstones

Teacher candidates’ development into novice teachers is a social process that depends on their teaching context as well as the mentors who help them through the process. Viewed through the lens of social identity development theory and mentoring theory, this study used an embedded, mixed methods design to understand how and to what extent six Alternative Route to Licensure teacher candidates’ beliefs and practices differed from preservice to inservice teaching. Mixed-methods data were collected using observation, semi-structured interviews, and partial interval recording. The six participants included secondary math, English, science, and social studies preservice-turned-novice teachers. In order to understand the …

Parallel Static Object Detection, Tirambad Shiwakoti

UNLV Theses, Dissertations, Professional Papers, and Capstones

The need for parallelism is growing with the broadening of computing in the real world where computing is an integral part of any field. In the early days of computing, adding transistors to the CPU could solve computation complexity. This is not the case now, where we can no longer advance the hardware capabilities at the pace of the advancement of computing problems. One of the fields which is intensive in computation is image processing. If it were just for one frame of an image, we could cope with the computation overhead. When the need is to compute video frames, …

Interrelationships Among Teacher Self-Efficacy, Collective Teacher Efficacy, And Teachers’ Pedagogical Content Knowledge, Qingmin Shi

UNLV Theses, Dissertations, Professional Papers, and Capstones

A teacher’s self and collective efficacies are assumed to be related to his or her teaching and student learning in a specific content area. His or her pedagogical content knowledge in the subject content area is also assumed to shape his or her teaching practice. In addition, the quality of one’s teaching is influenced by the context in which teaching is situated. However, the relationships among teacher self-efficacy, collective teacher efficacy, and pedagogical content knowledge situated in individualist and collectivist contexts of teaching mathematics have not been empirically examined adequately. Through the lens of social cognitive theory on teacher efficacy, …

Causes Of Change Orders And Its Impact On Road Maintenance Contracts, Kabindra Kumar Shrestha

UNLV Theses, Dissertations, Professional Papers, and Capstones

Change orders (CO) commonly generate cost-growth, schedule-growth or both, in construction as well as in maintenance contracts. Literature reviews revealed that the causes and impact of CO on new construction contracts had been comprehensively studied, but the causes and impact of CO in maintenance contracts remained neglected. This study collected CO data on road maintenance contracts to determine the amount of CO and the most frequent and high-risk road maintenance activities that had CO. A Delphi study was conducted with 33 maintenance engineers from the state Department of Transportation (DOT) to identify causes of CO and its impact on cost …