Physical Sciences and Mathematics Commons^™

(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 …

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 …

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 …

Empirical Study Of Concurrent Programming Paradigms, Patrick M. Daleiden

UNLV Theses, Dissertations, Professional Papers, and Capstones

Various concurrent programming paradigms have been proposed by language designers in an effort to simplify some of the unique constructs required to handle concurrent programming tasks. Despite these different approaches, however, there has been no general clear winner accepted by software developers and different paradigms are regarded to have strengths and weaknesses in certain areas. This thesis was motivated by the desire to investigate the question of whether or not there are measurable differences between two widely differing paradigms for concurrent programming: Threads vs. Communicating Sequential Processes. The mechanism for observing and comparing these paradigms was a randomized controlled trial …

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. …

A Simulator Application For Distributed Leader Election Algorithms, Sugeeswara Gurudeniya

UNLV Theses, Dissertations, Professional Papers, and Capstones

We present an application program, Distributed Algorithm Simulator, to simulate the execution of distributed leader election algorithms in a ring-network. The application was developed using Visual C# on Microsoft .NET Framework 4.5. The Distributed Algorithm Simulator consists of two major components: A Visual Simulator, which visually demonstrates the execution of the algorithms; and a Textual Simulator, which simulates the execution in text format. In both cases the end-result can be saved to a file.

The Visual Simulator displays the network in a ring orientation with circles representing the nodes, and numbers on them showing the node IDs. The user has …

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 …

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 …

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, …

Impacts To Phytoplankton After The Establishment Of Quagga Mussels In Lake Mead, Nevada, Warren Bruce Turkett

UNLV Theses, Dissertations, Professional Papers, and Capstones

Quagga mussels (Dreissena rostriformis bugensis) are an invasive species that were discovered in Lake Mead in January of 2007, and rapidly spread throughout the lake. Quagga mussels are about the size of a fingernail, but are known to clog pipes, damage infrastructure and alter ecosystems. In large numbers, mussels can have a dramatic impact on an ecosystem by reducing the phytoplankton and potentially increasing toxin producing cyanobacteria. This research analyzed data collected from three separate basins in Lake Mead to determine if water quality characteristics that are commonly impacted by invasive mussels have changed. Transparency, chlorophyll-a, phytoplankton and zooplankton samples …

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 …

A Web-Based Solution For Small Unmanned Aircraft System (Suas) Traffic Management, Monetta Angelique Shaw

UNLV Theses, Dissertations, Professional Papers, and Capstones

There is currently no system in place for safely managing small unmanned aircraft systems (UAS). Small UAS (sUAS) pose a safety hazard to both manned aircraft and people on the ground. The initial solution to this problem proposed in this paper is a system that consists of a web server and an Android mobile application (app). In this solution, the server is only accessible through the Android mobile app. After evaluating the initial solution, we determine that the system in this solution would be unable to quickly adjust to changes in technology and in the sUAS industry. To solve this …

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 …

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.

Neutron-Gamma Discrimination In Elpasolite Scintillator Detector, Brittany Morgan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Existing nuclear stockpiles and weapons-making capabilities imperil the global community. Current nonproliferation efforts involve the research and development of newer, more efficient detection systems that can be deployed for the interdiction and monitoring of special nuclear materials (SNM). Spontaneous and induced fission events in SNM produce neutrons and gamma rays, which can be detected and analyzed, in particular, using scintillator detectors. Various electronic data acquisition systems and data analysis methods have been employed to record and characterize neutron and photon signatures. The goal of this thesis is to develop a new method of discrimination between neutrons and photons in the …

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. …

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 …

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 …

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 …

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 …

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.

Analysis Of Power-Down Systems With Five States, Govind Pathak

UNLV Theses, Dissertations, Professional Papers, and Capstones

We consider a device, which has states ON, OFF and fixed number of intermediate states.In the ON state the device uses full power whereas in the OFF state the device consumes no energy but a constant cost is associated with switching back to ON. Intermediate states use some fraction of energy proportional to the usage time but switching back to the ON state has a constant setup cost depending on the current state. Such systems are widely used to conserve energy, for example to speed scale CPUs, to control data centers, or to manage renewable energy.

We analyze such a …

Mining Unstructured Log Messages For Security Threat Detection, Candace Suh-Lee

UNLV Theses, Dissertations, Professional Papers, and Capstones

As computers become larger, more powerful, and more connected, many challenges arise in implementing and maintaining a secure computing environment. Some of the challenges come from the exponential increase of unstructured messages generated by the computer systems and applications. Although these data contain a wealth of information that is useful for advanced threat detection and prediction for future anomalies, the sheer volume, variety, and complexity of data make it difficult for even well-trained analysts to extract the right information. While conventional SIEM (Security Information and Event Management) tools provide some capability to collect, correlate, and detect certain events from structured …

An Empirical Study On The Impact Of C++ Lambdas And Programmer Experience, Phillip Merlin Uesbeck

UNLV Theses, Dissertations, Professional Papers, and Capstones

Lambda functions have become prevalent in mainstream programming languages, as they are increasingly introduced to widely used object oriented programming languages such as Java and C++. Some in the scientific literature argue that this feature increases programmer productivity, ease of reading, and makes parallel programming easier. Others are less convinced, citing concerns that the use of lambdas makes debugging harder. This thesis describes the design, execution and results of an experiment to test the impact of using lambda functions compared to the iterator design pattern for iteration tasks, as a first step

in evaluating these claims. The approach is a …

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 …

Strategic Molecular Design To Engineer The Electron Affinity Of Self-Assembling Organic Semiconductors, Kelly Nicole Zaugg

UNLV Theses, Dissertations, Professional Papers, and Capstones

Development of electron-accepting (n-type) semiconductors used in organic photovoltaic cells and field effect transistors has been an area of research with less advancement compared to their electron-donating (p-type) counterparts. Currently, the highest performing n-type semiconductor is a fullerene-based derivative (PCBM) with a favorable ELUMO of -4.08 eV. However, PCBM has limited absorption in the visible region and fixed electron affinity. This work focuses on the development of self-assembling n-type materials with controllable electronic properties by strategically lowering ELUMO to a level comparable to PCBM. Molecular design follows an acceptor-acceptor'-acceptor (A-A'-A) configuration; with A being two 2,3-dioctyloxyphenazine substituents connected to A’ …

Innovative Fiber Optic/Thin Film Photovoltaic Systems: Adequately Distributing Daylight While Harvesting Energy, Sean Steven Zurko

UNLV Theses, Dissertations, Professional Papers, and Capstones

On any given year, Las Vegas will be exposed to an average of 85% sunlight during typical daylight hours, while averaging seven peak hours a day. That alone makes Las Vegas a prime candidate for renewable solar energy systems (Solar Direct, 2016). By implementing fiber optics into office buildings in conjunction with thin-film photovoltaics, interior spaces have the potential to be adequately illuminated while simultaneously harvesting electricity. The study will be conducted through analysis and experimental field research with the intent of generating physical data, demonstrating that a hybrid fiber optic - photovoltaic system can at minimum match recommended foot-candle …

High-Pressure Properties Of Several Narrow Bandgap Semiconductors From First-Principles Calculations, Andrew Michael Alvarado

UNLV Theses, Dissertations, Professional Papers, and Capstones

The electronic, thermodynamic, and structural properties of three semiconducting materials, ZnO, InN, and PbS, at high pressure are investigated utilizing first-principles calculations based on density function theory. The first two systems, ZnO and InN, crystalize as hexagonal structures at ambient conditions and transition to a cubic structure at higher pressures. The last system, PbS, is cubic at ambient conditions, but transitions to an orthorhombic structure at higher pressure. At ambient conditions, these materials are well known semiconductors with vast amount of research and a variety of wide ranging applications in electrical devices. However, there is a lack of understanding of …

Systems Of Access: A Multidisciplinary Strategy For Assessing The Social Dimensions Of Sustainability, Christopher Wolsko, Elizabeth Marino, Thomas J. Doherty, Steve Fisher, Amanda S. Green, Briana Goodwin, Ryan Reese, Andrea Wirth

Library Faculty Publications

The concept of access to natural resources has been a specific concern of economists and ecologists and is a distinct component in recent models of social sustainability. Using a series of conceptual and empirical examples, this article extends the notion of access broadly to social institutions and sociocultural norms. We argue that access may be usefully construed as an analytic tool that has direct applicability to many sustainability issues as it allows for cross-disciplinary and public engagement. Here the concept of access, linked to Amartya Sen’s theory of capabilities, also makes visible the multi-scaled and interconnected social processes that influence …