Physical Sciences and Mathematics Commons^™

Water Source Partitioning For Shrubland Transpiration In A Mixed Phreatophytic Plant Community, Amanda Jean Wagner

UNLV Theses, Dissertations, Professional Papers, and Capstones

Groundwater in the basins of east central Nevada (Great Basin Desert, NV) has been permitted for export to southern Nevada. These basins are also vulnerable to changes in climate that could lead to declining recharge. Any decline in groundwater levels no matter the driving force could significantly impact phreatophytes (deep rooted shrubs), which utilize water from both the vadose zone and the capillary fringe to meet plant water needs, to support growth, and for overall health. A reduction in groundwater due to these forces could have a significant impact on the decoupling of phreatophytes from what is normally a reliable …

The Proof Is In The Pots: Residue Analysis Of Virgin Branch Puebloan Ceramics, Brenna Lynn Wilkerson

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study focuses on better understanding diet and subsistence strategies among Virgin Branch Puebloan groups living in the Moapa Valley in southern Nevada and on the Shivwits Plateau in northwestern Arizona. Gas chromatography-mass spectrometry (GC-MS) was used to identify absorbed food residues in three types of Virgin Branch Puebloan ceramics (Moapa Gray Ware, Shivwits Ware, and Tusayan Virgin Series). The data produced by the residue analysis were used to compare patterns of subsistence between Virgin Branch Puebloan sites in the lowlands along the Muddy River and at upland sites on the Shivwits Plateau as these two areas have different environments …

Biogeochemistry Of A Saline, Alkaline, Terminal Lake Ecosystem In Transition; Walker Lake, Nevada, Katherine Lynn Willever

UNLV Theses, Dissertations, Professional Papers, and Capstones

Walker Lake is a saline, alkaline, terminal lake ecosystem located in west-central Nevada. For over one hundred years, anthropogenic streamflow diversions within the Walker River Basin have ultimately led to little or no water reaching Walker Lake, the basin’s terminus for water flow. These diversions have resulted in a >46 meter decrease in the lake surface altitude and increases in salinity and dissolved salt constituents that have caused the elimination of native fish species. This study examines how the lack of freshwater inflow has altered the physical, chemical, and microbiological structure of Walker Lake during the lake’s ongoing desiccation.

Between …

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 …

A Web Based User Interface For Machine Learning Analysis Of Health And Education Data, Chandani Shrestha

UNLV Theses, Dissertations, Professional Papers, and Capstones

The objective of this thesis is to develop a user friendly web application that will be used to analyse data sets using various machine learning algorithms. The application design follows human computer interaction design guidelines and principles to make a user friendly interface [Shn03]. It uses Linear Regression, Logistic Regression, Backpropagation machine learning algorithms for prediction. This application is built using Java, Play framework, Bootstrap and IntelliJ IDE. Java is used in the backend to create a model that maps the input and output data based on any of the above given learning algorithms while Play Framework and Bootstrap are …

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 …

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 …

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 …

The Hopf Fibration And Encoding Torus Knots In Light Fields, John Vincent Waite

UNLV Theses, Dissertations, Professional Papers, and Capstones

The first sections of this thesis explore a construction of electromagnetic fields first proposed by Bateman and recently rediscovered and expanded upon. With this powerful and elegant tool, I show that it is possible to construct families of EM fields that have a common topological structure that is preserved throughout time. This topological structure, known as the Hopf fibration, has been found to manifest itself in many areas of physics. Due to its utility, I have made a detailed study of it. The final section of this thesis develops an algorithm to parameterize a closed, bounded, and oriented surface that …

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’ …

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 …

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 …

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 …

Mcnp6 Computational-Based Sensitivity Propagation Analysis Of Continuous Neutron Cross-Sections Using The Godiva (Hmf-001) And The Godiver (Hmf-004) Benchmark Criticality Study Cases, Lawrence James Lakeotes

UNLV Theses, Dissertations, Professional Papers, and Capstones

There has been a reduction in funding for theoretical and applied research for improving the nation's database of continuous neutron cross-sections at BNL-NNDC. From 1940 through the late 1980s, research and applied development produced volumes of reliable neutron continuous cross-sections for many isotopes. Currently, the cross-section work has been mainly computational. The focus of this research is mainly centered on the requirements for improving thermal cross-sections to support reactor operations and fuel storage. The research efforts will also helpfully aid in the fast fission spectrum in order to support fast reactor designs for improving safety analysis and feedback coefficients.

This …

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.

(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 …

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 …

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. …

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 …

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 …

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 …

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. …

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, …