Physical Sciences and Mathematics Commons^™

Supersonic Turbine Cascade Studies Using Computational Fluid Dynamics And Water Table Experiments, Shelby E. Nelson

Honors College Theses

Design engineers use a variety of tools to perform calculations and to aid in the design process. For example, engineers designing gas turbines, specifically the aerodynamicists, use a combination of hand calculations, experimental data, and complex numerical codes to simulate air flow around each blade. Aerodynamicists designing gas turbines must predict the locations of the shocks to locate inefficiencies in the flow. In this thesis, three methods of calculating the shock angles are compared: analytical, experimental, and computational. Three different airfoil shapes are tested: a rectangular flat plate, a supersonic diamond, and a turbine airfoil. Cascade tests of the airfoil …

How Accurately Can The Inclination Angle, Position Angle, And Location Of The Dynamic Center Be Measured From The Neutral Hydrogen Disk In The Central Regions Of Dwarf Galaxies?, John Henry Boisvert

UNLV Theses, Dissertations, Professional Papers, and Capstones

Rotation curves measured using Hi emission are a powerful tool for probing the mass distribution of galaxies. We investigate the accuracy with which rotation curves can be determined using the tilted-ring model. We have examined the effect of varying the dynamic center on measured rotation velocities within the inner regions of galaxies where the disagreement between theory and observation is the greatest. We examine a sample of dwarf galaxies (and one spiral galaxy) from the THINGS high-resolution survey (Walter et al. 2008). We find that the measured rotation curve is quite sensitive to the location of the dynamic center. This …

Simulation And Analysis Of Insider Attacks, Christopher Blake Clark

UNLV Theses, Dissertations, Professional Papers, and Capstones

An insider is an individual (usually an employee, contractor, or business partner) that has been trusted with access to an organization's systems and sensitive data for legitimate purposes. A malicious insider abuses this access in a way that negatively impacts the company, such as exposing, modifying, or defacing software and data.

Many algorithms, strategies, and analyses have been developed with the intent of detecting and/or preventing insider attacks. In an academic setting, these tools and approaches show great promise. To be sure of their effectiveness, however, these analyses need to be tested. While real data is available on insider attacks …

Cretaceous And Eocene U-Pb Zircon Migmatite Ages From The East Humboldt Range Metamorphic Core Complex, Nevada, Jordan Drew

UNLV Theses, Dissertations, Professional Papers, and Capstones

Zircon separates from migmatite samples from the East Humboldt Range (EHR), northern Nevada were U-Pb dated using secondary ionization mass spectrometry. Cathodoluminescence images of zircons show bright anhedral cores with abundant euhedral overgrowths surrounding them.

The overgrowths give U-Pb dates indicating two periods of zircon growth. Inner rims have a Cretaceous age population at 70.6 ± 2.6 Ma. Outer rims give Eocene ages that either fall in to a single-age population at 45 ± 1.3 Ma or are part of a range from 41-31 Ma. Discordant zircon cores have upper intercepts between 1.8 -1.0 Ga.

Cretaceous and Eocene ages are …

Alpcs(2a)-Mediated Photochemical Internalization Of Bleomycin And Concurrent Hyperthermia Of Multicellular Tumor Spheroids, Aaron Andersen

UNLV Theses, Dissertations, Professional Papers, and Capstones

Treatments for glioblastoma multiforme and invasive ductal carcinoma involve surgical resection and adjuvant or concurrent targeted therapies. The goal of the secondary treatment is to reduce the cancer cells in the resection margin and other areas of suspected involvement. Photochemical internalization is a targeted therapy using light to activate photosensitizers embedded in cellular structures to improve the delivery of macromolecules within the cell.

In a previous study, optimized treatment parameters including radiant exposure, and irradiance, concentration of AlPcS(2a), temperature, and the concentration of bleomycin were determined for human ACBT glioma multicell spheroids. The current study investigates the effectiveness of the …

What Can Biochemistry Students Learn About Protein Translation? Using Variation Theory To Explore The Space Of Learning Created By Some Common External Representations, Thomas J. Bussey

UNLV Theses, Dissertations, Professional Papers, and Capstones

Biochemistry education relies heavily on students' ability to visualize abstract cellular and molecular processes, mechanisms, and components. As such, biochemistry educators often turn to external representations to provide tangible, working models from which students' internal representations (mental models) can be constructed, evaluated, and revised. However, prior research has shown that, while potentially beneficial, external representations can also lead to alternative student conceptions.

Considering the breadth of biochemical phenomena, protein translation has been identified as an essential biochemical process and can subsequently be considered a fundamental concept for biochemistry students to learn. External representations of translation range from static diagrams to …

The Distributed Application Debugger, Michael Quinn Jones

UNLV Theses, Dissertations, Professional Papers, and Capstones

Developing parallel programs which run on distributed computer clusters introduces additional challenges to those present in traditional sequential programs. Debugging parallel programs requires not only inspecting the sequential code executing on each node but also tracking the flow of messages being passed between them in order to infer where the source of a bug actually lies.

This thesis focuses on a debugging too called The Distributed Application Debugger which targets a popular distributed C programming library called MPI (Message Passing Interface). The tool is composed of multiple components which run together seamlessly to provide its users an effective way to …

Predicting The Performance Of A Solar Domestic Water Heating System With Evacuated Tube Collectors And Hydronic Radiant Flooring, Kimberly Nicole Hammer

UNLV Theses, Dissertations, Professional Papers, and Capstones

Residential solar thermal system installations have been significantly increasing in the last decade and there exists limited resources for reasonably predicting the performance of those systems. A simulated model is developed in MATLAB® and used to predict the performance of a solar domestic water heating system. In the simulated system, hot water is generated using evacuated tube solar collectors and stored in a domestic hot water storage tank, which utilizes immersed coil heat exchangers. The system is designed to provide hydronic radiant floor heating to its occupants based on the heat loss of a building energy model for an energy-efficient …

Investigating The Feasibility Of Growing Algae For Fuel In Southern Nevada, Faegheh Moazeni

UNLV Theses, Dissertations, Professional Papers, and Capstones

Microalgae capable of growing in waste are adequate to be mass-cultivated for biodiesel, avoiding fertilizers and clean water, two obstacles to sustainability of the feedstock production. This study replaces fertilizers and clean water with waste products. The investigated wastes include (1) the liquid fraction of sewage after solids and particles are removed, known as centrate, and (2) algal biomass residue, i.e. the algae remaining at the end of the lipids extraction process at biofuel plants. These wastes contain sufficient amount of nitrogen and phosphorus required for algal growth. This study proposes a system in which centrate would be used as …

The Evaluation Of Water Storage In Death Valley Using Grace Satellite Data, Maile Sweigart

UNLV Theses, Dissertations, Professional Papers, and Capstones

As drought conditions spread across the United States, concerns over water supplies, water use, and water management policies are growing and possible contributing environmental factors are continually being scrutinized. This thesis examines Death Valley as an analog for Southern Nevada and utilizes NASA EOS data, combined with ancillary climate data, to assess the effect of decadal climate variability on groundwater storage in the Death Valley area. Historical climate data, combined with satellite imagery observations, were compiled and calculated for analyses. Conclusions derived from statistical analyses infer trends between GRACE (Gravity Recovery and Climate Experiment) satellite data and fluctuating levels of …

A Digital Image Processing Method For Detecting Pollution In The Atmosphere From Camera Video, Amrita Nikhil Amritphale

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this thesis we examine the use of digital cameras to detect the magnitude of atmospheric pollution present in the atmosphere. Digital cameras are inexpensive and are being used in countless areas, many of which are outdoors and very public. For example, we see digital cameras located at street intersections, city and state parks, and recreation areas. The theory presented in this paper could help agencies to monitor air quality at any of these sites. Our theory is based on certain molecules and particles that are present in clean air absorb, luminesce, refract, reflect, or scatter the red, green, and …

Investigation Of Peak Load Reduction Strategies In Residential Buildings In Cooling Dominated Climates, Fady Atallah

UNLV Theses, Dissertations, Professional Papers, and Capstones

This investigation of peak load reduction strategies in residential buildings contributes to the global international efforts in reducing energy consumption and is related directly to energy efficiency in residential and commercial buildings. Work reported here involves computer aided building energy simulation of energy efficient and non-energy efficient residential homes coupled with empirical energy consumption data gathered from monitoring an array of energy efficient residential homes. The latter have been implemented for peak load reduction strategies. In addition non-energy efficient residential homes have been monitored to compare performance to the energy efficient homes. This study demonstrates the crucial importance of energy …

Real Time Pattern Recognition In Digital Video With Applications To Safety In Construction Sites, Dinesh Bajracharya

UNLV Theses, Dissertations, Professional Papers, and Capstones

In construction sites, various guidelines are provided for the correct use of safety equipment. Many fatalities and injuries occur to people because of the lack of exercise of these guidelines and proper monitoring of the violations. In order to improve these standards and amend the cause, a video based monitoring tool will be created for a construction site.

Based on the real time video obtained from cameras on the site, a classification algorithm will be created which has the intelligence to recognize if any safety rules have been violated. A classification vector will be created based on the different classifiers, …

An Online Algorithm For The 2-Server Problem On The Line With Improved Competitiveness, Lucas Adam Bang

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this thesis we present a randomized online algorithm for the 2-server problem on the line, named R-LINE (for Randomized Line). This algorithm achieves the lowest competitive ratio of any known randomized algorithm for the 2-server problem on the line.

The competitiveness of R-LINE is less than 1.901. This result provides a significant improvement over the previous known competitiveness of 155/78 (approximately 1.987), by Bartal, Chrobak, and Larmore, which was the first randomized algorithm for the 2-server problem one the line with competitiveness less than 2. Taking inspiration from this algorithm,we improve this result by utilizing ideas from T-theory, game …

Strategic Electronic Property Control Of Self-Assembling Pyrazine-Acenes, Lacie Brownell

UNLV Theses, Dissertations, Professional Papers, and Capstones

Control of electronic properties in organic semiconductor materials is essential for electro-optical applications such as field-effect transistors, light-emitting diodes, and photovoltaic devices. This work is focused on two systems that highlight different approaches for the manipulation of electronic properties: (I) the development of electron-deficient (n-type) materials by selective lowering of E_LUMO and (II) low energy gap materials by controlling both E_LUMO and E_HOMO

To specifically lower E_LUMO, a pyrazine-acene π-platform was extended using electron-withdrawing moieties. These include: pyridine, pyrazine, and benzothiadiazole (system I). From the base pyrazine-acene, the most significant change in E_LUMO of …

Integrating, Developing, And Testing Methods To Generate More Cohesive Approaches To Biogeographic Inference, Mallory Elizabeth Eckstut

UNLV Theses, Dissertations, Professional Papers, and Capstones

As a fundamental component of the developing discipline of conservation biogeography, broadscale analyses of biotic assembly and disassembly across multiple temporal and spatial scales provide an enhanced understanding of how geologic transformations and climate oscillations have shaped extant patterns of biodiversity. As with any scientific field, there are limitations in the case of biogeographic historical reconstructions. Historical reconstructions are only as robust as the theoretical underpinnings of the methods of reconstruction (including data collection, quality, analysis, and interpretation). Nevertheless, historical reconstructions of species distributions can help inform our understanding of how species respond to environmental change.

My dissertation takes a …

Effects Of Environmental Variables On The Reproduction Of Quagga Mussels (Dreissena Rostriformis Bugensis) In Lake Mead, Nv/Az, Richard Steven Ianniello

UNLV Theses, Dissertations, Professional Papers, and Capstones

In 2007, quagga mussels (Dreissena rostriformis bugensis) were found in Lake Mead and have spread downstream on the Colorado River and to other lakes and reservoirs in the Southwestern United States. The quagga mussel's extremely quick colonization of Lake Mead and annual veliger abundance trends provide evidence that the quagga mussels in the Southwest have different reproductive behavior than in previous habitats. This study is one of the first to specifically examine quagga mussel reproduction in the Southwest and examines how quagga mussel reproduction varies at sites known to have different temperatures and other environmental variables resulting from the input …

Development And Validation Of Heat Transfer Model To Predict Indoor Air Temperatures In Roofpond Buildings, Afzal Hossain

UNLV Theses, Dissertations, Professional Papers, and Capstones

Roofponds mimic the ways in which nature tempers and controls the global climate; they utilize higher heat capacity of water to passively control the temperature of the interior space. From a thermal standpoint, roofponds are strong performers, providing high solar savings fractions, interior temperature stability, enhanced thermal comfort and very low operational power requirements. Moreover, due to convective heat transfer within the water bags, heat gains or losses are quickly distributed throughout the roofpond to create a very homogeneous distribution of heat throughout the floor area covered by the system.

Research by Harold Hay and John Yellott (Hay & Yellott, …

A Gaming Application Of The Negative Hypergeometric Distribution, Steven Norman Jones

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Negative Hypergeometric distribution represents waiting times when drawing from a finite sample without replacement. It is analogous to the negative binomial, which models the distribution of waiting times when drawing with replacement. Even though the Negative Hypergeometric has applications it is typically omitted from textbooks on probability and statistics and is not generally known. The main purpose of this thesis is to derive expressions for the mean and variance of a new application of the Negative Hypergeometric to gaming and gambling. Other applications are described as well.

Scheduling Jobs On Two Uniform Parallel Machines To Minimize The Makespan, Sandhya Kodimala

UNLV Theses, Dissertations, Professional Papers, and Capstones

The problem of scheduling n independent jobs on m uniform parallel machines such that the total completion time is minimized is a NP-Hard problem. We propose several heuristic-based online algorithms for machines with different speeds called Q₂||C_max. To show the efficiency of the proposed online algorithms, we compute the optimal solution for Q₂||C_max using pseudo-polynomial algorithms based on dynamic programming method. The pseudo-polynomial algorithm has time complexity O (n T²) and can be run on reasonable time for small number of jobs and small processing times. This optimal offline algorithm is …

Generalizations Of Pascal's Triangle: A Construction Based Approach, Michael Anton Kuhlmann

UNLV Theses, Dissertations, Professional Papers, and Capstones

The study of this paper is based on current generalizations of Pascal's Triangle, both the expansion of the polynomial of one variable and the multivariate case. Our goal is to establish relationships between these generalizations, and to use the properties of the generalizations to create a new type of generalization for the multivariate case that can be represented in the third dimension.

In the first part of this paper we look at Pascal's original Triangle with properties and classical applications. We then look at contemporary extensions of the triangle to coefficient arrays for polynomials of two forms. The first of …

Development And Validation Of The Biophilic Attitudes Inventory (Bai), Lawrence Letourneau

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study investigated the viability of an instrument called the Biophilic Attitudes Inventory (BAI), a pen-and-paper instrument intended to measure attitudes toward nature that, according to naturalist Edward O. Wilson, are rooted in an innate predisposition that humans possess to connect with other forms of life. Utilizing confirmatory factor analysis (CFA), two models were tested (n=334)--a seven-factor model that reflected Stephen Kellert's biophilia typology and a more parsimonious two-factor model. However, neither model proved viable in terms of construct validity. As a result, a new model with four factors was developed via exploratory factor analysis (EFA). A subsequent CFA revealed …

Separation Of Tc From U And Development Of Metallic Tc Waste Forms, Edward Mausolf

UNLV Theses, Dissertations, Professional Papers, and Capstones

The isotope Technetium-99 (⁹⁹Tc) is a major fission product of the nuclear industry. In the last decade, approximately 20 tons of 99Tc have been produced by the US nuclear industry. Due to its long half-life (t_1/2 = 214,000 yr), beta radiotoxicity, and high mobility as pertechnetate [TcO₄]^-, Tc represents long-term concern to the biosphere. Various options have been considered to manage ⁹⁹Tc. One of them is its separation from spent fuel, conversion to the metal and incorporation into a metallic waste form for long-term disposal. After dissolution of spent fuel in nitric …

Understanding Effects Of Changes In Land Use, Environmental Parameters, Habitat Characteristics On The Great Basin Aquatic Invertebrates Using Ecological Stoichiometric Theory, Knut Mehler

UNLV Theses, Dissertations, Professional Papers, and Capstones

Many freshwater ecosystems in the Great Basin have undergone dramatic alteration over the past decades due to groundwater withdrawal, water diversion and changes in land use. These changes have affected benthic food web dynamics by altering the availability of chemical key elements for primary and secondary producers, by loss of biodiversity and extinction of endemic species. However, only few studies are available that addresses the link between changes in land use, habitat characteristics and its effects on benthic macroinvertebrates (BMI) communities comprehensively and little attention has been given to integrating physiochemical aspects to link ecosystem functions.

This dissertation analyzes the …

Communication Artifacts And Interaction Evaluation For Requirements Engineering, Miloslava Plachkinova

UNLV Theses, Dissertations, Professional Papers, and Capstones

This paper aims to answer an important question regarding the development of new information systems (IS): "What is the predominant factor for the selection of communication artifacts for requirements engineering (RE)?". Many researchers have focused on the RE and communication as separate disciplines, but little or no research addressed the RE communication issues. These problems are important because they often lead to misunderstanding and misinterpretation of the gathered requirements. We develop expectations about the RE communication process based on prior literature from both disciplines and we test them through several case studies. Our methodology consists of analysis of six case …

Initial Elastic Modulus Degradation Using Pressuremeter And Standard Penetration Test Results At Two Sites, Dustin Robbins

UNLV Theses, Dissertations, Professional Papers, and Capstones

In-situ testing was performed at two sites consisting of pre-bored pressuremeter testing, seismic surface wave testing to develop a shear wave velocity profile, and Standard Penetration testing during the soil boring phase in order to evaluate the feasibility of using large shallow foundations for a project. This study focuses on a comparison of the in-situ direct measurements of soil stiffness obtained from this testing program. The small strain modulus obtained from the seismic surface wave test results is compared to the intermediate strain modulus obtained from both the initial loading pressuremeter modulus and reload pressuremeter modulus. The modulus calculated from …

Forensic Signatures Of Chemical Process History In Uranium Oxides, Jonathan Plaue

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation comprehensively explores and develops new tools for nuclear forensic science to facilitate the identification of chemical process history in uranium oxides. Nuclear forensics is an emerging discipline motivated by the need to prevent and combat malevolent acts involving nuclear and radiological materials. This dissertation examined process signatures in uranium oxide powders, precursors, and sintered fuel pellets.

Signatures were investigated on set of powder and pellet exemplars synthesized in the laboratory and a set of real‐world samples with process information obtained from the literature or manufacturer. The examined techniques included morphology as revealed by scanning electron microscopy, near‐infrared reflectance …

Real Time Digital Night Vision Using Nonlinear Contrast Enhancement, Nishikar Sapkota

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis describes a nonlinear contrast enhancement technique to implement night vision in digital video. It is based on the global histogram equalization algorithm. First, the effectiveness of global histogram equalization is examined for images taken in low illumination environments in terms of Peak signal to noise ratio (PSNR) and visual inspection of images. Our analysis establishes the existence of an optimum intensity for which histogram equalization yields the best results in terms of output image quality in the context of night vision. Based on this observation, an incremental approach to histogram equalization is developed which gives better results than …

Soil Moisture Recognition And The Spatial Distribution Of Storm Activity In The Mojave Desert Using High-Resolution Aster And Modis Imagery For Thermophysical Mapping, Russell J. Skuse

UNLV Theses, Dissertations, Professional Papers, and Capstones

Climate models suggest that the Mojave Desert ecoregion is vulnerable to becoming drier in the future, and as the human population grows and development increases, environmental stresses will likely increase. Determining the spatial distribution and variation of soil moisture on a regional scale is an essential component to climate change, hydrologic, and habitat analyses. Soil permeability and sediment stability are characteristics that have been shown to be measurable from remote sensing observations. The primary objective of this project is to map the mechanical composition of the surface materials in the Mojave Desert ecoregion with implications for soil permeability, sediment stability, …

Dispersal Ecology Of Desert Mosses Along Gradients Of Elevation, Wildfire Disturbance And Local Niche, Robert Joseph Smith

UNLV Theses, Dissertations, Professional Papers, and Capstones

Much of the variation in plant communities can be explained by the dispersal of individuals across landscapes, an ecological process that contributes to clinal variation, post-disturbance recovery and habitat occupancy. The role of dispersal is of particular concern for Mojave Desert plant communities that may not be able to tolerate recent departures from historical fire regimes. The aim of this thesis was to infer how dispersal is reflected by patterns of diversity in disturbed and undisturbed bryophyte communities in the Spring Mountains of southern Nevada. Chapter 2 presents an examination of sub-surface bryophyte communities (propagule "soil-banks") along a 1400 m …