Digital Commons Network^™

Simultaneous Determination Of Multiple Actinide Elements In A Variety Of Soils Utilizing A Standardized Sequential Extraction Protocol, Sherry Alina Faye

UNLV Theses, Dissertations, Professional Papers, and Capstones

To obtain a better understanding of the mobility of actinide element contaminants in the environment, the association of the contaminants with specific host phases of soils and sediments must be investigated. This investigation is most commonly conducted using sequential extraction techniques that employ the selective dissolution of soil phases with increasingly aggressive chemical treatment. Though several sequential extraction studies exist in literature, conclusions cannot be made by direct comparison of data due to the lack of uniformity in the protocols used. This work aims to continue development of a standard sequential extraction protocol and expanding its capabilities to include the …

Novel Deployment Of Elpasolites As A Dual Neutron / Gamma-Ray Directional Detector, Amber Lynn Guckes

UNLV Theses, Dissertations, Professional Papers, and Capstones

At a time when upholding national security has never been more important, there exists a need for the advancement of radiation detection technologies. Neutron and photon detectors are essential to fulfilling mission areas including detection and localization of missing, stolen or smuggled radiological or nuclear materials, quantification of the effects of a radiological or nuclear event, and supporting nonproliferation efforts. The aim of this study was to evaluate a new radiation detector based on the scintillation elpasolite compound Cs2LiYCl6:Ce (CLYC) for simultaneous measurements of neutron and photon flux and the localization of radiation sources. Previous studies performed on the CLYC …

Technetium Sulfide: Fundamental Chemistry For Waste Storage Form's Application, Maryline Ghislaine Ferrier

UNLV Theses, Dissertations, Professional Papers, and Capstones

Technetium is the lightest radioelement. The isotope ⁹⁹Tc has around a 6% yield from ²³⁵U with a half-life of 2.13 x 10⁵ years. The high mobility of TcO₄^-, the common chemical form of technetium in the environment makes ⁹⁹Tc an isotope of concern in nuclear waste management. Despite its important role in radiopharmaceuticals and in the nuclear fuel cycle, the fundamental chemistry of technetium is not as well developed as that of the neighboring transition metals; one of the most striking examples being its sulfide chemistry.

Only two technetium binary sulfide compounds had …

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

UNLV Theses, Dissertations, Professional Papers, and Capstones

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

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

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

UNLV Theses, Dissertations, Professional Papers, and Capstones

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

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

UNLV Theses, Dissertations, Professional Papers, and Capstones

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

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

Modeling And Analysis Of Pedestrian Flows, Romesh Khaddar

UNLV Theses, Dissertations, Professional Papers, and Capstones

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

A lot of researches on pedestrian flows have …

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

UNLV Theses, Dissertations, Professional Papers, and Capstones

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

Concurrent Localized Wait-Free Operations On A Red Black Tree, Vitaliy Kubushyn

UNLV Theses, Dissertations, Professional Papers, and Capstones

A red-black tree is a type of self-balancing binary search tree. Some wait-free algorithms have been proposed for concurrently accessing and modifying a red-black tree from multiple threads in shared memory systems. Most algorithms presented utilize the concept of a "window", and are entirely top-down implementations. Top-down algorithms like these have to operate on large portions of the tree, and operations on nodes that would otherwise not overlap at all still have to compete with and help one another.

A wait-free framework is proposed for obtaining ownership of small portions of the tree at a time in a bottom-up manner. …

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

UNLV Theses, Dissertations, Professional Papers, and Capstones

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

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

UNLV Theses, Dissertations, Professional Papers, and Capstones

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

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

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

UNLV Theses, Dissertations, Professional Papers, and Capstones

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

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

UNLV Theses, Dissertations, Professional Papers, and Capstones

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

Chapter Two is composed of a …

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

UNLV Theses, Dissertations, Professional Papers, and Capstones

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

Identification Of Long Term Changes And Evaluation Of The Relationships Among Streamflow Variability And Oceanic-Atmospheric Indices, Soumya Sagarika

UNLV Theses, Dissertations, Professional Papers, and Capstones

To examine the effects of climate variability on streamflow, this thesis presents a comprehensive analysis of the streamflow variability of the continental United States and its association with oceanic-atmospheric indices. First, the presence of trends with consideration of short term and long term persistence followed by shifts over the past years in the continental U.S. streamflow were analyzed by using the non-parametric tests: Mann Kendall and Pettitt. Second, the spatio-temporal relationships between seasonal streamflow variability of continental U.S. and sea surface temperatures (SST) and 500 mbar geopotential height (Z500) of the Pacific and Atlantic were established using the singular valued …

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

UNLV Theses, Dissertations, Professional Papers, and Capstones

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

The following approach …

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

UNLV Theses, Dissertations, Professional Papers, and Capstones

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

Empirical Studies On Interest Rate Derivatives, Xudong Sun

UNLV Theses, Dissertations, Professional Papers, and Capstones

Interest rate models are the building blocks of financial market and the interest rate derivatives market is the largest derivatives market in the world. In this dissertation, we shall focus on numerical pricing of interest rate derivatives, estimating model parameters by Kalman filter, and studying various models empirically. We shall propose a front-fixing finite element method to price the American put option under the quadratic term structure framework and compare it with a trinomial tree method and common finite element method. Numerical test results show the superiority of our front-fixing finite element method in the aspects of computing the option …

A Study Of Graphical Permutations, Jessica Thune

UNLV Theses, Dissertations, Professional Papers, and Capstones

A permutation π on a set of positive integers {a_1,a_2,...,a_n} is said to be graphical if there exists a graph containing exactly a_i vertices of degree (a_i) for each i. It has been shown that for positive integers with a_1

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

UNLV Theses, Dissertations, Professional Papers, and Capstones

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

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

UNLV Theses, Dissertations, Professional Papers, and Capstones

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

The focus and intention of this research is to …

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

UNLV Theses, Dissertations, Professional Papers, and Capstones

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

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

UNLV Theses, Dissertations, Professional Papers, and Capstones

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

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

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

UNLV Theses, Dissertations, Professional Papers, and Capstones

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

A Quasi-Classical Logic For Classical Mathematics, Henry Nikogosyan

Honors College Theses

Classical mathematics is a form of mathematics that has a large range of application; however, its application has boundaries. In this paper, I show that Sperber and Wilson’s concept of relevance can demarcate classical mathematics’ range of applicability by demarcating classical logic’s range of applicability. Furthermore, I introduce how to systematize Sperber and Wilson’s concept of relevance into a quasi-classical logic that can explain classical logic’s and classical mathematics’ range of applicability.

Modeling Hedonic Processing And Anhedonia In Depression, Kevin Mercado

Honors College Theses

Depression is characterized by low positive emotion and a lack of pleasurable experiences, or anhedonia. Past studies have emphasized controlling negative affect, but there is an emerging trend in the depression literature to focus on positive emotion. The current study employed several psychophysiological tools, postauricular reflex, startle blink reflex, and event-related potential (ERP) components such as P3 and the late positive potential (LPP), to assess the dissociable components in positive emotion (consummatory and anticipatory processes). In addition, several different hypotheses of emotional dysfunction were evaluated to accurately model deficits in positive emotionality. A majority of the psychophysiological tools used supported …

Power America's — And Nevada's — Advanced Industries: State By State, Region By Region, Mark Muro

Brookings Scholar Lecture Series

With the U.S. economy still flat, economic experts and leaders continue to search for the next source of U.S. and regional growth. One key component of the next era of prosperity can be projected: It is what the Brookings Metropolitan Policy Program calls the advanced industry (AI) sector. The nation’s most strategic R&D — and STEM worker intensive industries, AIs like aerospace and IT are prime movers of regional and national prosperity, because they are key sources of technology innovation and generate domestic and international exports. Accordingly, the AI swatch of 50 discrete industries has emerged as an important new …

Epa's Proposed Greenhouse Gas Regulation For Power Plants: How Does It Work And What Will It Mean For Nevada?, Adele C. Morris

Brookings Scholar Lecture Series

In June, the Environmental Protection Agency proposed important new limits on carbon dioxide emissions from existing U.S. power plants. The new regulation is the centerpiece of the Obama Administration’s climate policy. If the controversial rule is finalized as planned next year, it will cover about a third of U.S. greenhouse gas emissions. This lecture will explain the legal, environmental, and economic issues posed by the rule and highlight the important role for states in implementing it. The lecture will also review the implications and options for achieving the emissions target the EPA set for Nevada.

The Shortage Of Skilled Workers: Quality Jobs For A Trained Workforce, Jonathan Rothwell

Brookings Scholar Lecture Series

The Great Recession of 2008 temporarily solved employer workforce needs by lowering demand and increasing the number of unemployed skilled workers. After a few years of modest but sustained economic growth, the labor market for skilled workers has once again tightened and positions are going unfilled. This research helps national and regional leaders understand which skills are in short supply and offers policy advice on how to redress the imbalance between supply and demand. In addition to offering a national perspective on this topic, the lecture will examine the situation in Nevada.

A Taxonomy Of Polynomially Solvable Shop Problems With Limited Number Of Machines Or Jobs, Megha Sairam Darapuneni

UNLV Theses, Dissertations, Professional Papers, and Capstones

Among shop scheduling problems, job shop and mixed shop are one of the most general models encompassing open shop and flow shop. Many job shop problems are NP hard, but there are numerous cases, which possess polynomial solutions when the number of jobs or the number of machines (or both) is limited.

This thesis gives an overview of methods and algorithms for solving - in polynomial time - such special shop problems, including open, flow, job shop and mixed shop. The tools used include Monge interchange, dynamic programming, greedy techniques and sweep line algorithms and the primary focus of this …