Digital Commons Network^™

Predictive Modeling Of Terrestrial Radiation Exposure From Geologic Materials, Daniel A. Haber

UNLV Theses, Dissertations, Professional Papers, and Capstones

Aerial gamma ray surveys are an important tool for national security, scientific, and industrial interests in determining locations of both anthropogenic and natural sources of radioactivity. There is a relationship between radioactivity and geology and in the past this relationship has been used to predict geology from an aerial survey. The purpose of this project

is to develop a method to predict the radiologic exposure rate of the geologic materials in an area by creating a model using geologic data, images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), geochemical data, and pre-existing low spatial resolution aerial surveys …

Solving Differential Equations With Least Square And Collocation Methods, Katayoun Bodouhi Kazemi

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this work, we first discuss solving differential equations by Least Square Methods (LSM). Polynomials are used as basis functions for first-order ODEs and then B-spline basis are introduced and applied for higher-order Boundary Value Problems (BVP) and PDEs. Finally, Kansa's collocation methods by using radial basis functions are presented to solve PDEs numerically. Various numerical examples are given to show the efficiency of the methods.

Differences In Disease Reporting: An Analysis Of State Reportable Conditions And Their Relationship To The Nationally Notifiable Conditions List, Brian Labus

UNLV Theses, Dissertations, Professional Papers, and Capstones

The basis of public health surveillance is the reporting of diseases and conditions to the health department by clinicians and laboratories. In the United States, over eighty diseases and conditions of national importance (e.g., tuberculosis, syphilis, and cancer) are included on the list of Nationally Notifiable Conditions (NNC) for submission to the Centers for Disease Control and Prevention (CDC) by the states. The legal basis for disease reporting is found at the state level, where inconsistent laws may differ in terms of which conditions are reportable and their reporting process. The process by which states require the reporting of NNCs …

The Roman Inquisition: Trying Galileo, Maurice A. Finocchiaro

Philosophy Faculty Research

No abstract provided.

An Investigation Into Transitions In Clay Mineral Chemistry On Mars, Seth Gainey

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation is comprised of three studies investigating clay mineralogy on, or near the martian surface, with an introductory chapter, introducing and linking the three studies. Chapter two is on the subject of clay mineral synthesis, including Fe/Mg clay minerals which have been detected at multiple locations across the southern highlands. These Fe/Mg clay minerals have been previously interpreted as forming in anoxic/reducing environments, conducive to the preservation of organic matter. The results of this study suggest that the previous interpretation of Fe/Mg-rich clay as requiring anoxic/reducing conditions may not be accurate, as the minor presence of Mg (below what …

Efficient Noninferiority Testing Procedures For Simultaneously Assessing Sensitivity And Specificity Of Two Diagnostic Tests, Guogen Shan, Amei Amei, Daniel Young

Environmental & Global Health Faculty Research

Sensitivity and specificity are often used to assess the performance of a diagnostic test with binary outcomes. Wald-type test statistics have been proposed for testing sensitivity and specificity individually. In the presence of a gold standard, simultaneous comparison between two diagnostic tests for noninferiority of sensitivity and specificity based on an asymptotic approach has been studied by Chen et al. (2003). However, the asymptotic approach may suffer from unsatisfactory type I error control as observed from many studies, especially in small to medium sample settings. In this paper, we compare three unconditional approaches for simultaneously testing sensitivity and specificity. They …

Inverse Problem For Non-Viscous Mean Field Control: Example From Traffic, Shaurya Agarwal

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis presents an inverse problem for mean field games where we find the

mean field problem statement for which the given dynamics is the solution. We use

distributed traffic as an example and derive the classic Lighthill Whitham Richards

(LWR) model as a solution of the non-viscous mean field game. We also derive

the same model by choosing a different problem where we use travel time, which

is a distributed parameter, as the cost for the optimal control. We then study the

stationary versions of these two problems and provide numerical solutions for the

same.

Versatile Synthetic Methods For Photoluminescent Pyrylium Tosylates, Jung Jae Koh

UNLV Theses, Dissertations, Professional Papers, and Capstones

Pyrylium salts are an important class of cationic organic molecules that exhibit good absorption, fluorescence, and photo-induced electron transfer properties. They can also function as precursors for synthesis of different heterocyclic organic molecules such as furan, pyridine, pyridinium salt, and betaine dyes. This thesis describes versatile methods of synthesis for a series of 2,4,6-triarylsubstitued pyrylium tosylates with different substituents by using p-toluenesulfonic acid monohydrate instead of conventional acid catalysts including perchloric acid or boron trifluoride diethyl etherate that accompany explosion danger and difficult storage problem, respectively. The chemical structures were established by ¹H and ¹³C NMR spectroscopic techniques …

Educators’ Perspectives Associated With School Garden Programs In Clark County, Nevada: Practices, Resources, Benefits And Barriers., Tomomi Murakami

UNLV Theses, Dissertations, Professional Papers, and Capstones

School garden programs have been utilized in the U.S. since their introduction at the end of the 19th century. The use of school gardens and the teaching style implemented in them are dependent on individual schools and teachers. Educators’ attitudes, knowledge, and motivation for a school-based gardening program are crucial to implementing comprehensive school garden programs. To move toward an expansion of garden education, it is necessary to determine the concerns, resources, benefits or barriers that educators identify regarding the utilization of gardens to teach their students. The purpose of this pilot study was to determine principals’ and teachers’ perceived …

A Study Of Elementary Teachers’ Conceptions Of Nature Of Science And Their Beliefs About The Developmental Appropriateness And Importance Of Nature Of Science Throughout A Professional Development Program, Elif Adibelli

UNLV Theses, Dissertations, Professional Papers, and Capstones

This qualitative study aimed to explore the changes in elementary science teachers’ conceptions of nature of science (NOS) and their beliefs about the developmental appropriateness and importance of NOS after participating in an academic, year-long professional development program (PDP) as well as the factors facilitating these changes. The PDP consisted of two phases. In the first phase, the participants received NOS training designed with an explicit-reflective instructional approach. In the second phase, the participants implemented several NOS training activities in their classrooms. Four elementary science teachers who volunteered and completed all components of the PDP (i.e., the NOS training and …

Robust Observability, Control, & Economics Of Complex Cyber-Physical Networks, Shaurya Agarwal

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation deals with various aspects of cyber-physical system. As an example of cyber physical systems, we take transportation networks and solve various problems, namely: 1) Network Observability Problem, 2) Network Control Problem, and 3) Network Economics Problem. We have divided the dissertation into three parts which solve these three problems separately. First part of the dissertation presents a novel approach for studying the observability problem on a general network topology of a traffic network. We develop a new framework which investigates observability in terms of flow information on arcs and the routing information. Second part of the dissertation presents …

Structure And Optical Properties Of Transition Metal Dichalcogenides (Tmds) – Mx2 (M = Mo, W & X = S, Se) Under High Pressure And High Temperature Conditions, Nirup Reddy Bandaru

UNLV Theses, Dissertations, Professional Papers, and Capstones

Layered structured materials such as transition metal dichalcogenides (TMDs) have gained immense interest in recent times due to their exceptional structural, electrical and optical properties. Recent studies show semiconducting TMDs such as MX₂ (M= Mo, W & X = S, Se) could be used as potential shock absorbing material, which has resulted in extensive studies on structural stability of these materials under the influence of high pressure. Understanding the structural stability of transition metal dichalcogenides (TMDs) such as MoS2, MoSe2, WS2, and WSe2 under high pressure has been very challenging due to contradicting observations and interpretations reported in the …

Data Analysis With Map Reduce Programming Paradigm, Mandana Bozorgi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Abstract In this thesis, we present a summary of our activities associated with the storage and query processing of Google 1T 5-gram data set. We rst give a brief introduction to some of the implementation techniques for the relational algebra followed by a Map Reduce implementation of the same operators. We then implement a database schema in Hive for the Google 1T 5-gram data set.

The thesis will further look into the query processing with Hive and Pig in the Hadoop setting.

More specially, we report statistics for our queries in this environment.

Laser Ablation Icp-Ms Of Actinide Oxides As Simulated Used Nuclear Fuels, Keri Campbell

UNLV Theses, Dissertations, Professional Papers, and Capstones

The ability to examine elemental and isotopic ratios of fuels, waste forms, and other solids by direct analysis using laser ablation techniques can greatly reduce analysis costs and time. This is particularly true for actinide elements, as they contain useful information of the fuel cycle and nuclear forensics. Current methods to evaluate the composition of used fuel include a lengthy process of digestion, separations and often require multiple techniques and sample preparations to determine the elemental and isotopic composition. Furthermore all spatial information is lost during the digestion process, eliminating potentially useful data for detailed analysis. The goal of this …

Kinematics And Timing Of The Miocene-Quaternary Deformation In Nellis Dunes Recreational Area, Nevada, Shaimaa Abdelhaleem

UNLV Theses, Dissertations, Professional Papers, and Capstones

The kinematics and origin of transfer, accommodation and strike-slip zones is of paramount significance in understanding continental extension. The Las Vegas Valley Shear Zone (LVVSZ) is a NW-striking right-lateral fault system in the central Basin and Range province. Despite its prominence among the structures of the region and its role in the regional tectonic development, little is understood about its eastern portion. The inadequately constrained trace of the LVVSZ along its eastern part contributes largely to the ambiguity of the time activity and role of the LVVSZ. The eastern part of LVVSZ lies in Nellis Dunes Recreational Area (NDRA), north …

The Development Of Language And Identity: A Sociocultural Study Of Five International Graduate Students Living In The U.S., Alexandra Dema

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this sociocultural study was to analyze the longitudinal process of identity development of international graduate students as their lives unfolded across time and experience in the second languaculture. Furthermore, it was aimed at exploring what role is attributed to second language in this process. The study relied on the mainstream sociocultural perspectives on individual development that originated from Vygotsky’s work and were further elaborated by his followers to address the issues of identity and language development of second language learners. As part of such perspectives, it integrated the unit of perezhivanie into the examination of individual experiences …

Stable Isotope Analysis Of Bison Latifrons And Paleoecological Inferences, Fabian Ceron Hardy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Bison latifrons was a large Pleistocene herbivore that is traditionally hypothesized to have been adapted to living in forest openings and woodlands. According to this view, the species was primarily a browser of high-growing, woody plants. Very little isotopic work has been conducted on this species, and there have been no prior studies of high altitude localities containing this species. This study aims to address both of these issues.

B. latifrons is known from sites in several states, including California, Idaho, Colorado, Nevada, and Florida, among others. These sites provide diverse examples of this species’ habitat and the opportunity to …

States And Multicultural Education Policies: An Event History Analysis, Leander D. Kellogg

UNLV Theses, Dissertations, Professional Papers, and Capstones

Multicultural education policies related to K-12 curriculum have been shown to benefit underperforming students. This research found that 10 states have adopted such policies between 1978 and 1994. A unified model of policy innovation and diffusion with a conceptual framework, which included three factors: motivation to innovate, obstacles to innovation, and resources to overcome such obstacles was used to explore demographic, political, and economic conditions along with neighboring states diffusion. Both internal and external determinants were found to significantly influence the adoption of multicultural education. Specifically, states with slightly less education funding were more likely to adopt a policy. Additionally, …

Hydrothermal Routes To Technetium Cluster Compounds, William M. Kerlin

UNLV Theses, Dissertations, Professional Papers, and Capstones

Transition metals of groups six through nine exhibit unique direct multiple metal-metal bonding cores. Technetium is a group seven transition metal and is the lightest radioelement in the periodic table. Technetium exhibits nine oxidation states (from -I to VII) and an extensive set of mixed oxidation states due to bi- or poly- nuclear complex formation. Technetium has no stable isotopes and thirty four technetium isotopes have been discovered. Two main isotopes are of great importance ⁹⁹Tc and its metastable nuclear isomer ^99mTc. The isotope ^99mTc (T_1/2 = 6.01 hours, γ = 140.5 keV) is used in …

Development Of A Decision Support Framework For The Planning Of Sustainable Transportation Systems, Pankaj Maheshwari

UNLV Theses, Dissertations, Professional Papers, and Capstones

With the rapid increase in economic development throughout the world, there is stress on the resources used to support global economy, including petroleum, coal, silver, and water. Currently, the world is consuming energy at an unprecedented rate never seen before. The finite nature of such non-renewable natural resources as petroleum and coal puts pressure on the environmental system, and ultimately reduces the availability of resources for future generations. Hence, it is critical to develop planning and operational strategies that seek to achieve a sustainable use of existing natural resources.

With this motivation, this dissertation focuses to develop a decision support …

Feasibility Study Of Custom Manufacturing Of Ionic Polymer-Metal Composite Sensors, Shelby E. Nelson

UNLV Theses, Dissertations, Professional Papers, and Capstones

The ability to create an ion exchange membrane with any shape or thickness through custom manufacturing techniques is highly desirable in ionic polymer-metal composite (IPMC) research. This is caused by the poor selection and limited availability of certain thicknesses of commercial ion exchange membranes. The objective of this study is to determine the feasibility of manufacturing custom ion exchange membranes for IPMC sensors. The manufacturing methods used in this study are extrusion, injection molding, and hot pressing. A commercial membrane from Golden Energy Fuel Cells (GEFC) is used as a comparison. After the membranes are fabricated, certain properties of the …

General Application Of Smart Inverters In Distribution And Smart Grid, Wenxin Peng

UNLV Theses, Dissertations, Professional Papers, and Capstones

The electric grid of the near future will face challenges and opportunities based on two aspects. First, the rapid growth of renewable generations expedites the upgrading of traditional electric grids, allowing more and more distributed generation connected at the customers’ side. Distributed generation units use a wide range of generation technologies, including gas turbines, diesel engines, solar photovoltaics (PV), wind turbines, fuel cells, biomass, and small hydroelectric generators. Under certain penetration level, the grid will experience issues like unexpected voltage rise as well as reverse power flows due to the fluctuation of power production of the distributed generation, especially when …

Retroactive Interference In Recognition Memory: The Effects Of Mental Effort And Similarity On Recollection And Familiarity, Caleb Jordan Picker

UNLV Theses, Dissertations, Professional Papers, and Capstones

Learning new material may retroactively interfere with memory for older material. Retroactive interference research has typically focused on how similarity between old and new material affects recall of old material, which predicts greatest interference when similar material is presented just before test. However, mental effort may be another source of retroactive interference that could disrupt consolidation: Mental effort could cause the most retroactive interference when presented just after study. In Experiment 1, participants engaged in tasks designed to induce mental effort (e.g., solving easy or difficult math problems) at various times between the study and test of an associative recognition …

Cfd Simulation Of Heat Enhancement In Internally Helical Grooved Tubes, Sogol Pirbastami

UNLV Theses, Dissertations, Professional Papers, and Capstones

Heat exchanger devices are widely used in industries, air conditioning systems, refrigeration, etc. These devices have a major role in energy conservation; therefore, increasing the performance of heat exchangers helps save energy, costs and materials. The technique to increase the heat transfer performance is called heat augmentation, which can be applied to pipe surfaces and other surfaces which are used in heat exchangers to improve thermal performance. These techniques are categorized into 3 groups: passive, active and compound technique. In this study a helically machined rectangular groove on the inside of a 2.0 m tube with a diameter of 7.1mm …

Engineering The Path To Higher-Order Thinking In Elementary Education: A Problem-Based Learning Approach For Stem Integration, Abeera P. Rehmat

UNLV Theses, Dissertations, Professional Papers, and Capstones

As we progress into the 21^st century, higher-order thinking skills and achievement in science and math are essential to meet the educational requirement of STEM careers. Educators need to think of innovative ways to engage and prepare students for current and future challenges while cultivating an interest among students in STEM disciplines. An instructional pedagogy that can capture students’ attention, support interdisciplinary STEM practices, and foster higher-order thinking skills is problem-based learning. Problem-based learning embedded in the social constructivist view of teaching and learning (Savery & Duffy, 1995) promotes self-regulated learning that is enhanced through exploration, cooperative social activity, …

The Convergence Of Structure And Design Between Video Games And Video Gambling, Daniel Sahl

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study looks at the incorporation of video game design and structure into contemporary slot machines. The investigation was guided by theoretical and empirical works from a range of scholarly fields: gambling studies, video-game studies, digital communication, psychology, and sociology. Two methodological designs were employed. The first phase used a content analysis that identified the distribution of video-game styles and design in the most recent slot games on display at a major industry conference. The second phase employed semi-structured interviews with both experienced and inexperienced slot players to assess the impact of different design elements on their playing experience and …

Constructing Bfs Trees Using Tokens To Balance Speed And Network Traffic, Michael Spencer

UNLV Theses, Dissertations, Professional Papers, and Capstones

Constructing BFS trees rooted at each node of a network helps solve many problems. Reliable communication to other nodes is easily managed and metrics such as the network diameter, shortest path between any two nodes, the center, the radius, and others can be easily computed. A traditional way to form a BFS tree from each node is for all nodes to construct their trees in parallel. While this is the fastest way to accomplish this task, it also requires a large amount of network traffic. In this thesis, we present a way to use a token passing algorithm to form …

The Presence Of Clostridium Difficile On Environmental Surfaces In Healthcare Facilities Pre- And Post-Decontamination Of Patient Rooms, Theresa Trice

UNLV Theses, Dissertations, Professional Papers, and Capstones

Healthcare-associated infections (HAIs) are infections related to receiving medical care. HAIs are responsible for an excess of morbidity and mortality among hospitalized patients. Though most HAIs rates are on the decline, Clostridium difficile infection rates are at an all-time high, primarily due to the persistence of C. difficile spores in the environment. In the United States, Clostridium difficile-related mortality rates per million have increased from 5.7 in 1999 to 23.7 in 2004, with an estimated 26,642 deaths due to Clostridium difficile infections (CDIs). Clostridium difficile is transmitted via the fecal-oral route or aerosolized endospores, but it can also be transmitted …

A Survey Of Network Coding And Applications, Jonny L. Winger

UNLV Theses, Dissertations, Professional Papers, and Capstones

Common networks with source, internal, and destination nodes put data packets in queues for forwarding.Network coding aims to improve network throughput and energy consumption by combining received data packets before forwarding. In this survey, we will explore various network coding schemes, along with the behavior of network coding in applications. Sensor, wireless routing, and distributed storage networks can benefit greatly from network coding implementations. Flooding is a procedure in distributed systems which broadcasts a message to all nodes in the network. NC-Flooding is introduced, which uses network coding to possibly decrease the message complexity and/or time complexity of flooding.

High Pressure Phase-Transformation Induced Texture Evolution And Strengthening In Zirconium Metal: Experiment And Modeling., Xiaohui Yu, Yusheng Zhao, Ruifeng Zhang, David Weldon, Sven C. Vogel, Jianzhong Zhang, Donald W. Brown, Yanbin Wang, Helmut M. Reiche, Shanmin Wang, Shiyu Du, Changqing Jin

Physics & Astronomy Faculty Research

We studied the phase-transition induced texture changes and strengthening mechanism for zirconium metal under quasi-hydrostatic compression and uni-axial deformation under confined high pressure using the deformation-DIA (D-DIA) apparatus. It is shown that the experimentally obtained texture for ω-phase Zr can be qualitatively described by combining a subset of orientation variants previously proposed in two different models. The determined flow stress for the high-pressure ω-phase is 0.5–1.2 GPa, more than three times higher than that of the α-phase. Using first-principles calculations, we investigated the mechanical and electronic properties of the two Zr polymorphs. We find that the observed strengthening can be …