Physical Sciences and Mathematics Commons^™

Neither The Washington Nor Beijing Consensus: Developmental Models To Fit African Realities And Cultures, Sanusi L. Sanusi

CBN Journal of Applied Statistics (JAS)

No abstract provided.

Review Of Sandhill And Whooping Cranes: Ancient Voices Over America's Wetlands By Paul Johnsgard, Jane E. Austin

The Prairie Naturalist

Paul Johnsgard has long been captivated by wild cranes and their unique vocalizations, courtship dances, and wide-ranging migrations. As a scientist and an admirer, Johnsgard has watched their migrations and behaviors for decades as hundreds of thousands of cranes staged each spring by the central Platte River, not far from his home in Lincoln, Nebraska. As an artist, he has skillfully captured their courtship dances and other behaviors in his exceptional line drawings. And, as an author, he has written extensively on their ecology in three earlier books: Cranes of the World (1983), Those of the Gray Wind: The Sandhill …

Book Review: Effects Of Climate Change On Birds, Edited By Anders Pape Meller, Wolfgang Fiedler, And Peter Berthold, Brian J. Olsen

The Prairie Naturalist

Book review of Effects of Climate Change on Birds, edited by Anders Pape Meller, Wolfgang Fiedler, and Peter Berthold.

Climate scientists from across the globe predict vast changes during the next century in the planet's temperatures, precipitation, storm intensities, fire regimes, hydrologic cycles, and atmospheric, water, and soil chemistries. The changes will be global, but their effects will be felt locally everywhere. To find a scientifically and socially engaging bellwether of these events, we need to look only through the lens of avian biology. Birds are found from pole to pole; their movements connect continents. They are loud, colorful …

Application Oriented Analysis Of Large Scale Datasets, Prashant Shivaji Paymal

Student Work

Diverse application areas, such as social network, epidemiology, and software engineering consist of systems of objects and their relationships. Such systems are generally modeled as graphs. Graphs consist of vertices that represent the objects, and edges that represent the relationships between them. These systems are data intensive and it is important to correctly analyze the data to obtain meaningful information. Combinatorial metrics can provide useful insights for analyzing these systems. In this thesis, we use the graph based metrics such as betweenness centrality, clustering coefficient, articulation points, etc. for analyzing instances of large change in evolving networks (Software Engineering), and …

Precisely Serializable Snapshot Isolation, Stephen Anthony Revilak

Graduate Doctoral Dissertations

Snapshot Isolation (SI) is a method of database concurrency control that uses timestamps and multiversioning, in preference to pessimistic locking. Since its introduction in 1995, SI has become a popular isolation level, and has been implemented in a variety of database systems: Oracle, Postgres, Microsoft SQL Server, and others. Despite the benefits that SI offers, one of the things it cannot provide is serializability. Past approaches for serializable SI have focused on avoiding dangerous structures (or essential dangerous structures). Dangerous structures are patterns of transaction dependencies that indicate the potential for a non-serializable execution; however, the presence of dangerous structures …

Concept Tests For A New Wire Flying Vehicle Designed To Achieve High Horizontal Resolution Profiling In Deep Water, Chris Roman, Dave Hebert

Graduate School of Oceanography Faculty Publications

Efficiently profiling the water column to achieve both high vertical and horizontal resolution from a moving vessel in deep water is difficult. Current solutions, such as CTD tow-yos, moving vessel profilers, and undulating tow bodies, are limited by ship speed or water depth. As a consequence, it is difficult to obtain oceanographic sections with sufficient resolution to identify many relevant scales over the deeper sections of the water column. This paper presents a new concept for a profiling vehicle that slides up and down a towed wire in a controlled manner using the lift created by wing foils. The wings …

Estimating Oil Concentration And Flow Rate With Calibrated Vessel-Mounted Acoustic Echo Sounders, Thomas C. Weber, Alex De Robertis, Shep Smith, Samuel F. Greenaway, Larry A. Mayer, Glen Rice

Center for Coastal and Ocean Mapping

As part of a larger program aimed at evaluating acoustic techniques for mapping the distribution of subsurface oil and gas associated with the Deepwater Horizon-Macondo oil spill, observations were made on June 24 and 25, 2010 using vessel-mounted calibrated single-beam echo sounders on the National Oceanic and Atmospheric Administration ship Thomas Jefferson. Coincident with visual observations of oil at the sea surface, the 200-kHz echo sounder showed anomalously high-volume scattering strength in the upper 200 m on the western side of the wellhead, more than 100 times higher than the surrounding waters at 1,800-m distance from the wellhead, …

An Embedded Atom Method Investigation Into The Lattice Dynamics Of Metallic Surfaces, Richard B. Wilson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The explosion in electronic devices over the last half century is a result of the successful development and application of theories that explain the physical properties of solids. For example, the theory of lattice vibrations developed in the first half of the 20^th century has had a huge impact on our ability to understand and design devices. The idea that atoms vibrate together in grouped vibrational modes, called phonons, has enabled scientists to quantify the impact that atomic motion has on mechanical, thermal, electrical, and optical properties. This has aided the creation of all sorts of useful technology ranging …

A Dynamic State Metabolic Journey: From Mass Spectrometry To Network Analysis Via Estimation Of Kinetic Parameters, Arockia Ranjitha Dhanasekaran

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The term "metabolism" refers to the chemical processes occurring in a living organism to convert the food consumed into the energy needed to maintain a living state. Metabolism consists of two states, namely, a dynamic state and a steady state. In the dynamic state, the rate of chemical conversion of a substance is proportional to the amount of substance available, whereas in the steady state this rate is constant and independent of the amount of substance present (Chapter 4 Figure 1). Like all other fields of engineering, metabolic engineering involves the analysis and synthesis of metabolism. Molecular biological tools for …

Accelerating Production Of Slow-Growing Intermountain West Native Plants By Modifying Their Microclimate, Sam A. Miller

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Water shortages are a recurring problem in the western US. As much as 70% of yearly municipal water consumption may be used to irrigate urban landscapes. Significant water savings can be realized by installing low water landscapes, where turfgrass is replaced by low water trees, shrubs, grasses, and perennials. Intermountain West (IMW) native trees and shrubs are excellent candidates for low water landscaping. However, due to their slow initial growth, many native trees and shrubs are simply unavailable to consumers, as they are not cost effective for nursery growers to produce. In an effort to accelerate the yearly growth rates …

The Interrelationship Between The Bio- And Sequence Stratigraphy Of The Middle Cambrian Spence Shale Of Northern Utah And Southern Idaho, Eva Lyon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This project was undertaken with the objective of discerning the relationship between sea level change and changes in the fauna of the Spence Shale. A combination of field and lab work was employed to undertake this research. The Spence Shale is rich in fossils from the earliest period of visible life on this planet. It provides a unique window onto the evolution of life and changes in the Earth at this time. It is important to study this relationship between sea level and life changes as these conditions are constantly changing, particularly in this day and age. A better understanding …

Determining Co2 Storage Potential: Characterization Of Seal Integrity And Reservoir Failure In Exposed Analogs, Daniel Corey Barton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sequestration of carbon dioxide (CO₂) into subsurface porous sandstone is proposed as a method for reducing accumulation of anthropogenic emissions of CO₂ into the atmosphere. Natural exposures of reservoir and top-seal pairs in central and southeastern Utah are identified as analogs to proposed CO₂ injection targets. Reservoir and top-seal pairs in natural analog exposures are analyzed in tandem to evaluate evidence for paleo-migration of fluids and/or hydrocarbons from the reservoir through the top seal. The San Rafael Swell and Monument Uplift exhibit similar structure and exposures of Jurassic units yet differ in amount and type of …

Front Matter

The Synapse: Intercollegiate science magazine

No abstract provided.

Alohamora! Unlocking Magic With The Wonders Of Science, Anna Dardick

The Synapse: Intercollegiate science magazine

No abstract provided.

What's Up, Weelic?: Tracking Neural Pathways With A Sugar-Coated Virus, Weelic Chong

The Synapse: Intercollegiate science magazine

No abstract provided.

This Is Your Brain On Acetylcholine, Ksenia Vlasov

The Synapse: Intercollegiate science magazine

No abstract provided.

What Are Friends For?: The Importance Of Friend Groups In Academic Success, Emily Neuhoff

The Synapse: Intercollegiate science magazine

No abstract provided.

Mike Got A Bigger Bike: Mike Rauscher On Nuclear Space Travel, Quinton Steele

The Synapse: Intercollegiate science magazine

No abstract provided.

Honors Research, Matt Hartsock, Sam Asinof, Sage Aronson, Yuhua Lu

The Synapse: Intercollegiate science magazine

No abstract provided.

Electrolyte Incorporation Into Composite Electrodes For Proton-Exchange Membrane Fuel Cells And Lithium-Ion Batteries, Jung Oh

All Dissertations

This dissertation describes research on the preparation and characterization of composite electrodes for use in proton-exchange membrane (PEM) fuel cells and lithium ion batteries. The general focus of the research was on high-surface-area carbon supports for platinum catalysts in fuel cells, and integration of electrolytes, particularly fluoropolymer electrolytes, into composite electrodes both batteries and fuel cells. Results are described for work in the following three specific topical areas.
1. Carbon nanofibers for use as platinum (Pt) catalyst supports in fuel cells were prepared by carbonization of electrospun acrylic fibers. The resulting carbon nanofibers were found to contain mainly micropores. Following …

Time-Interval Analysis For Radiation Monitoring, Peng Luo

All Dissertations

On-line radiation monitoring is essential to the U.S. Department of Energy (DOE) Environmental Management Science Program for assessing the impact of contaminated media at DOE sites. The goal of on-line radiation monitoring is to quickly detect small or abrupt changes in activity levels in the presence of a significant ambient background. The focus of this research is on developing effective statistical algorithms to meet the goal of on-line monitoring based on time-interval (time-difference between two consecutive radiation pulses) data. Compared to the more commonly used count data which are registered in a fixed count time, time-interval data possess the potential …

The Toxicity Of Carbon Nanotubes To Daphnia Magna, Aaron Edgington

All Dissertations

A particle is classified as nano in size if it has at least one dimension less than 100 nm which gives them chemical and physical characteristics that are different from the bulk material. Over the last twenty years nanotechnology has exploded as an industry. It has been estimated that there are 1000 consumer products on the market today that contain nanomaterials and 2 million jobs worldwide will be devoted directly to nanotechnology research, development, and product manufacturing by 2015. Carbon nanotubes (CNTs) can be visualized as sheets of graphene rolled into a cylinder. Carbon nanotubes small diameter (nanometer scale) and …

The Design & Implementation Of An Abstract Semantic Graph For Statement-Level Dynamic Analysis Of C++ Applications, Edward Duffy

All Dissertations

In this thesis, we describe our system, Hylian, for statement-level analysis,
both static and dynamic, of a C++ application. We begin by extending the
GNU gcc parser to generate parse trees in XML format for each of the
compilation units in a C++ application. We then provide verification that the
generated parse trees are structurally equivalent to the code in the
original C++
application. We use the generated parse trees, together with an augmented
version of the gcc test suite, to recover a grammar for the C++ dialect that
we parse. We use the recovered grammar to generate a schema …

Nitrogen Retention And Denitrification In Reservoirs, Erin Grantz

Graduate Theses and Dissertations

Studies coupling direct measurements of micro-scale nitrogen (N) cycle processes with ecosystem-scale flux estimates are needed to determine N retention hotspots within river networks, where up to 50% of terrestrial loading to aquatic systems is retained. This study examined the role of denitrification, a microbially-mediated reactive N removal pathway, in ecosystem-scale N retention in 3 small (< 1 km2), shallow flood-control reservoirs. Annual reservoir N retention was estimated through mass balance modeling of system inputs and outputs. Annual denitrification rates were estimated by combining multiple measurements of seasonal, habitat-specific dinitrogen gas (N2) fluxes. Annual reservoir N retention ranged from 14 - 19 g m-2 in the reservoirs, while reactive N removal through denitrification was 13 - 25 g m-2. Denitrification efficiency, or the portion of the retained N load that was denitrified, was high relative to other lentic systems and was > 100% at 2 sites. Previous lentic denitrification studies may have underestimated denitrification efficiency by not considering water column denitrification, which was 50% of total denitrification at one study reservoir. However, not all potential inputs, most importantly biological N2 fixation, were included in this …

Characterization And Discrimination Of Large Caliber Gun Blast And Flash Signatures, Bryan J. Steward

Theses and Dissertations

Two hundred and one firings of three 152 mm howitzer munitions were observed to characterize firing signatures of a large caliber gun. Muzzle blast expansion was observed with high-speed (1600 Hz) optical imagery. The trajectory of the blast front was well approximated by a modified point-blast model described by constant rate of energy deposition. Visible and near-infrared (450 - 850 nm) spectra of secondary combustion were acquired at 0.75 nm spectral resolution and depict strong contaminant emissions including Li, Na, K, Cu, and Ca. The O2 (X-b) absorption band is evident in the blue wing of the potassium D lines …

Aquatic Plant Surveys In The Bureau Of Land Management, Medford District, 2010-2011, Mark D. Sytsma, Rich Miller, Vanessa Morgan

Center for Lakes and Reservoirs Publications and Presentations

The introduction of invasive aquatic plant species (IAPS) can cause significant ecological and economic harm. IAPS can displace native aquatic plant species, impair recreation, and degrade water quality. Early detection of new invasions can improve chances for successful eradication or containment to reduce the risk of IAPS spread. The Oregon Department of Agriculture (ODA) lists the most egregious offenders as “Noxious Weeds” which are defined as plants classified by the Oregon State Weed Board that are injurious to public health, agriculture, recreation, wildlife, or any public or private property (ODA 2011).

Several IAPS classified as noxious have been detected within …

Automating Construction And Selection Of A Neural Network Using Stochastic Optimization, Jason Lee Hurt

UNLV Theses, Dissertations, Professional Papers, and Capstones

An artificial neural network can be used to solve various statistical problems by approximating a function that provides a mapping from input to output data. No universal method exists for architecting an optimal neural network. Training one with a low error rate is often a manual process requiring the programmer to have specialized knowledge of the domain for the problem at hand.

A distributed architecture is proposed and implemented for generating a neural network capable of solving a particular problem without specialized knowledge of the problem domain. The only knowledge the application needs is a training set that the network …

Spectroscopic Methods Of Process Monitoring For Safeguards Of Used Nuclear Fuel Separations, Jamie Lee Warburton

UNLV Theses, Dissertations, Professional Papers, and Capstones

To support the demonstration of a more proliferation-resistant nuclear fuel processing plant, techniques and instrumentation to allow the real-time, online determination of special nuclear material concentrations in-process must be developed. An ideal materials accountability technique for proliferation resistance should provide nondestructive, realtime, on-line information of metal and ligand concentrations in separations streams without perturbing the process. UV-Visible spectroscopy can be adapted for this precise purpose in solvent extraction-based separations.

The primary goal of this project is to understand fundamental URanium EXtraction (UREX) and Plutonium-URanium EXtraction (PUREX) reprocessing chemistry and corresponding UV-Visible spectroscopy for application in process monitoring for safeguards. By …

Being Outside Learning About Science Is Amazing: A Mixed Methods Study, Michelle L. Weibel

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study used a convergent parallel mixed methods design to examine teachers' environmental attitudes and concerns about an outdoor educational field trip. Converging both quantitative data (Environmental Attitudes Scale and teacher demographics) and qualitative data (Open-Ended Statements of Concern and interviews) facilitated interpretation. Research has shown that adults' attitudes toward the environment strongly influence children's attitudes regarding the environment. Science teachers' attitudes toward nature and attitudes toward children's field experiences influence the number and types of field trips teachers take. Measuring teacher attitudes is a way to assess teacher beliefs.

The one day outdoor field trip had significant outcomes for …

A Landscape Approach To Late Prehistoric Settlement And Subsistence Patterns In The Mojave Sink, Tiffany Ann Thomas

UNLV Theses, Dissertations, Professional Papers, and Capstones

The environment of the Late Prehistoric period (1200 A.D. to Historic Contact) Mojave Sink was wetter than modern conditions. The settlement and subsistence patterns of the occupants of the region during this period were driven by the availability of water, subsistence resources, raw material sources, and tradition. These people utilized the regional landscape based upon the seasonal availability of these resources. Supplemental agricultural production has been proposed for the Mojave River Delta due to the more favorable environmental conditions of this period. If agriculture was being practiced it would have affected the regional land-use patterns. For this thesis I propose …