Physical Sciences and Mathematics Commons^™

Assessing Eolian Dust Inputs To Soils In Dry Creek Experimental Watershed, Sw Idaho, Brian Jameson Stark

Boise State University Theses and Dissertations

A geochemical investigation of upland soils in the Dry Creek Experimental Watershed (DCEW) near Boise, Idaho was conducted to assess the potential contributions of eolian dust. Major and trace element compositions of soils within the watershed, loess deposits in the adjacent Western Snake River Plain (WSRP), and underlying granodiorite bedrock were evaluated. Multiple lines of evidence suggest a significant contribution of dust in the soils. Plots of Co/Ti, V/Ti and Cr/Ti indicate that the loess and bedrock occupy distinctly different compositional spaces and that the soils are of intermediate composition, suggesting that the soils are a mixture of the loess …

Lidar Investigations Of Snow Distribution In Mountainous Terrain, Alden Taylor Shallcross

Boise State University Theses and Dissertations

An algorithm is constructed to use snow-depth estimates, derived from repeat airborne LiDAR (Light Detection and Ranging), to identify the sampling strategy that requires the fewest total measurements to estimate the total snow volume in the Dry Creek Experimental Watershed (DCEW) Idaho. LiDAR is used to map snow cover by differencing the digital elevation models (DEMs) obtained from a snow-covered overflight and a snow-free overflight. Sixteen independent variables known to influence snow distribution are derived from a LiDAR digital elevation dataset, obtained during snow-free conditions, and used to predict snow distribution via binary regression trees. Variable ranges leading to the …

Megathrust Splay Fault Geometry In Prince William Sound, Alaska, Shaun Patrick Finn

Boise State University Theses and Dissertations

I present marine seismic reflection results from Prince William Sound, Alaska that document the location of active faults related to the subduction zone processes.

Subduction zones along convergent margins experience large earthquakes, magnitude >8, with recurrence intervals on the order of centuries. Smaller magnitude earthquakes with shorter recurrence intervals are probable along the same subduction zone fault zones. Convergent margin earthquakes also are associated with high uplift rates and tsunami generation, yet the location and uplift history of most tsunamigenic faults are unknown. In this thesis, I present the processed results of high resolution marine seismic reflection data of Prince …

Coupling Right- And Left-Handed Photons Differently To Charged Matter, Brett David Altschul

Faculty Publications

We consider a modification of electrodynamics in which right- and left-circularly polarized photons are coupled to charged sources differently. Even though photon helicity is a Lorentz invariant quantity, such a modification breaks Lorentz symmetry, as well as locality. The modified theory includes novel magnetic forces between perpendicular currents. Existing data can be used to constrain the modification at approximately a 2 x 10^(-3) level.

Restoration Of Biological Soil Crust On Disturbed Gypsiferous Soils In Lake Mead National Recreation Area, Eastern Mojave Desert, Lindsay P. Chiquoine

UNLV Theses, Dissertations, Professional Papers, and Capstones

Biological soil crusts (BSCs) are sensitive to anthropogenic disturbances. Natural recovery takes many years. Active restoration decreases recovery time. Native BSC inocula, which included lichens and mosses, salvaged from gypsiferous soil habitats in Lake Mead National Recreation Area (LMNRA) in the eastern Mojave Desert were stored dry for two years and applied to disturbed soil after a road reconstruction in LMNRA and also used in laboratory experiments to test inoculation technique effectiveness. After 18 months, field results revealed positive relationships between inoculation and the presence of macroscopic BSC cover, cyanobacteria abundance, soil stability, and ammonium concentrations. Chlorophyll fluorescence monitoring of …

A Gauge Theoretic Treatment Of Rovibrational Motion In Diatoms, Gregory Colarch

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Born-Oppenheimer approximation has long been the standard approach to solving the Schrödinger equation for diatomic molecules. In it, nuclear and electronic motions are separated into "slow" and "fast" degrees of freedom and couplings between the two are ignored. The neglect of non-adiabatic couplings leads to an incomplete description of diatomic motion, and in a more refined approach, non-adiabatic couplings are uncoupled by transforming the angular momentum of the molecule and electrons into the body-fixed frame.

In this thesis we examine a "modern" form of the Born-Oppenheimer approximation by exploiting a gauge theoretic approach in a description of molecular motion. …

Elemental Contributions From Minor And Major Constituents Of Bone On The Separation Of Radiostrontium, Ashlee Rae Dailey

UNLV Theses, Dissertations, Professional Papers, and Capstones

While many methods exist to separate and analyze radionuclides from a variety of environmental matrices, the performance of all of these methods is often limited by other interfering constituents that are consistently found in most of these samples. The presence of such constituents can significantly reduce the recovery of the radioisotopes of interests and lead to incomplete separations.

Strontium has the same oxidation state and a similar atomic radius as calcium and is therefore readily able to substitute for calcium in lattice sites. This similarity in behavior leads to the preferential accumulation of strontium in newly formed bone. The study …

An Estimate Of Groundwater Recharge In The Nabogo River Basin, Ghana Using Water Table Fluctuation Method And Chloride Mass Balance, Melanie Lynn Krautstrunk

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Cambrian-Precambrian fractured sandstone aquifer in the Nabogo River Basin in the Sahelian Northern Region in Ghana is one of the most important sources for fresh water supply for the local rural communities there. Recent population growth and commercial agricultural interests in this region could have an impact on this critical water resource. Groundwater recharge estimates are determined in this study using the Water Table Fluctuation Method and Chloride Mass Balance and can be applied to future sustainability studies of the region's water resources. Recharge estimates of the Water Table Fluctuation Method are in a range of 10-143 mm/yr or …

The Abundance And Distribution Pattern Of Quagga Mussels In The Las Vegas Bay Of Lake Mead, Nevada And Potential Correlation With Environmental Parameters, Scott Rainville

UNLV Theses, Dissertations, Professional Papers, and Capstones

The non-native quagga mussel [Dreissena bugensis (Andrusov, 1897)] was initially discovered in Boulder Basin of Lake Mead, Nevada-Arizona on January 6, 2007. This occurrence marked the first biological invasion of dreissenid mussels in the Western U.S., following a significant North American range expansion of invasive quagga mussels from populations that invaded and colonized the Great Lakes Region in the Northeastern U.S. during 1991. This nonindigenous mollusk species quickly spread from Boulder Basin and became established throughout the entire reservoir by the end of 2007, with the exception of the inner Las Vegas Bay. There was an apparent absence of settled …

Topics In Galaxy Formation: Pairwise Velocities Of Dark Matter Halos And Molecular Hydrogen Regulated Star Formation In Cosmological Simulations, Robert Jo Thompson

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this dissertation we investigate two distinct challenges within the concordance LCDM model and an unrelated project.

The first is a discrepancy between theory and observation. A massive galaxy sub-cluster known as the `bullet' has fallen through a more massive parent galaxy cluster at a redshift of z=0.296.

Theory finds that in order to reproduce the observational quantities of this cluster, an unusually high relative velocity of v12=3000 km/s between the two cluster's parent halos is required.

We quantify the statistical probability of producing a `bullet-like' halo pair within large N-body simulations, and

conclude that either the LCDM model is …

Integrated Approach For Hydrogeologic Investigations In Africa: Inferences From Space-Borne And Land-Based Gravity, Aeromagnetic, Gis, And Remote Sensing Data, Mohamed El Sayed Ahmed Ahmed

Dissertations

An integrated (space-borne and land-based gravity, aeromagnetic, GIS, and remote sensing) approach was developed, tested, and applied to investigate the following on regional scales (Africa) or local scales (El Qaa Plain, Sinai): (1) assess the capability of GRACE data (04/2002 to 08/2011) for monitoring elements of hydrologic systems on the sub-basin level (Task 1); (2) address the nature and the controlling factors (e.g., climatic and/or human pressure-related) affecting the inter-annual GRACE-derived Terrestrial Water Storage (TWS) trends over a large suite of hydrologic systems and domains in (Africa) (Task 2); and (3) identify the structural, geologic and hydrologic settings as well …

Generalizations Of Two Statistics On Linear Tilings, Toufik Mansour, Mark Shattuck

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, we study generalizations of two well-known statistics on linear square-and-domino tilings by considering only those dominos whose right half covers a multiple of 􀝇, where 􀝇 is a fixed positive integer. Using the method of generating functions, we derive explicit expressions for the joint distribution polynomials of the two statistics with the statistic that records the number of squares in a tiling. In this way, we obtain two families of q -generalizations of the Fibonacci polynomials. When 􀝇 􀵌 1, our formulas reduce to known results concerning previous statistics. Special attention is payed to the case 􀝇 …

Investigation Of Nonlinear Problems Of Heat Conduction In Tapered Cooling Fins Via Symbolic Programming, Hooman Fatoorehchi, Hossein Abolghasemi

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, symbolic programming is employed to handle a mathematical model representing conduction in heat dissipating fins with triangular profiles. As the first part of the analysis, the Modified Adomian Decomposition Method (MADM) is converted into a piece of computer code in MATLAB to seek solution for the mentioned problem with constant thermal conductivity (a linear problem). The results show that the proposed solution converges to the analytical solution rapidly. Afterwards, the code is extended to calculate Adomian polynomials and implemented to the similar, but more generalized, problem involving a power law dependence of thermal conductivity on temperature. The …

Planet Formation In Transition Disks: Modeling, Spectroscopy, And Theory, Joseph Liskowsky

All Dissertations

An important field of modern astronomy is the study of planets. Literally for millennia, careful observers of the night sky have tracked these 'wanderers', with their peculiar motions initiating avenues of inquiry not able to elucidated by a study of the stars alone: we have discovered that the planets (as well as Earth) orbit the sun and that the stars are so far away, even their relative positions do not seem to shift perceptibly when Earth's position moves hundreds of millions of miles. With the advent of the telescope, and subsequent improvements upon it over the course of centuries, accelerating …

The Update, December 2012, University Of Northern Iowa. College Of Humanities, Arts And Sciences.

Update

Inside this issue:
-- Having a Field Day: UNI Students Attend Geology Camp in Wyoming
--Contents December 2012
-- Department News
-- Art Students Present Research Papers at Midwest Humanities Conference
-- School of Music Events
-- Challenging Bullying Through Art
-- Alumni Spotlight: James Arns: Physics
-- UNI Forensics Team

The Effects Of Color Concentrates On The Rheology Of Tint Bases, Doug James Herrick

Master's Theses

ABSTRACT

THE EFFECTS OF COLOR CONCENTRATES ON THE RHEOLOGY OF TINT BASES

Douglas James Herrick

Waterborne coatings are formulated with a number of different ingredients; water, latex polymers, pigments, surfactants, dispersants, defoamers, biocides, coalescing aids, and rheology modifiers or thickeners. Rheology modifiers are necessary in order to improve the physical properties of the coating before, during, and after application to a substrate. There are two kinds of rheology modifiers used in waterborne coatings; associative thickeners and non-associative thickeners. Coatings formulated with associative thickeners are quite sensitive to coating variations; the slightest change in the formulation has profound effects on the …

Controlling Nanoparticle Dispersion For Nanoscopic Self-Assembly, Nathan S. Starkweather

Master's Theses

Nanotechnology is the manipulation of matter and devices on the nanometer scale. Below the critical dimension length of 100nm, materials begin to display vastly different properties than their macro- or micro- scale counterparts. The exotic properties of nanomaterials may trigger the start of a new technological revolution, similar to the electronics revolution of the late 20^th century. Current applications of nanotechnology primarily make use of nanoparticles in bulk, often being made into composites or mixtures. While these materials have fantastic properties, organization of nano and microstructures of nanoparticles may allow the development of novel devices with many unique properties. …

Effects Of Silvicultural Management On Coast Redwood Forest Composition, Density And Structure In Santa Cruz And San Mateo Counties, Michael J. Papa

Master's Theses

The multiple-objective exploratory study investigates effects of various silvicultural management regimes commonly applied to coast redwood (Sequoia sempervirens [D. Don] Endl.) forests in Santa Cruz and San Mateo Counties, California, USA. A temporary forest inventory was installed in 24 harvest origin stands and 4 natural origin stands throughout the study area (sample area = 1189 acres). Data from the systematic sample of 233 one-quarter acre nested cluster plots (sample intensity = 4.9%) rendered overall forest descriptions in terms of species composition, density, and structure. The common forestry measures of trees per acre (TPA), basal area per acre (BA), and …

On Numerical Solution For Optimal Allocation Of Investment Funds In Portfolio Selection Problem, Yahaya Abubakar

CBN Journal of Applied Statistics (JAS)

In this article, we present a procedure for obtaining an optimal solution to the Markowitz’s mean-variance portfolio selection problem based on the analytical solution developed in a previous research that lead to the emergence of an important model known as the Black Model. The procedure is well presented, illustrated and validated by a numerical example from real stocks dataset obtainable from a popular European stock market.

On The Development Of Residential Property Price Indices For Nigeria, Olowofeso E. Olorunsola, Abiodun S. Bada, Mohammed A. Bamanga

CBN Journal of Applied Statistics (JAS)

This work focuses on the development of house price indices for Nigeria, and the estimates of the Nigerian Residential Property Price Indices on housing characteristics are presented. Four main methods of index construction were considered, these are hedonic regression, repeat-sales, stratification and central price tendency methods. It was discovered that econometric methods like hedonic and repeat sales were constraints in constructing residential property price indices for Nigeria by the nature of the data available. Hence, the central price tendency and the sale-based stratification methods which are internationally used measures were applied to the available zonal-level dataset from a survey of …

Understanding The Dynamics Of Inflation Volatility In Nigeria: A Garch Perspective, Babatunde S. Omotosho, Sani I. Doguwa

CBN Journal of Applied Statistics (JAS)

The estimation of inflation volatility is important to Central Banks as it guides their policy initiatives for achieving and maintaining price stability. This paper employs three models from the Generalized Autoregressive Conditional Heteroscedasticity (GARCH) family with a view to providing a parsimonious approximation to the dynamics of Nigeria’s inflation volatility between 1996 and 2011. Of the competing models, the asymmetric TGARCH (1,1) provides an appropriate paradigm for explaining the dynamics of headline and core CPI volatilities in Nigeria, while the symmetric GARCH (1,1) was found to be adequate for food CPI. The results are quite revealing. Firstly, model outcomes indicate …

Radiative Double Electron Capture In Collisions Of Fully-Stripped Fluorine Ions With Thin Carbon Foils, Tamer Mohammad Samy Elkafrawy

Dissertations

Radiative double electron capture (RDEC) is a one-step process in ion-atom collisions occurring when two target electrons are captured to a bound state of the projectile simultaneously with the emission of a single photon. The emitted photon has approximately double the energy of the photon emitted due to radiative electron capture (REC), which occurs when a target electron is captured to a projectile bound state with simultaneous emission of a photon. REC and RDEC can be treated as timereversed photoionization (PI) and double photoionization (DPI), respectively, if loosely-bound target electrons are captured. This concept can be formulated with the principle …

Rule-Based Precise Localization Services In Mobile Environments, Mohammed Elbes

Dissertations

In recent years there has been great interest in the positioning of people and assets in indoor and outdoor environments. Many systems were constructed to accomplish this. The application of these systems depends on the environment and the precision required for localization. The Global Positioning System (GPS) cannot be used for a precise indoor localization due to the attenuation and scattering of the signals. For indoor environments, other technologies like Wireless LAN, laser, camera images and motion sensors are used in precise localization. GPS can be used in outdoor environments but if localization accuracy is a critical requirement, other technologies …

Boolean And Profinite Loops, Benjamin Andrew Phillips

Dissertations

A Quasigroup G consists of a set G together with a binary operation ∗ : G × G → G such that, for any elements a, b ∈ G there are unique solutions to the equations a ∗ x = b and y ∗ a = b within G. A loop is a quasigroup which also contains a 2-sided identity element. More heuristically, loops are essentially non-associative groups. However, without an associative binary operation, some of the familiar properties found in groups, such as 2-sided inverse, need not be present in loops.

The study of quasigroups and loops emerges …

K-Total Product Cordial Labelling Of Graphs, R. Ponraj, M. Sundaram, M. Sivakumar

Applications and Applied Mathematics: An International Journal (AAM)

In this paper we introduce the k-Total Product cordial labelling of graphs. Also we investigate the 3-Total Product cordial labelling behaviour of some standard graphs.

Geochemical Constraints On Groundwater Recharge In The Royal Slope Area, Grant County, Washington, Zoe Danielle Weis

All Master's Theses

Groundwater, the primary source for potable water in the Columbia Plateau, has experienced significant declines over the past 25 years. Groundwater geochemistry and multivariable statistics were employed to identify and characterize the hydrofacies present, constrain recharge sources, and assess mixing of groundwater in the Royal Slope area of the Columbia Plateau. Geochemical analyses for major ions, stable isotopes, and radiogenic isotopes (14C and tritium) for age dating were performed on groundwater samples collected in 2010 from 24 wells in the study area. The results confirmed that the groundwater evolution in the study area follows the typical Columbia River Basalt Group …

Reputation As Public Policy For Internet Security: A Field Study, Qian Tang, Leigh L. Linden, John S. Quarterman, Andrew Whinston

Research Collection School Of Computing and Information Systems

Cybersecurity is a national priority in this big data era. Because of the lack of incentives and the existence of negative externality, companies often underinvest in addressing security risks and accidents, despite government and industry recommendations. In the present article, we propose a method that utilizes reputation through information disclosure to motivate companies to behave pro-socially, improving their Internet security. Using outbound spam as a proxy for Internet security, we conducted a quasiexperimental field study for eight countries through SpamRankings.net. This outgoingspam-based study shows that information disclosure on outgoing spam can help reduce outgoing spam, approximately by 16 percent. This …

Do Hackers Seek Variety? An Empirical Analysis Of Website Defacements, Kok Wei Ooi, Seung-Hyun Kim, Qiu-Hong Wang, Kai Lung Hui

Research Collection School Of Computing and Information Systems

The importance of securing the cyberspace is higher than ever along with the evolution of cyber attacks launched by hackers with malicious intention. However, there has been little research to understand the hackers who are the most important agents determining the landscape of information security. This paper investigates the behaviors of hackers using a longitudinal dataset of defacement attacks. Based on theories of economics of criminal behaviors and variety seeking, we find that hackers seek variety in choosing their victims in terms of region, hacking method, and the type of operating systems; as their prior experience is focused in terms …

An Evaluation Of Fairness Among Heterogeneous Tcp Variants Over 10gbps High-Speed Networks, Lin Xue, Suman Kumary, Cheng Cui, Seung Jong Park

Computer Science Faculty Research & Creative Works

Several high-speed TCP variants are adopted by end users and therefore, heterogeneous congestion control has become the characteristic of newly emerging high-speed networks. In contrast to homogeneous TCP flows, fairness among heterogeneous TCP flows now depends on router parameters such as queue management scheme, buffer size, etc. To the best of our knowledge, this is the first evaluation of fairness among heterogeneous TCP variants over 10Gbps high-speed networks. Our evaluation scenarios for heterogeneous TCP flows consist of TCP variants with substantial presence in current Internet; therefore, TCP-SACK, CUBIC and HSTCP compete for bottleneck bandwidth. Experimental results for fairness are presented …

Search-Based Refactoring: Towards Semantics Preservation, Ali Ouni, Marouane Kessentini, Houari Sahraoui, Mohamed Salah Hamdi

Computer Science Faculty Research & Creative Works

Refactoring restructures a program to improve its structure without altering its behavior. However, it is challenging to preserve the domain semantics of a program when refactoring is decided/implemented automatically. Indeed, a program could be syntactically correct, have the right behavior, but model incorrectly the domain semantics. in this paper, we propose a multi-objective optimization approach to find the best sequence of refactorings that maximizes quality improvements (program structure) and minimizes semantic errors. to this end, we use the non-dominated sorting genetic algorithm (NSGA-II) to find the best compromise between these two conflicting objectives. We report the results of our experiments …