Physical Sciences and Mathematics Commons^™

Development Of A Web-Based Gis For Groundwater Exploration In Arid Lands, Nakul Manocha

Masters Theses

A three-fold exercise was conducted to assess the groundwater potentiality in the Eastern Desert (ED) of Egypt. First, a database was generated to host all relevant data sets in a GIS environment for a better understanding of the spatial relationships between these data sets. Co-registered digital mosaics were generated from relevant data sets including remote sensing (e.g., Landsat TM, SIR-C, SRTM, TRMM), geochemical (solute concentrations, O and H stable isotope composition), geological (geologic maps), and hydrological (lithology, depth to water table) data sets. Second, a web-based GIS interface (ArcIMS) was developed to provide a vehicle for data analysis, visualization, and …

Systems For Predicting Pitzer’S Ion-Interaction Model Parameters, Theresa Balderas Obias

Masters Theses

Pitzer's Ion-interaction Model had been widely used in predicting the non-ideal behavior of solution over a wide range of conditions for natural water systems. The model is successful only when there are sufficient parameters available. However, generating these needed parameters requires a great quantity of work and it would be advantageous to be able to predict the Pitzer's parameters for salt systems when there is no data available.

This research entailed the development of ionic radii dependent equations for Pitzer's binary ion-interaction parameters β_MX⁽⁰⁾, β_MX⁽¹⁾, β_MX⁽²⁾, and C^ϕ_MX . …

M4@Si28 (M=Al,Ga) Metal-Encapsulated Tetrahedral Silicon Fullerene, Yi Gao, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

It is known that silicon fullerenes cannot maintain perfect cage structures like carbon fullerenes. Previous density-functional theory calculations have shown that even with encapsulated species, nearly all endohedral silicon fullerenes exhibit highly puckered cage structures in comparison with their carbon counterparts. In this work, we present theoretical evidences that the tetrahedral fullerene cage Si₂₈ can be fully stabilized by encapsulating a tetrahedral metallic cluster (Al₄ or Ga₄). To our knowledge, this is the first predicted endohedral silicon fullerene that can retain perfectly the same cage structure (without puckering) as the carbon fullerene counterpart (T_{d …}

Chaotic Desynchronization Of Multistrain Diseases, Ira Schwartz, Leah Shaw, Derek Cummings, Lora Billings, Marie Mccrary, Donald Burke

Department of Mathematics Faculty Scholarship and Creative Works

Multistrain diseases are diseases that consist of several strains, or serotypes. The serotypes may interact by antibody-dependent enhancement rADE, in which infection with a single serotype is asymptomatic, but infection with a second serotype leads to serious illness accompanied by greater infectivity. It has been observed from serotype data of dengue hemorrhagic fever that outbreaks of the four serotypes occur asynchronously. Both autonomous and seasonally driven outbreaks were studied in a model containing ADE. For sufficiently small ADE, the number of infectives of each serotype synchronizes, with outbreaks occurring in phase. When the ADE increases past a threshold, the system …

A Note On The Orientation Of Symmetric Rigid Bodies Sedimenting In A Power-Law Fluid, Ashuwin Vaidya

Department of Mathematics Faculty Scholarship and Creative Works

We study the terminal orientation of symmetric bodies translating in a quiescent liquid modeled by the power-law fluid. We are able to show by invoking the symmetries of the sedimenting body and the Stokes flow field that at small Reynolds numbers, the competition of inertial and shear-thinning (or shear-thickening) contributions to the torque does not cause the tilt angle that is observed in experiments performed on viscoelastic liquids with shear-thinning properties.

Atr-Ftir Spectroscopic Analysis Of Sorption Of Aqueous Analytes Into Polymer Coatings Used With Guided Sh-Saw Sensors, Yolanda K. Jones, Zhonghui Li, Michael M. Johnson, Fabien Josse, Jeanne Hossenlopp

Chemistry Faculty Research and Publications

Attenuated total internal reflectance Fourier transform infrared (ATR-FTIR) spectroscopy was used for the investigation of sorption of aqueous solutions of analytes into polymer coatings. A series of simple model polymers, such as poly(dimethylsiloxane), poly(epichlorhydrin), and poly(isobutylene), and films and analytes, such as aqueous solutions of ethylbenzene, xylenes, toluene, and nitrobenzene, were used to evaluate the use of ATR-FTIR spectroscopy as a screening tool for sensor development. The ratios of integrated infrared absorption bands provided a simple and efficient method for predicting trends in partition coefficients. Responses of polymer-coated guided shear horizontal surface acoustic wave (SH-SAW) sensor platforms to the series …

Combined X-Ray Diffraction And Diffuse Reflectance Analysis Of Nanocrystalline Mixed Sn(Ii) And Sn(Iv) Oxide Powders, Hongmei Deng, Jeanne Hossenlopp

Chemistry Faculty Research and Publications

Nanocrystalline mixtures of Sn(II) and Sn(IV) oxide powders, potential gas sensor materials, are synthesized via a simple precipitation route using SnCl(2) as the precursor. Materials are characterized by powder X-ray diffraction, thermogravimetric analysis, UV-visible diffuse reflectance spectroscopy (DRS), and Fourier transform infrared spectroscopy. The ratio of Sn(II)/Sn(IV) in powders precipitated at room temperature, as well as the identity of the primary Sn(II) product (SnO or Sn(6)O(4)(OH)(4)), can be varied by adjusting aging time and washing procedures. The identity of the initial Sn(II) product influences the subsequent phase composition and degree of disorder in the tetragonal SnO(2) phase obtained following sintering …

A Combined Routing Method For Ad Hoc Wireless Networks, Zhenhui Jiang

Dartmouth College Master’s Theses

To make ad hoc wireless networks adaptive to different mobility and traffic patterns, we studied in this thesis an approach to swap from one protocol to another protocol dynamically, while routing continues. By the insertion of a new layer, we were able to make each node in the ad hoc wireless network notify each other about the protocol swap. To ensure that routing works efficiently after the protocol swap, we initialized the destination routing protocol's data structures and reused the previous routing information to build the new routing table. We also tested our approach under different network topologies and traffic …

Agro-Pastoralists’ Wrath For The Prosopis Tree: The Case Of The Il Chamus Of Baringo District, Kenya, D. Layne Coppock, Abdillahi A. Aboud, Phillip K. Kisoyan

Environment and Society Faculty Publications

Indigenous to Peru, Chile, and Argentina, the woody plant called Prosopis juliflora (also known by the American common name of “Honey Mesquite”) has spread world-wide in recent decades, including rangelands throughout Latin America, North America, south and central Asia, Australia, and sub-Saharan Africa. A species known for rapid establishment, high adaptability, and fast rates of growth, its dispersal has primarily been a consequence of intentional introduction by well- meaning “technical experts” who wanted to provide a new source of fodder, fuel wood, or a means to combat desertification in arid and semi-arid lands. One problem, however, is that unless Prosopis …

Linking Pastoralists And Exporters In A Livestock Marketing Chain: Recent Experiences From Ethiopia, D. Layne Coppock, Solomon Desta, Getachew Gebru, Seyoum Tezera

Environment and Society Faculty Publications

The Boran of southern Ethiopia have been traditionally viewed as unwilling or unable to engage in large scale, commercialized livestock trade. Here we report on the creation of a new livestock marketing chain from the Borana Plateau to export outlets largely serving the Gulf States. Since 2003 various meetings and exchange tours were organized by collaborating agencies and PARIMA to directly link pastoral producers with livestock exporters and policy makers. This occurred against a backdrop of growing export demand for small ruminants, rapid development of private export industry, formation of well-trained pastoral marketing groups (often dominated by women), and provision …

Using An Easy-To-Use And Free Tool In Teaching And Researching Networks And Security Issues, Victor A. Clincy

Faculty Articles

ITGuru is a powerful simulation environment developed by OpNET Corporation. ITGuru is unique because of its ability to model the entire networking domain, including its routers, switches, protocols, servers, and the individual applications they support. ITGuru improves network researchers' and instructors' ability to identify and solve problems throughout the network. The OpNET Corporation provides a FREE academic copy of their simulation environment to universities for both teaching and research.

Measuring The Evolution Of The Most Stable Optical Clock G 117-B15a, S. O. Kepler, Ted Von Hippel, Et Al.

Publications

We report our measurement of the rate of change of period with time () for the 215 s periodicity in the pulsating white dwarf G 117-B15A, the most stable optical clock known. After 31 years of observations, we have finally obtained a 4 σ measurement observed = (4.27 ± 0.80) × 10-15 s s-1. Taking into account the proper-motion effect of proper = (7.0 ± 2.0) × 10-16s s-1, we obtain a rate of change of period with time of = (3.57 ± 0.82) × 10-15 s s-1. This value is consistent with the cooling rate in our white dwarf …

Book Review: Stargazer: The Life And Times Of The Telescope, T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of Stargazer : the Life and Times of the Telescope by Fred Watson. Da Capo, 2004 342p, 0306814323 $24.95

The Application Of Category Theory And Analysis Of Receiver Operating Characteristics To Information Fusion, Steven N. Thorsen

Theses and Dissertations

Multisensor data fusion is presented in a rigorous mathematical format, with definitions consistent with the desires of the data fusion community. A model of event-state fusion is developed and described. Definitions of fusion rules and fusors are introduced, along with the functor categories of which they are objects. Defining fusors and competing fusion rules involves the use of an objective function of the researcher's choice. One such objective function, a functional on families of classification systems, and in particular, receiver operating characteristics (ROCs), is introduced. Its use as an objective function is demonstrated in that the argument that minimizes it …

Degree Of Sedentarization Affects Risks And Conflicts For The Waso Boran In Northern Kenya, D. Layne Coppock, Abdullahi D. Jillo, Mark N. Mutinda, Abdilla A. Aboud

Environment and Society Faculty Publications

The Waso Borana have lived for over a century in northern Kenya. In the last few decades, however, their ability to maintain their traditions has been severely challenged. Here we report survey results from 540 households in Isiolo District, stratified among three groups differing in terms of lifestyle: sedentary, semi-sedentary, and mobile. In some cases these groups vary with respect to important perceived risks, causes of natural-resource related conflict, and possible solutions to conflict. For example, sedentary respondents often noted concerns over land tenure problems, human diseases, and political incitement. Mobile respondents, in contrast, often noted primary concerns over drought, …

Paleoseismology Of The Black Hills Fault, Southern Nevada, And Implications For Regional Tectonics, Eric Fossett

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Black Hills fault (BHF) is a Holocene fault located in Eldorado Valley, approximately 7 km from Boulder City, southern Nevada. The importance of this study is to determine the seismic hazards the BHF poses to Boulder City and the greater Las Vegas metropolitan area and to determine the mechanisms driving the young deformation in the Lake Mead region. The BHF is a multistranded fault that had five surface rupturing paleoearthquake events in the past approximately 25 ka. Paleoseismic fault offsets indicate that the BHF is capable of generating a Mw = 6.4-6.9 earthquake. Slip rates calculated for the BHF …

Mutual Ionization In 200-Kev H⁻+ He Collisions, T. Ferger, Daniel Fischer, Michael Schulz, R. Moshammer, A. B. Voitkiv, B. Najjari, J. Ullrich

Physics Faculty Research & Creative Works

We studied mutual ionization in 200-keV H-⁺He collisions in a kinematically complete experiment by measuring the fully momentum-analyzed recoil ions and both active electrons in coincidence. Comparison of the data to our calculations, based on various theoretical models, show that mutual ionization proceeds predominantly through the interaction between both electrons. The post-collision interaction between the outgoing ejected electrons as well as higher order processes involving the interaction between the core of both collision partners are also important.

A Generic Object-Oriented Tabu Search Framework, Hoong Chuin Lau, Xiaomin Jia, Wee Chong Wan

Research Collection School Of Computing and Information Systems

Presently, most tabu search designers devise their applications without considering the potential of design and code reuse, which consequently prolong the development of subsequent applications. In this paper, we propose a software solution known as Tabu Search Framework (TSF), which is a generic C++ software framework for tabu search implementation. The framework excels in code recycling through the use of a well- designed set of generic abstract classes that clearly define their collaborative roles in the algorithm. Additionally, the framework incorporates a centralized process and control mechanism that enhances the search with intelligence. This results in a generic framework that …

On Sequential And Fixed Designs For Estimation With Comparisons And Applications, Mekki Terbeche, Broderick O. Oluyede, Ahmed Barbour

Mathematical Sciences: Faculty Publications

A fully sequential approach to the estimation of the difference of two population means for distributions belonging to the exponential family of distributions is adopted and compared with the best fixed design. Results on the lower bound for the Bayes risk due to estimation and expected cost are presented and shown to be of first order efficiency. Applications involving the Poisson and exponential distributions with gamma priors as well as the Bernoulli distribution with beta priors are given. Finally, some numerical results are presented.

Nonrelativistic Qed Approach To The Lamb Shift, Ulrich D. Jentschura, Andrzej Czarnecki, Krzysztof Pachucki

Physics Faculty Research & Creative Works

We calculate the one- and two-loop corrections of order α(Zα)⁶ and α²(Zα)⁶, respectively, to the Lamb shift in hydrogenlike systems using the formalism of nonrelativistic quantum electrodynamics. We obtain general results valid for all hydrogenic states with nonvanishing orbital angular momentum and for the normalized difference of S states. These results involve the expectation value of local effective operators and relativistic corrections to Bethe logarithms. The one-loop correction is in agreement with previous calculations for the particular cases of S, P, and D states. The two-loop correction in the order α²(Zα)⁶ includes …

Extreme Sensitivity Of Differential Momentum Transfer Cross Sections To Target Atom Initial Conditions, Ronald E. Olson, J. Fiol

Physics Faculty Research & Creative Works

Heavy-particle cross sections differential in the momentum transferred to the target are investigated using the classical trajectory Monte Carlo method. with the 3.6  MeV/u Au53++He system as a test case, it is shown that these cross sections are extremely sensitive to the initial target temperature. In particular, when thermal motion is varied for one of the target's initial momentum components between 0 and 25 K the absolute cross sections vary by orders of magnitude and, in addition, their relative shapes undergo major changes. We find that by setting one of the target's transverse momenta to a temperature of 16 K, …

Exafs Studies Of Bimetallic Ag-Pt And Ag-Pd Nanorods, Debdutta Lahiri, Soma Chattopadhyay, B. A. Bunker, Cm Doudna, Massimo F. Bertino, Frank D. Blum, Akira Tokuhiro, J. Terry

Physics Faculty Research & Creative Works

Nanoparticles of Ag-Pt and Ag-Pd with high aspect ratios were synthesized using a radiolysis method. Gamma rays at dose rates below 0.5 kGy/h were used for irradiation. the nanoparticles were characterized by transmission electron microscopy (TEM), optical absorption spectroscopy and x-ray Absorption Fine Structure (XAFS) spectroscopy. Bright field micrographs show that Ag-Pt nanowires are composed of large particles with diameters ranging from 20-30 nm and joined by filaments of diameter between 2-5 nm. the Ag-Pd nanowires have diameters of 20-25 nm and lengths of 1.5 μm. for XAFS measurements, the Pt L3 edge (11.564 keV), Ag K-edge (25.514 keV) and …

An Improvement And A Generalization Of Zippel's Sparse Multivariate Polynomial Interpolation Algorithm, Michael D. Brazier

Theses and Dissertations - UTB/UTPA

The algorithm most often used for the problem of interpolating sparse multivariate polynomials from their values is Zippel's probabilistic algorithm (1988). The algorithm evaluates the function to be interpolated at a significant number of points, and for many problems of interest processing evaluations dominates the running time. This thesis presents an improvement of Zippel's algorithm, which decreases the number of evaluations needed for an interpolation by using transposed Vandermonde systems for the univariate interpolation step of Zippel's algorithm. The technique also allows a more general form of the algorithm: it becomes possible to interpolate more than one variable within a …

Pervasive Cracking Of The Northern Chilean Coastal Cordillera: New Evidence For Forearc Extension, John P. Loveless, Gregory D. Hoke, Richard W. Allmendinger, Gabriel González, Bryan L. Isacks, Daniel A. Carrizo

Geosciences: Faculty Publications

Despite convergence across the strongly coupled seismogenic interface between the South American and Nazca plates, the dominant neotectonic signature in the forearc of northern Chile is arc-normal extension. We have used 1 m resolution IKONOS satellite imagery to map nearly 37,000 cracks over an area of 500 km2 near the Salar Grande (21°S). These features, which are best preserved in a ubiquitous gypcrete surface layer, have both nontectonic and tectonic origins. However, their strong preferred orientation perpendicular to the plate convergence vector suggests that the majority owe their formation to approximate east-west extension associated with plate boundary processes such as …

Studying The Performance Of A Firewall In Network Courses, José M. Garrido

Faculty Articles

This paper presents a simple simulation model of a firewall to derive several performance metrics and briefly argues on the importance and value of modeling and simulation in courses that study various aspects of perimeter defense in network security.

The simulation model mentioned previously is part of an effort by faculty of our department to develop a multi-disciplinary repository of computational models that includes object-oriented discrete-event simulation models. One of the goals of this repository is to build resources that help educate students of computer science, software engineering, and information technology, in modeling and information security.

This and other network …

J2me Programming, Chong-Wei Xu

Faculty Articles

Handheld devices, such as programmable cell phones and personal digital assistants (PDAs), have already become more numerous than PCs. Students need to be prepared today to work on the most widely available computing platforms of tomorrow. With their small size and mobility, these handheld devices present both new opportunities and unique software engineering challenges. J2ME stands for Java 2 Micro Edition that is one of the three Java Editions (J2SE, J2EE, and J2ME) specially designed for handheld devices. J2ME plus handheld devices are the platforms for wireless Internet and mobile business in the future.

A Steerable, Untethered, 250x60 Micron Mems Mobile Micro-Robot, Bruce R. Donald, Christopher G. Levey, Craig D. Mcgray, Igor Paprotny, Daniela Rus

Computer Science Technical Reports

We present a steerable, electrostatic, untethered, MEMS micro-robot, with dimensions of 60 µm by 250 µm by 10 µm. This micro-robot is 1 to 2 orders of magnitude smaller in size than previous micro-robotic systems. The device consists of a curved, cantilevered steering arm, mounted on an untethered scratch drive actuator. These two components are fabricated monolithically from the same sheet of conductive polysilicon, and receive a common power and control signal through a capacitive coupling with an underlying electrical grid. All locations on the grid receive the same power and control signal, so that the devices can be operated …

Assessing The Relationships Between The Spatial Variation In Land-Use Spatial Patterns And Surface Water Quality, Majed A. Khater

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this dissertation was to examine the association between the spatial patterns of urban land uses and surface water quality parameters at the watershed outlet. The aim of the study was to understand the strength and nature of this relationship, and examine new methods of classifying and quantifying contributing urban land-uses and their spatial patterns. The hypothesis of this research was: in an urban watershed, the variation in the spatial patterns of contributing land uses will have a significant impact on the surface water quality parameters at the watershed outlet.

This relationship between urbanization and water quality is …

Galactic Cosmic-Ray Modulation Using A Solar Minimum Mhd Heliosphere: A Stochastic Particle Approach, Bryan M. Ball, Ming Zhang, Hamid K. Rassoul, Timur J. Linde

Aerospace, Physics, and Space Science Faculty Publications

An example of Galactic cosmic-ray modulation in a fully three-dimensional heliosphere is presented here. We use a stochastic particle method to solve for modulation without requiring symmetric boundaries or fields. We include all typical modulation terms, including full three-dimensional drift. We have applied this to an MHD heliosphere appropriate for solar minimum conditions. This field includes nonradial solar wind velocity components, as well as a built-in nonspherical termination shock. Parameters that are of interest in modulation can be analyzed in detail, particularly the momentum change of cosmic rays during their transport through the heliosphere. We show radial profiles of modulation …

Ecotoxicology And Environmental Education In The Development Of A Turtle Conservation Program In Southeastern Tennessee, Stefan L. Moss

Masters Theses and Doctoral Dissertations

In 1999, the Tennessee Aquarium initiated a long-term mark-recapture study to promote the conservation of freshwater turtles in the Tennessee River Gorge (TRG). The TRG consists of a 42-kilometer stretch of the Tennessee River surrounded by 27,000 acres (11,000 hectares) and is known as the "Grand Canyon of Tennessee." In 2002, the Aquarium established a partnership with The University of Tennessee at Chattanooga (UTC) and the Tennessee River Gorge Trust (TRGT) to expand the program. Since then, researchers at UTC have been conducting scientific research at the TRG each year in an effort to increase the amount of available information …