Physical Sciences and Mathematics Commons^™

Visualization And Animation Of A Missile/Target Encounter, Jeffrey T. Bush

Theses and Dissertations

Existing missile/target encounter modeling and simulation systems focus on improving probability of kill models. Little research has been done to visualize these encounters. These systems can be made more useful to the engineers by incorporating current computer graphics technology for visualizing and animating the encounter. Our research has been to develop a graphical simulation package for visualizing both endgame and full fly-out encounters. Endgame visualization includes showing the interaction of a missile, its fuze cone proximity sensors, and its target during the final fraction of a second of the missile/target encounter. Additionally, this system displays dynamic effects such as the …

A Modeling Study For The Implementation Of In Situ Cometabolic Bioremediation Of Trichloroethylene-Contaminated Groundwater, John A. Christ

Theses and Dissertations

The limitations of conventional groundwater remediation technologies have led to the development of innovative technologies which may achieve national hazardous waste site remediation goals. Before an innovative technology can be implemented in the field, remedial project managers, regulators and other stakeholders require adequate modeling tools to help assess the applicability of the technology at a particular site. This modeling study investigates how an innovative technology, in situ cometabolic bioremediation, might be implemented to remediate a TCE-contaminated site, under different site conditions. A steady-state model is developed which couples an analytical expression to simulate the effect of flow between multiple pumping …

Reduced Computational Cost, Totally Symmetric Angular Quadrature Sets For Discrete Ordinates Radiation Transport, Joseph M. Oder

Theses and Dissertations

Several new quadrature sets for use in the discrete ordinates method of solving the Boltzmann neutral particle transport equation are derived. These symmetric quadratures extend the traditional symmetric quadratures by allowing ordinates perpendicular to one or two of the coordinate axes. Comparable accuracy with fewer required ordinates is obtained. Quadratures up to seventh order are presented. The validity and efficiency of the quadratures is then tested and compared with the Sn level symmetric quadratures relative to a Monte Carlo benchmark solution. The criteria for comparison include current through the surface, scalar flux at the surface, volume average scalar flux, and …

Vertical Axis Rotation In The Silurian Hills: A Cenozoic Overprint On The Mesozoic U.S. Cordilleran Magmatic Arc, John E. Comstock

University of New Orleans Theses and Dissertations

New, detailed field work in the Silurian hills, southeast of Death Valley, reveals a pattern of a complex Cenozoic brittle fault overprint of rocks containing evidence of at least three episodes of Mesozoic thermal-ductile deformation. The Cenozoic brittle fault overprint of rocks containing evidence of at least three episodes of Mesozoic thermal-ductile formation. The Cenozoic faulting consists of five distinct sets of structures ordered by cross cutting relationships. The oldest, BF1, are fragments of reverse faults trending NW and dipping 45-60 SW. BF2 consist of NW trending, en echelon, sinistral strike-slip faults. BF3 is a conjugate set of N-NE trending …

The Migration Of Arsenic And Lead In Surface Sediments At Three Kids Mine Henderson, Nevada, Douglas Brian Sims

Publications (WR)

This study focused on the distribution of arsenic and lead in surface sediments at Three Kids Mine in Henderson, Nevada. The mine site encompasses approximately 470 acres of desert and is situated above two developing communities (Lake Las Vegas and Calico Ridge) and the Las Vegas Valley's water source (Lake Mead).

Transport of arsenic and lead appears to have occurred within a limited range in both the eastern and western washes on the eastern and western sides of Three Kids Mine. Concentrations of arsenic range between 20 mg/kg (ppm) and 1130 mg/kg and between 20 mg/kg and 8400 mg/kg for …

Unfolding Of The Period-Two Bifurcation In A Fiber Laser Pumped With Two Modulation Tones, Scott Glasgow, T. C. Newell, A. Gavrielides, V. Kovanis, D. Sukow, T. Erneux

Faculty Publications

The effect of a small second frequency component on a pump modulated neodymium fiber laser is investigated experimentally and theoretically. This term, whose frequency is exactly half the primary driver, incites an unfolding of the attractor. It breaks the period two pitchfork bifurcation and splits the period one orbit. The modification of the bifurcation diagram is studied analytically by employing a map derived from the class B laser rate equations. We determine specific conditions and scaling laws for this phenomenon. Our analytical predictions are in good agreement with recorded experimental data.

Inhibitory Effect Of Carbamate On The Cell Division Of Rat Bone Marrow, Mariam Hamad Rashed Al-Dhaheri

Theses

The cytotoxic effect of methomyl carbamate was studied in three groups (control group, 1 % treated group and 10% treated group) and each group contain 2-3 White Wistar rats. The 1% treated group was received 1 % of methomyl LD₅₀, while the 10% treated group was received 10% of methomyl LD₅₀. The administration was orally and repeated three times with 24 hr intervals time. The effect of methomyl was investigated in four experimental run, by analysing the change in cell count in bone marrow after methomyl treatment. It was found that methomyl treatment caused significant reduction …

Pesticide-Related Health Problems And Illness In Farm-Workers In The United Arab Emirates, Mahra Mohammed Mahmood Beshwari

Theses

Arabian Gulf countries, witnessed rapid development in many aspects of life. Although these

developments have improved the quality of life in the UAE, they have drawbacks that generated

health problems and environmental hazards. One of the consequences of rapid development is the

usage of large amounts of pesticides in agricultural production for the sake of increasing the yield of crops. However, the expanded use of these pesticides is known to result in acute respiratory symptoms and changes in body metabolism. To-date, no population-based study has been conducted to investigate the effects of pesticides on plasma amino acids and liver enzyme …

Application Of Geophysical And Geochemical Techniques For The Assessment Of Groundwater Recharge From Wadi Al Bih Dams, Ras Al Khaimah, United Arab Emirates, Mohamed Sager Al Asam

Theses

Groundwater from Wadi AI Bih is still a major source of water required for irrigation, industry and domestic purposes in Ras AI Khaimah area, United Arab Emirates. Because of the continuous population growth, demand for pumping more water has created an imbalance in the groundwater resources of Wadi AI Bih basin, and the estimated discharge (11 million m³/year) has exceeded the calculated natural recharge (9 million m³/yr). To restore the balance between natural recharge and discharge and maintain a good-quality groundwater, the UAE government has built Wadi AI Bih dams in 1982.

The objectives of this …

Structure In Zero-Divisor Graphs Of Commutative Rings, Philip S. Livingston

Masters Theses

In this research, we associate a graph in a natural way with the zero-divisors of a commutative ring. We endeavor to characterize various attributes of the graph, including connectivity, diameter, and symmetry. In exploring symmetry in the graph, we examine the automorphism group of the graph, and provide a complete characterization for the rings Z_N. Secondly, we seek ring-theoretic properties which may be described in terms of the associated zero-divisor graph. These include, among other results, a strong relationship between finite local rings and graphs admitting a vertex connected to every other vertex.

Continuation Of Illinois River Water Quality Monitoring Of Moores Creek, Paul F. Vendrell

Technical Reports

In Northwest Arkansas, nutrients transported by surface water are a major concern. These nutrients are implicated in causing water quality impairment of lakes in Northwest Arkansas and eastern Oklahoma. The nutrients of concern are nitrogen and phosphorus. Nitrogen and phosphorus stimulate algae production in water bodies and can cause objectionable water quality. Problems associated with algae growth are aesthetic impairment, objectionable taste and odor of potable water, interference with recreation activities, and fish kills in some hyper-eutrophic cases. The sources of these nutrients are primarily from land application of confined animal wastes as soil amendments to pastures. In 1990, the …

Studies On Resolution Of Enantiomeric Dialkylaryl Sulfonium Ions With Nmr Shift Reagents, Ea-Ji-Ru Son

Masters Theses & Specialist Projects

Praseodymium(III) NMR shift reagent, which is an upfield shift reagent, is focused on for assessment of enantiomeric excess and resolution of methyl sulfonium ions. A series of alkylmethylphenylsulfonium ions were analyzed, where alkyl is ethyl (I), butyl(H), octyl (III), and benzyl(IY). The praseodymium agent gives base-lined resolution of the ortho hydrogens resonance for I and IH. All spectra are strongly temperature-dependent. I is shifted more than ED, consistent with a steric effect. Assignments for I were made by gradually increasing the concentration of the shift reagent and by analyzing R-enriched I. Racemization of R-enriched isomer of I by pyramidal inversion …

Temperature-Dependence Studies Of Photorefractive Effect In A Low Glass-Transition-Temperature Polymer Composite, Bogdan Swedek, Ning Cheng, Yiping Cui, Jaroslaw W. Zieba, Jeffrey G. Winiarz, Paras N. Prasad

Chemistry Faculty Research & Creative Works

The temperature dependence of the photorefractive effect in a polymer composite containing poly(9-vinycarbazole), tricresyl phosphate, buckminsterfullerene, and 4-(N,N-diethylamino)-β-nitrostyrene is presented. The photoconductive, electro-optic and photorefractive properties of the material have been studied in the temperature range of 22-61°C. An apparent increase of electro-optic modulation with temperature and its eventual saturation is observed. This behavior is attributed to the temperature activated orientational mobility of the second-order nonlinear chromophores. The polarization anisotropy between the p- and s-polarized readouts is consistent with what would be expected on the basis of directly measured effective electro-optic coefficients. By correlating the electro-optic value with the diffraction …

Modeling Uptake And Translocation Of Lead (Pb) In Maize For The Purposes Of Phytoextraction, Mark A. Brennan

Theses and Dissertations

Phytoextraction is a remediation technology that uses plants to remove heavy metals from soil. This technology has the potential to decrease the costs of remediating contaminated sites by several orders of magnitude compared to traditional technologies. To effectively implement this technology requires an understanding of the plant processes that control uptake and translocation of metals from the soil. Currently these processes are poorly understood, and especially so for Pb. The purpose of this thesis was to gain insights concerning the plant mechanisms that control uptake and translocation of Pb and how these mechanisms interact to control levels of Pb accumulation …

Collision Spectroscopy Of Low Energy Capture By Multiply Charged Ions From Atomic Targets, Kadir Akgungor

Dissertations

State-selective differential cross sections for single-electron capture processes in very slow collisions of Ar^q+ (q = 4 - 6) ions with Ne, and Ar^6+ ions with He have been studied experimentally at laboratory collision energies between 15 and 100 qeV, and at scattering angles between 0° and 8° by means of translational energy-gain spectroscopy technique. The translational energy spectra show that only a few final states are populated depending on the charge state of the projectile, the projectile laboratory scattering angle, and the collision energy. These measurements also show that the dominant reaction channels are due to capture into excited …

The Rational Resolution Analysis: A Generalization Of Multi-Resolution Analyses With Application To To The Specific Emitter Identification Problem, Bruce P. Anderson

Theses and Dissertations

The rational resolution analysis RRA is introduced and developed as a generalization of the integer, dilation multiresolution analyses MRA developed by Mallat and Meyer. Rational dilation factors are achieved by relaxing the condition on MRAs that successive approximation spaces be embedded. Conditions for perfect reconstruction are discussed and it is shown that perfect reconstruction is possible with specific constraints on the scaling function the scaling filter must have its roots on the unit circle. Furthermore, the required arrangement of the roots indicate the scaling function must be derived from a B-spline of some degree. It is proven the only compactly …

Layout For Visualizing Large Software Structures In 3d, Colin Ware, Glenn Franck, Monica Parkhi, Tim Dudley

Center for Coastal and Ocean Mapping

There is increasing evidence that 3D visualization of complex structures has advantages over 2D visualization. While nested directed graphs are an important method of representing information in 2D or 3D, they must be effectively organized in order to be understood. Most work on graph layout has assumed that fully automatic layout is desirable. Through our work with graphs representing large software structures, we have found that, due to the importance of the semantic content, it is necessary to combine automatic layout with manual layout. This paper describes a system called GraphVisualizer3D, which was designed to help people understand large nested …

Microelectromechanical Optical Beam Steering Systems, David M. Burns

Theses and Dissertations

The development of microelectromechanical systems (MEMS) has matured to the point where the fabrication of micron sized devices is feasible. State of the art MEMS construction processes now support the fabrication of novel optical devices that could not previously be built. This dissertation reports on the development of innovative micro optical devices such as Variable Blaze Gratings (VBGs) using state of the art MEMS construction processes. The principle application of the micro optical devices described in this dissertation is steering optical beams; however other applications such as spectral analysis are identified. Specific optical beam steering systems developed and characterized in …

The Fate And Transport Of Airborne Jp-4 And Jp-8 Aerosol During Cold Startup, Bradford Eugene Buckman

Theses and Dissertations

During cold startup (engine warm-up) procedures at northern tier bases, fuel aerosol (JP-4 and JP-8) is emitted before complete combustion of the fuel occurs. The time necessary for complete combustion to occur may be as long as 10 minutes. Hence, during these first few minutes, aerosol is emitted at relatively high concentrations. This research investigates the principle behavior of the emitted aerosol: advection, dispersion, evaporation, and settling. Using previous work in fuel jettisoning and evaporation as a foundation, this thesis investigates the physical factors affecting the airborne concentration of fuel aerosol at different times, the amount of fuel aerosol reaching …

Collisional Broadening Of Spectral Lines In The X → B System Of O2 And The First Vibrational Band Of No By The Noble Gases, John J. Cornicelli

Theses and Dissertations

Collisional broadening of the rotational spectral lines of the X to b system of O₂ and the first vibrational band of NO by the noble gases is examined by Fourier transform spectroscopy. Peaks of the individual rotational lines are modeled with a Voigt function, from which Lorentzian half widths are extracted. Lorentzian widths are plotted vs. pressure of foreign gas, from which the pressure broadening coefficients and pressure broadening cross sections are calculated. The pressure broadening coefficients are compared to theoretical values determined by past research for O₂. NO coefficients are compared to similar research using N …

Time Resolved Photoluminescence Spectra Of A Mid-Infrared Multiple Quantum Well Semiconductor Laser, Anthony L. Franz

Theses and Dissertations

Recombination mechanisms in mid-IR semiconductor lasers are strongly dependent on the carrier density of the active region. The objective of this research is to improve previous carrier density estimates through the incorporation of spectral information. One hundred photoluminescence (PL) spectra were calculated for a variety of carrier densities. Calculations were made for an InAsSb/InAlAsSb multiple quantum well laser sample assuming parabolic bands. The widths of the calculated spectral profiles were tabulated as a function of carrier density. Actual spectra were measured using the Ultrafast Mid-Infrared Photoluminescence System, which uses upconversion to measure the PL intensity in time steps smaller than …

A Modeling And Simulation Approach To Characterize Network Layer Internet Survivability, Leif S. King

Theses and Dissertations

The Air Force Core Competency of Information Superiority will be achieved in an age of decreasing AF manpower and corporate expertise. Increased AF reliance on COTS solutions, coupled with nearly ubiquitous points of entry to communication networks, create unique challenges in maintaining the Information Superiority edge. The protection of the internet is part of this equation. The internet supports the daily business traffic of the Air Force. Personnel, finance, and supply data flow through its routers. Controlling an adversary's access to our information systems, either the data, or the hardware and software that control the data and transform it into …

Architecture, Design, And Implementation Of A Rapidly Prototyped Virtual Environment For A Military Spaceplane, Scott A. Rothermel

Theses and Dissertations

The new Global Engagement vision places increased emphasis on the Air Force's ability to control and exploit space. A military spaceplane combining reliable access to space, high operational tempos, and multi-mission capabilities is in conceptual stages of development. Virtual environment technology provides an opportunity to investigate system requirements and unconventional interface paradigms for this unique vehicle. A virtual environment architecture and design based on support for a rapid prototyping development process, separation of concerns, and user interface development is presented. The rapid prototyping process allowed management of changing requirements via an evolutionary approach to implementation. Separation of the activities performed …

The Century Survey: A Deeper Slice Of The Universe, Margaret J. Geller, Michael J. Kurtz, Gary Wegner, John R. Thorstensen

Dartmouth Scholarship

The "Century Survey" (CS hereafter) is a complete redshift survey of a 1° wide strip. It covers 0.03 steradians to a limiting m_R = 16.13. The survey is 98.4% complete and contains 1762 galaxies. Large-scale features in the survey are qualitatively similar to those in other surveys: there are large voids surrounded or nearly surrounded by thin dense regions which are sections of structures like (and including) the Great Wall. The survey crosses the classical Corona Borealis supercluster. The galaxy density enhancement associated with this system extends for <˜100h^-1 Mpc^-1 (the Hubble constant is H₀ = 100h …

An Analytical Method To Calculate Activity From Measurements Affected By Coincidence Summing, Anthony P. Popovich

Theses and Dissertations

An analytical method is developed and applied to find the activities of two radioisotopes based on measurements influenced by true coincidence summing. The method incorporates the solid angle subtended by the detector, the macroscopic cross sections of the materials present, the absolute peak and total efficiencies of the detector, and the modes and probabilities of decay of the radioisotope. With this information, the method corrects for both summing-in and summing-out events. Summing events affect peak counts and cause the calculated activity to differ from the true activity. Thin disk sources of Mo-99 and Cs-136 on the face of a closed-end, …

A Plan For Characterizing Waste For The Defense Special Weapons Agency At The Nevada Test Site, Tiffany A. Hatcher

UNLV Theses, Dissertations, Professional Papers, and Capstones

In 1976, Congress adopted the Resource Conservation and Recovery Act (RCRA) to govern hazardous waste. The Act was amended in 1984 with the Hazardous and Solid Waste Amendments in order to further define the requirements of RCRA. RCRA is meant to protect human health and the environment from the effects of hazardous waste, promote waste minimization, and encourage material recycling and recovery. For this purpose, regulations are implemented that cover every aspect of the hazardous waste problem, including generation, transport, treatment, storage, and disposal.

Generators of waste are the most important part of this chain. As defined in RCRA, a …

Public Participation Program Development: An Analysis Of Public Participation In The Water Industry, Marcia Lynne Holmberg

UNLV Theses, Dissertations, Professional Papers, and Capstones

The field of public participation is a distinct, but yet unpolished facet within the public relations industry. While the purpose of and need for public participation are becoming increasingly clear, many remain unaware or unconvinced of its advantages. Likewise, even among those who endorse the necessity of public participation, its methods and strategies continue to be a mystery to most.

One industry, in particular, that has recognized and embraced the benefits of conducting public participation is the water utility industry. The purpose of this thesis is to 1) crystallize the understanding of why public participation is a necessary and advantageous …

Breast Cancer Mass Detection Using Difference Of Gaussians And Pulse Coupled Neural Networks, Donald A. Cournoyer

Theses and Dissertations

CAD, serving as a second reader, has been shown to improve the success of radiologists at detecting breast cancer. This thesis will develop a new algorithm to identify masses in mammograms. The system developed for this thesis will be capable of assisting a radiologist in making decisions.

A Representational Approach To Knowledge And Multiple Skill Levels For Broad Classes Of Computer Generated Forces, Larry J. Hutson

Theses and Dissertations

Current computer generated forces (CGFs) in the 'synthetic battlespace', a training arena used by the military, exhibit several deficiencies. Human actors within the battlespace rapidly identify these CGFs and defeat them using unrealistic and potentially fatal tactics, reducing the overall effectiveness of this training arena. Simulators attached to the synthetic battlespace host local threat systems, leading to training inconsistencies when different simulators display the same threat at different levels of fidelity. Finally, current CGFs are engineered 'from the ground up', often without exploiting commonalities with other existing CGFs, increasing development (and ultimately training) costs. This thesis addresses these issues by …

A Single Chip Low Power Implementation Of An Asynchronous Fft Algorithm For Space Applications, Bruce W. Hunt

Theses and Dissertations

A fully asynchronous fixed point FFT processor is introduced for low power space applications. The architecture is based on an algorithm developed by Suter and Stevens specifically for a low power implementation. The novelty of this architecture lies in its high localization of components and pipelining with no need to share a global memory. High throughput is attained using large numbers of small, local components working in parallel. A derivation of the algorithm from the discrete Fourier transform is presented followed by a discussion of circuit design parameters specifically, those relevant to space applications. The generic architecture is explained with …