Digital Commons Network^™

Spectral Analysis Of The Flow Behavior Of Big Spring, Kings Canyon National Park, California, Linda Urzendowski

UNLV Theses, Dissertations, Professional Papers, and Capstones

Big Spring, the resurgence of a karst aquifer in the Lilburn Cave system (Kings Canyon National Park, California), displays the uncommon phenomena of ebb and flow discharge during periods of high runoff.

Hydrograph analyses indicate that the portion of Lilburn Cave between the Z-Room and Big Spring is primarily a conduit flow aquifer. The power spectra strongly indicate a nonlinear system, with evidence of quasi-linear behavior found on a smaller scale. The transfer and kernel function indicate that no additional significant inputs or outputs to the system exist. The bench-scale model built to simulate the ebb and flow cycles in …

The Geology Of The Tuff Of Bridge Spring: Southern Nevada And Northwestern Arizona, Shirley Ann Morikawa

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Tuff of Bridge Spring (TBS) is a regionally-widespread, andesite to rhyolite (59.50 to 74.91 wt. %) ash-flow tuff of mid-Miocene age (ca. 15.2 Ma) that is exposed in the northern Colorado River extensional corridor of southern Nevada and northwestern Arizona. Determination of the areal distribution, geochronology, lithology, geochemistry, and internal stratigraphy of the TBS is important for its establishment as a reliable stratigraphic reference horizon for tectonic reconstructions of the extensional corridor during the middle Miocene. Based on reoccurring patterns of major and trace element variation, the TBS is divided into constant Cr/variable SiO₂ and variable Cr/variable SiO …

The Multifile Opac Environment: A Manageable Approach To Developing An Instruction Program, Jeanne M. Brown

Library Faculty Publications

The article offers advice on developing an instruction program in the multifile online public access catalog (OPAC) environment in a systematic manageable way. Several areas that emerged as basic to an instruction program for multifile OPAC include selection criteria for various databases and search concept relevant across databases. It cites some reasons behind the need for remote database searching including finding citations to materials not at the home library. It suggests approaches for initial exploration of a system.

Unlv Magazine, Barbara Cloud

UNLV Magazine

No abstract provided.

Analysis And Evaluation Of The Workplace Exposure Assessment Workbook Developed By Keith Tait Including Some Recommended Revisions, Lisa Hebberd

UNLV Theses, Dissertations, Professional Papers, and Capstones

Some risk due to the contamination of workplace environments is an inevitable part of human lives. These risks can often be reduced by improving the control of environmental pollution in the workplace. An extremely important challenge for any industry is to develop a mechanism to identify acceptable levels of safety, or "acceptable risk" in the workplace for specific situations, and to assure adequate quality control over measured or calculated exposure concentrations and their possible contributions to adverse health effects.

Observation Of Non-Isotropic Auger Angular Distribution In The C(1s) Shape Resonance Of Co, Oliver Hemmers, Franz Heiser, J. Eiben, R. Wehlitz, U. Becker

Environmental Studies Faculty Publications

Angle-resolved high-resolution C(KVV) Auger spectra of CO were taken in the vicinity of the C(1s) σ^* shape resonance. These spectra show clear evidence for the theoretically predicted anisotropic K-shell Auger emission in molecules. Complementary results from angle-resolved photoion spectroscopy show that the small size of the observed effect is, besides the varying intrinsic anisotropy of the Auger decay, also due to a smaller anisotropy in the primary absorption process than originally predicted but in good agreement with more recent calculations. Contrary to this, satellite Auger transitions show unexpectedly large anisotropies.

Optimization Of The Seating Position In A Human-Powered Vehicle, Y. Lei, Mohamed Trabia, D. Too

Mechanical Engineering Faculty Research

Until recently, most of the human-powered vehicles (HPV) were designed focusing solely on its aerodynamics characteristic. In many of these HPV designs, the rider seating position was arbitrarily chosen without consideration of its effect on the rider's comfort and cycling effectiveness. Also, there is no guarantee that the seating position is related to maximum power output. Too (1991) used an experimental approach to determine that the rider will produce the maximum anaerobic power when the seat tube angle of a bicycle is at 75° whereas Hull and Gonzalez (1990) used an engineering approach to optimize the cycling biomechanics. However several …

Internet Resources For Architecture Studies, Jeanne M. Brown

Library Faculty Publications

There are many means of finding one's way around the Internet. Gopher, Veronica, and WAIS are just some of the search mechanisms currently in place. For the beginner, however, the Internet can be overwhelming in the wealth of its resources and in the multiplicity of its organization.

Unlv Magazine, Barbara Cloud, Lisa Story

UNLV Magazine

No abstract provided.

War Crimes Of The 90s: Rape As A Strategy, Mary Guinan

Public Health Faculty Publications

Historically, only men went to war. The winners took the losers' women and could rape, enslave, or kill them. As we moved into a more modern civilization, the rights of the winner over the women of the loser became less clear and were only vaguely documented. Even for modern war historians, what happens to the men on and off the battlefield is the main preoccupation. After all, women do not face combat and what happens to them seems unimportant. The rape of women by conquering armies has continued through all wars, but has rarely been considered a war crime, especially …

Multiplet-Changing Auger Transitions In Valence Double Photoionization, U. Becker, Oliver Hemmers, B. Langer, I. Lee, A. Menzel, R. Wehlitz, M. Ya Amusia

Environmental Studies Faculty Publications

The decay of valence satellite states in neon above the first double-ionization threshold has been studied experimentally and theoretically. Special emphasis was given to differentiate between two decay modes: valence Auger and valence-multiplet Auger decay. It is shown that the latter process is predominant in the low kinetic energy part of the spectrum. The main structures of this low-energy Auger spectrum could be designated by help of calculated transition energies and decay rates.

Evaluation Of Rutting Resistance Of Coarse Graded Aggregate Asphaltic Concrete Mixes In Clark County, Nevada, Jerold Dewayne Stegeman

UNLV Retrospective Theses & Dissertations

The purpose of this study is to evaluate the effectiveness of utilizing coarse aggregates in asphaltic concrete pavements for reducing rutting in Clark County, Nevada. Previous specifications used for asphaltic concrete mix designs in the Clark County area allowed for a wide range of aggregate gradations. The aggregate gradations in the asphaltic concrete mixes produced from these specifications tended to be on the finer side of the range. The pavements constructed based on the specifications were observed to be tender and susceptible to rutting. Paving projects were initiated which demonstrated that coarser aggregates in the asphalt mixes appeared to reduce …

Analysis And Evaluation Of Three Promising Nuclear Waste Disposal Options, Venugopal Veeramachaneni

UNLV Retrospective Theses & Dissertations

Disposal of high level nuclear waste has evoked much interest among scientists, engineers and society at large. Numerous schemes have been proposed in this regard and a few have been analyzed thoroughly. However, these schemes have been found to be valid only under very specific environmental conditions, thus imposing constraints on the scheme of disposal. The option of retrievability imposed another constraint. In addition to accommodating the constraints, the disposal scheme must also comply with federal regulations (NRC 10 CFR PART 60, EPA 10 CFR PART 191, DOE 10 CFR PART 960). Due to the longevity of radionuclide toxicity, the …

A Comparative Study Between Gaming And Non-Gaming Food And Beverage Operations Using Management By Values As An Analytical Tool, Cheryl Christine Baker

UNLV Retrospective Theses & Dissertations

This thesis analyzes gaming and non-gaming hotel restaurants to determine whether there is a need to reevaluate food and beverage operations in gaming hotel restaurants due to the changing trends in the economy and changing consumer demands; Management by Values is used as an analytical tool to determine if gaming hotel restaurants should follow the trend non-gaming hotel operations have established and reorganize their food and beverage operations. A questionnaire followed by a personal interview was used to gather information and Management by Values is used to evaluate the information; The final results proved that gaming operations do not need …

Evaluation Of Selected Aliphatic Acids And Polytetrahydrofurans For Use As Calibration Agents For Thermospray Hplc/Ms, Tonya Rose Dombrowski

UNLV Retrospective Theses & Dissertations

A method of tuning and calibration for a thermospray ion source on a benchtop quadrupole mass spectrometer using trifluoroacetic acid, pentafluoropropionic acid, heptafluorobutyric acid, polytetrahydrofuran-250, and polytetrahydrofuran-650 was proposed and evaluated. A 0.5% solution of the aliphatic acids showed good mass range coverage (163-641) in the negative mode, and no substantial memory effects. This mixture was evaluated over 45 days for fluctuations in the ion intensities and ratios. It remained stable within the expected thermospray reproducibility range, although the volatility of the trifluoroacetic acid made daily preparation of standard mixtures necessary. A similar solution of the polytetrahydrofurans was evaluated in …

Self-Stabilizing Deadlock Algorithms In Distributed Systems, Mitchell Elliott Flatebo

UNLV Retrospective Theses & Dissertations

A self-stabilizing system is a network of processors, which, when started from an arbitrary (and possibly illegal) initial state, always returns to a legal state in a finite number of steps. Self-stabilization is an evolving paradigm in fault-tolerant computing. This research will be the first time self-stabilization is used in the areas of deadlock detection and prevention. Traditional deadlock detection algorithms have a process initiate a probe. If that probe travels around the system and is received by the initiator, there is a cycle in the system, and deadlock is detected. In order to prevent deadlocks, algorithms usually rank nodes …

Harmonic Analysis Of Transformer Excitation Currents, Xiaoqiang Gong

UNLV Retrospective Theses & Dissertations

Transformer core nonlinearity has been a subject of research in electrical power engineering for many decades. An accurate and simple transformer model that takes into account its iron saturation appears to be lacKing The objective of this thesis is to propose a voltage-dependent model of transformer core nonlinearity that predicts the exciting current waveforms at various supply voltages. The model is composed of the core loss resistance and magnetizing reactance as seen by the fundamental frequency component and a series of parallel-connected harmonic current phasors. The single-phase transformer model is extended to represent three-phase transformers under various connections, including Y/Y, …

Exchange Of Oxygen And Hydrogen Isotopes Between Water And Water Vapor: Experimental Results, Michael Willem Slattery

UNLV Retrospective Theses & Dissertations

The exchange of {dollar}\delta\sp{18}{dollar}O, {dollar}\delta{dollar}D, and tritium between water and water vapor was quantified using two methods. The first was quiescent equilibration of water samples having widely contrasting isotopic compositions, surface areas, volumes and temperatures, but similar salinities. Rates of exchange (k) depended on surface area and vapor pressure, while the end-point equilibrium was controlled by volume and isotopic composition of the exchanging waters. Values of k ranged from 0.09 to 0.19 cm/day at 22{dollar}\sp\circ{dollar}C and from 0.86 to 0.92 cm/day at 52{dollar}\sp\circ{dollar}C. The second method involved sparging 30 l of tritiated water (5,000 and 630,000 TU) with a constant …

Application Of Multirate Digital Signal Processing To Image Compression, Ali Akrouf

UNLV Retrospective Theses & Dissertations

With the increasing emphasis on digital communication and digital processing of images and video, image compression is drawing considerable interest as a means of reducing computer storage and communication channels bandwidth requirements. This thesis presents a method for the compression of grayscale images which is based on the multirate digital signal processing system. The input image spectrum is decomposed into octave wide subbands by critically resampling and filtering the image using separable FIR digital filters. These filters are chosen to satisfy the perfect reconstruction requirement. Simulation results on rectangularly sampled images (including a text image) are presented. Then, the algorithm …

Character Recognition And Information Retrieval, Julia Ann Cooley Borsack

UNLV Retrospective Theses & Dissertations

Presented are two technologies, character recognition and information retrieval, that are used for text processing. Character recognition translates text image data to a computer-coded format; information retrieval stores these data and provides efficient access to the text. The necessity of their eventual coupling is obvious. Their sequential application though (with no manual intervention) has been considered impractical at best. Our experimentation exploits these two technologies in just this way. We identify problems with their combined use, as well as show that the technologies have come to a point where they can be applied in succession.

Members' Perception Of Service Quality At The Nellis Air Force Base Officers' Open Mess, Brian Douglas Campbell

UNLV Retrospective Theses & Dissertations

This study pertains to members' perceptions of service quality at the Nellis Air Force base Officers' Open Mess. The Officers' club members were surveyed using the parsimonious 22-item SERVQUAL instrument. Perceptions were compared to expectations to achieve a SERVQUAL score for the five dimensions of service quality. These scores were then averaged to obtain an Overall Unweighted and Weighted SERVQUAL score for the Officers' Club. The results indicated that the Officers' Club was providing less than average service quality as perceived by the club members. The Active Duty members perceived the difference to be greater than that of the Other …

On The Effect Of Dynamic Adjustment Of Recurrent Network Parameters On Learning, Stephen Lee Felgar

UNLV Retrospective Theses & Dissertations

The thesis examines sequential learning in a neural network model derived by M. I. Jordan and J. L. Elman. In each of three experiments, different network parameters are systematically altered in a series of simulations. Each simulation measures learning ability for a specific network configuration. Simulation results are consolidated to summarize each parameter's significance in the learning process.

Dynamic Analysis Of An Overhead Crane Carrying A Canister By Finite Element Method, Vijayachander Reddy Musukula

UNLV Retrospective Theses & Dissertations

A finite element model for an overhead crane carrying a nuclear waste canister is developed. This model is used to perform the static, dynamic and impact analysis using the finite element software COSMOS/M. Static results are compared with simplified model solutions to verify the accuracy of the finite element model. Frequency analysis is also performed to determine the first six natural frequencies of the system. Three of these six frequencies are compared with analytical results for verification. In the dynamic analysis, the crane is allowed to travel for a specified time. A computer program is written to connect static and …

Distributed Mutual Exclusion Algorithms, Paul Banta

UNLV Retrospective Theses & Dissertations

In this thesis we present three original algorithms which solve the distributed mutual exclusion problem. Two of the three solve the problem of allowing only one site at a time into the critical section. The third solves the more difficult problem of allowing a specific number of sites (k sites) into the critical section at a time; All three algorithms are "Token Based". That is, they make use of a token and token queue in order to guarantee mutual exclusion. Only the site that currently has the token is allowed to enter its critical section in the 1 mutual exclusion …

Evaluation Of Filter Pack Dewatering On Voc Concentrations In A Simulated Low-Yield Monitoring Well, Gary Allen Icopini

UNLV Retrospective Theses & Dissertations

A physical model was constructed to investigate the physical process of dewatering the filter-pack of a low-yield ground-water monitoring well and determine if this process effects the concentration of dissolved volatile organic compounds (VOCs). It was hypothesized that losses of VOCs would be observed as a result of an increased air-water interface and possibly turbulent flow through the filter pack during water-level recovery; Little or no measurable losses of 1,1,1-TCA, MCB, or 1,1,2,2-TET were detected during water-level recovery while simulating non-stagnant well conditions. These data imply that losses of VOCs due to volatilization resulting from the physical action of water …

Social Support And The Woman With Breast Cancer: Issues Of Measurement, Bonnie Margaret Ivey

UNLV Retrospective Theses & Dissertations

The ability of the nurse to accurately and consistently measure the social support variable is invaluable to assessing the client's well being. This methodological study, based on Neuman's holistic view of the client, proposed to substantiate the reliability and validity of the PRQ85 as a measure of perceived social support with women experiencing breast cancer; A sample of 82 women with breast cancer responded to a composite questionnaire consisting of two social support measures (Personal Resource Questionnaire (PRQ85)), Norbeck Social Support Questionnaire (NSSQ)), two instruments to measure the mental health constructs depression (Beck Depression Inventory (BDI)) and anxiety (Spielberger Trait …

A Comparison Of The Comprehension Of Procedural Information Using Computer And Hard-Copy Media, Aiessa Moyna Lawrence

UNLV Retrospective Theses & Dissertations

Users of technical procedures must be able to understand the documents to use them to perform their work. As more companies contemplate putting their procedures on-line, it is important to know whether computer systems will be as effective as traditional hard-copy presentation in communicating procedures to the employees who must use them; To determine whether there is a relationship between computer usage and the comprehension of technical procedures, an experiment was conducted among employees of a scientific and technical company in Las Vegas, Nevada. A control group read and demonstrated its comprehension of hard-copy procedures only, while an experimental group …

A Genetic Algorithm Applied To The Fractal Inverse Problem, Hiroo Miyamoto

UNLV Retrospective Theses & Dissertations

The theory of iterated function systems (IFS) allows one to construct a fractal which depends on a finite number of parameters. The associated inverse problem, finding a set of parameters which reconstructs a given fractal, is much more difficult. This paper explores the possibility of solving the inverse program with the genetic algorithm.

Effects Of Soil Moisture, Soil Carbonate And Organic Matter Content On Vapor Phase Sorption Of Volatile Organic Compounds Using Inverse Gas Chromatography, John Stephen Schmeltzer

UNLV Retrospective Theses & Dissertations

Sorption of VOCs from the vapor phase to soils is an important variable in predicting VOC contaminant movement in unsaturated soils. Experiments were performed which evaluated the effects of soil moisture, carbonate, and organic matter content on VOC sorption. Sorption measurements were performed for ten VOC compounds: trichloroethylene (TCE); 1,1,1-trichloroethane (TCA); benzene; toluene; ethylbenzene; chlorobenzene; heptane; and pentane. Inverse Gas Chromatography (IGC) was the primary method used to measure VOC sorption in these experiments. Sorption for all the evaluated VOCs decreased with increasing moisture. Non-reversibility in the water characteristic curve of water had significant implications for the sorption of VOCs …

The Effect Of Surface Treatment And Rolling Direction On The Fatigue Behavior Of Grade One Commercially Pure Titanium, Shilong Tang

UNLV Retrospective Theses & Dissertations

Fully-reversed bending fatigue tests were conducted on both the as-received and finished grade one commercially pure titanium. Finishing is done by a process developed by TiMesh Inc., and known as TiMesh finishing. Results show that TiMesh finishing can not only increase material fatigue life at least by two times at the stress level of 25 Ksi, but also eliminate the anisotropic fatigue behavior observed in the as-received materials.