Digital Commons Network^™

Modelling Land Subsidence Due To Groundwater Pumping/Recharging In The Las Vegas Valley, Mehmet Necmi Okuyan

UNLV Retrospective Theses & Dissertations

A model for ground settlement and swelling occurring in Las Vegas Spring Preserve due to groundwater level changes has been developed. A FORTRAN code that uses the finite element method has been prepared. The computer code calculates the hydraulic head in the aquifer resulting from pumping and recharging of the Wells The settlement or swelling of the ground level at each node point is calculated based on hydraulic conditions. The computed hydraulic head and settlement resulted between January 1990 and December 1999 have been compared to the observed static heads and the measured settlement; The sensitivity of the settlement to …

Development Of A Gis-Based Framework For Evaluating Space And Parking Utilization, Jyothi S Tallapragada

UNLV Retrospective Theses & Dissertations

Large organizations such as corporations and universities typically occupy many buildings. A typical university space includes classrooms, laboratories, offices, and parKing The cost of adding additional space is significant. Therefore, effective management and utilization of the space is critical, especially to organizations that are growing. Growth may be measured in terms of the number of employees or students. As the number of employees and students increase, the number of trips to the campus also increase. This poses a growing pressure on the parking supply at the campus; The main objective of this thesis is to develop a framework for evaluating …

A Web-Based Finite Element Model For Heat Transfer, Trevor Allen Wilcox

UNLV Retrospective Theses & Dissertations

A web based Java program has been developed to solve 2-D transient or steady state heat transfer problems. The numerical solver is based on the finite element method. The program is designed to work with both triangle and quadrilateral elements. In this thesis the development of the finite element method, using the Galerkin weighted residuals method, is reviewed and the technique applied to the advection-diffusion equation for the transport of temperature. The Java code and graphical interface used to implement the solver for use on the Internet is discussed.

Systemic Environmental Analysis Of The Legal Mechanisms For Controlling Air Pollution In The Las Vegas Valley, Richard Little

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study examines the air pollution control structure for the Las Vegas Valley. A System Dynamics computer model was created that represents the structure of the real world system for controlling air pollution, in order to examine how the current air pollution control system might behave in the future.

Mineral Paragenesis And Ore Fluids At The Turquoise Ridge Gold Deposit, Nevada, Michiko Shigehiro

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this study, mineral assemblages and related fluid inclusions at the Turquoise Ridge Carlin-type gold deposit were examined to answer the following questions: (1) What is the ore-stage mineral paragenesis? (2) At what pressures and temperatures did the deposits form? (3) What are the sources of ore fluids?

Pyrite with gold, jasperoid quartz, stibnite, orpiment, realgar, and calcite were successively deposited at Turquoise Ridge. Microthermometric data and isotopic ratios of inclusion fluids in ore-related minerals indicate entrapment of multiple generations of fluids in pre-ore, ore-, and late-ore stage minerals. Primary fluid inclusions in an ore-stage jasperoid quartz crystal have salinities …

Comparison Of One-Dimensional And Two-Dimensional Hydrodynamic Modeling Approaches For Red River Basin, Sajjad Ahmad, Slobodan P. Simonovic

Civil and Environmental Engineering and Construction Faculty Research

EXECUTIVE SUMMARY

A devastating flood in Red River valley in 1997 emphasized the need to study the flood control measures in the Red River basin using state of the art modeling tools. The Red River and its floodplains can be modeled using one-dimensional, quasi two-dimensional or fully two-dimensional hydrodynamic models. Each modeling approach has its own advantages and limitations. The main purpose of this report is a comparison between one-dimensional (or quasi two dimensional) and fully two-dimensional hydrodynamic modeling approaches for modeling floods in the Red River basin.

A two-dimensional hydrodynamic model, MIKE 21, coupled with Geographic Information System (GIS) …

Alteration Associated With Gold Deposition At The Getchell, Carlin-Type Gold Deposit, North-Central Nevada, Tracy Lynn Cail

UNLV Theses, Dissertations, Professional Papers, and Capstones

Alteration at the Getchell deposit was examined to determine the effects of ore-bearing fluids on host lithologies and the relationship between K-bearing alteration minerals and Au deposition. The geochemistry of unaltered to highly altered and mineralized rocks from the Getchell deposit was quantified for 54 samples collected along 14 transects in calcareous siltstone, carbonaceous limestone, and a rhyodacitic dike. Each transect was collected along a single homogeneous bed that could be followed from visibly unaltered waste rock into high-grade ore.

Calculated elemental gains and losses record an increase in the concentrations of Au, Hg, Sb, Se, Si, Te, Tl, and …

Reciprocal Transplantation Of The Desert Soil Crust: Can It Be Done?, Christina D. Cole

UNLV Theses, Dissertations, Professional Papers, and Capstones

A 100 meter X 100 meter study site was chosen at White Rock Springs in Red Rock Canyon National Conservation Area, Nevada. To examine Syntrichia caninervis, a desert crustal moss, reciprocal transplantations (20 mm and 40 mm diameter cores) were performed between shaded to shaded, exposed to exposed, and shaded to exposed microsites to determine if it was possible to transplant the study organism with reasonable survivorship. Transplants were inspected following rain events for percent hydration, number of dead stems, and change in percent cover. Data indicated that there was a low mortality rate of S. caninervis stems, and few …

A Comparison Of Public Agency And Casino Employee Turnover Rates In Las Vegas, Timothy A. Clemens

UNLV Theses, Dissertations, Professional Papers, and Capstones

The primary focus of this professional paper is to determine and then compare turnover rates between public agencies and the gaming industry in the Las Vegas area. The paper's intention is to discover what differences and similarities in employee turnover rates exist between public agencies and casinos. A secondary focus is to determine if the public sector can provide any lessons to lower employee turnover to the Las Vegas gaming industry. This secondary focus is based on the assumption that public agencies have higher employee retention (and, therefore, a lower rate of turnover) than those found within the Las Vegas …

What Is Y2k And How Did The University Of Nevada System Solve It?, Diane R. Dietrich

UNLV Theses, Dissertations, Professional Papers, and Capstones

The turn of the century change from 1999 to 2000 will create chaos for the world's computer systems. This paper will discuss the causes of the Y2K problem, the reaction to this problem by the University of Nevada System Computer Services and possible repercussions of this problem for Nevada, the United States and the world.

Validity Of The Independent-Particle Approximation In X-Ray Photoemission: The Exception, Not The Rule, D. Hansen, Oliver Hemmers, H. Wang, Dennis W. Lindle, P. Focke, I. A. Sellin, Clemens Heske, H. S. Chakraborty, P. C. Deshmukh, S. T. Manson

Environmental Studies Faculty Publications

A combined experimental and theoretical study of argon valence photoionization illustrates the discovery of the broad lack of validity of the independent-particle approximation (IPA) for x-ray photoemission. In addition to previously known breakdowns of the IPA, which are limited to high photon energies and regions very near threshold, the observed breakdown in photoionization at intermediate energies demonstrates generally that the IPA is valid only in very restricted domains. These restrictions are expected to be relevant throughout the periodic table, with consequences for a wide variety of applications.

Evolutionary Patterns Of Morphometrics, Allozymes And Mitochondrial Dna In Thrashers (Genus Toxostoma), Robert M. Zink, Donna L. Dittmann, John Klicka, Rachelle C. Blackwell-Rago

Ornithology Program (HRC)

We examined patterns of variation in skeletal morphometrics (29 characters), allozymes (34 loci), mitochondrial DNA (mtDNA) restriction sites (n = 74) and fragments (n = 395), and mtDNA sequences (1,739 bp from cytochrome b, ND2, ND6, and the control region) among all species of Toxostoma. The phenetic pattern of variation in skeletal morphometrics generally matched traditional taxonomic groupings (based on plumage patterns) with the exceptions of T. redivivum, which because of its large size clusters outside of its proper evolutionary group (lecontei), and T. occelatum, which did not cluster with T. curvirostre. Skull characters contributed highly to species discrimination, suggesting …

Unlv Residence Hall Recycling & Reuse Program For Move-In And Move-Out, Angela Michelson

UNLV Theses, Dissertations, Professional Papers, and Capstones

The goal of this thesis was to develop a program for the UNLV Residence Hall Recycling & Reuse Program for Move-In and Move-Out that would collect unwanted and unneeded materials from the residents and put them to use. Move-In collected cardboard boxes for recycling while Move-Out collected usable items such as shoes, clothes, food, bedding, and school supplies for resale. In order to have a good collection turnout, a combination of advertising and resident and staff education was conducted. Letters were sent to Resident Assistants (RA’s) and Complex Coordinators and posters and other advertisements were placed in high traffic areas …

Geochemistry And Petrogenesis Of The Bonanza King Mafic Intrusive Complex, Trinity Terrane Ophiolite, California, Keith R. Willse

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Bonanza King mafic intrusive complex (MIC) (>25 km^2₎ of the Trinity terrane ophiolite, northern California, consists of cogenetic plutonic and dike lithologies. Steep intrusive contacts exist between cumulate pyroxenite, isotropic gabbro, and peridotite country rock. Near vertical east-west trending, bimodal dikes intruded gabbro and are centered within the complex. Geochemical modeling indicates taht accumulation/fractionation of a gabbroic parental magma produced lithologic trends of cumulate pyroxenite and fractionated gabbro and dike lithologies. Similarities between all lithologies suggest cogenetic formation of all the elements of the Bonanza King MIC during the Late Silurian (431 +/- 3).

Parental magma …

The Origin Of Brucite In Hydrothermally Altered Limestone Near Devil Peak, Nevada, Rhonda L. Knupp

UNLV Theses, Dissertations, Professional Papers, and Capstones

Open-space brucite was identified in veins crosscutting hydrothermally altered limestone near the Devil Peak rhyolite plug in southern Nevada. The brucite occurs with serpentine, calcite, chalcedony, hydromagnesite, dolomite, and clinochlore.

Brucite usually forms as a replacement mineral, but textural evidence indicates that the brucite at Devil Peak precipitated in open space. The presence of chalcedony in veins indicates the temperature of the hydrothermal fluid was <180^oC during and after mineral deposition. Thermodynamic modeling shows this temperature is too low for replacement brucite to form, thus the low temperature of alteration may be a factor in this unusual occurrence of …

Low-Temperature Molecular Beam Epitaxy Of Gaas: A Theoretical Investigation Of Antisite Incorporation And Reflection High-Energy Diffraction Oscillations, K. Natarajan, Rama Venkat, Donald L. Dorsey

Electrical & Computer Engineering Faculty Research

Surface dynamics dominate the incorporation of charged, As+Ga, and neutral, As0Ga, antisite arsenic, and the temporal variation of reflection high-energy electron diffraction(RHEED) intensity in the low-temperature molecular beam epitaxy of (100) gallium arsenide(GaAs). A rate equation model is proposed which includes the presence and dynamics of a physisorbed arsenic (PA) layer riding the growth surface. The PA layer dictates the incorporation and concentration of As+Ga and As0Ga. Additionally, it influences the RHEED oscillations (ROs) behavior and the RO’s dependence on its coverage through its contribution to the reflected intensity. The model results for the dependence of As+Ga and As0Ga concentrations …

The Geochronology And Geochemistry Of The Bearhead Rhyolite, Jemez Volcanic Field, New Mexico, Leigh Justet

UNLV Theses, Dissertations, Professional Papers, and Capstones

Around 82% of mapped Bearhead Rhyolite (Main Cluster) and Peralta Tuff appears to have been derived from a relatively long-lived (~680 ka), large, shallow (Earth's surface) magma chamber that did not produce a caldera-forming eruption. Although volatile contents were great enough (~ wt.% H₂O), no large-scale explosive eruptions occurred because magma may have been tectonically vented. The lack of systematic chemical variation within the Main Cluster with time during this ~680 ka interval may imply that erupted magmas were physically separated from each other by fault-formed cupolas in the roof of the magma chamber. These results are significant …

Golf Courses In Southern Nevada Will Significantly Impact The Water Management Efforts By Using Recycled Water Rather Than Potable Water To Irrigate Their Turf, Sean D. Ainsworth

UNLV Theses, Dissertations, Professional Papers, and Capstones

As the number of people continually move to the Las Vegas Valley and take up residence, the possibility of "running out of water" can become a reality. Having large water users (i.e. golf courses) irrigate their turf with recycled water, they will significantly impact the water management efforts in the Las Vegas Valley. When each course is irrigating their turf with recycled water, this will help ease the drinking water demand in the valley, especially during the peak demand season (summer).

Rio Natural Gas, The Alternative Fuel Of The Future, Peter Garner

UNLV Theses, Dissertations, Professional Papers, and Capstones

Automobile exhaust is a major contributor of harmful air pollutants. Exhaust emissions include water (H2O), carbon dioxide (CO2), carbon monoxide (CO), nitrous oxides (NOX), sulfur oxides (SOX), hydrocarbons (HC), and particulate matter (PM), and of these the four major air pollutants are CO, HC, NOX, and PM. Particulate matter is predominantly emitted from diesel fuel burning vehicles. In order to aid in reduction of air pollution, and reduce dependence on foreign oil imports, federal legislation has been enacted. The two prominent acts are the National Energy Security Act in 1992, which mandates use of alternative fuels, and the Clean Air …

Sliding Mode Measurement Feedback Control For Antilock Braking Systems, Cem Unsal, Pushkin Kachroo

Electrical & Computer Engineering Faculty Research

We describe a nonlinear observer-based design for control of vehicle traction that is important in providing safety and obtaining desired longitudinal vehicle motion. First, a robust sliding mode controller is designed to maintain the wheel slip at any given value. Simulations show that longitudinal traction controller is capable of controlling the vehicle with parameter deviations and disturbances. The direct state feedback is then replaced with nonlinear observers to estimate the vehicle velocity from the output of the system (i.e., wheel velocity). The nonlinear model of the system is shown locally observable. The effects and drawbacks of the extended Kalman filters …

Source Water Assessment Plan, Water Quality Division

Publications (WR)

The safe drinking water amendments of 1996 placed a strong emphasis on the goal to establish a nationwide effort to protect drinking water sources. As part of that goal, the legislation provided for a preliminary assessment of drinking water sources and an inventory of surrounding adjacent land use (ALUs). This nationwide effort will result in the first comprehensive look at the nation's drinking water sources from an assessment perspective. One of the outcomes of this nationwide assessment will be information that public water systems (PWSs) can use to help determine appropriate monitoring frequencies and to protect their sources of drinking …

Arizona Source Water Assessment Plan Final Draft, Arizona Department Of Environmental Quality

Publications (WR)

The safe drinking water amendments of 1996 placed a strong emphasis on the goal to establish a nationwide effort to protect drinking water sources. As part of that goal, the legislation provided for a preliminary assessment of drinking water sources and an inventory of surrounding adjacent land use (ALUs). This nationwide effort will result in the first comprehensive look at the nation's drinking water sources from an assessment perspective. One of the outcomes of this nationwide assessment will be information that public water systems (PWSs) can use to help determine appropriate monitoring frequencies and to protect their sources of drinking …

Strategic Planning For Hotel -Casino Projects, Franklin Neil Baker

UNLV Retrospective Theses & Dissertations

Hotel-casinos have exhibited financial trouble and failure rates which exceed 30%. Even so, billions of dollars have been earmarked for continual development within the industry. The purpose of this study was to examine classical theories of strategic decision-making when planning for new or expanded hotel-casinos and then determine if these theories work for the industry or if the industry is so unique that special measures must become part of the strategic-planning process; Three factors related to strategic planning were selected for study: economic indicators, the product/service life cycle, the Altman Z Factor for bankruptcy prediction. Twelve Chief Financial Officers representing …

Response Of Tall Fescue To Saline Water As Influenced By Leaching Fractions And Irrigation Uniformity Distributions, Algirdas M Leskys

UNLV Retrospective Theses & Dissertations

Research was conducted to determine the impact leaching fractions (LF = drainage volume divided by irrigation volume) and irrigation uniformity distributions have on the response of tall fescue to irrigation with saline water. Tall fescue (Festuca arundinacea Schreb. 'Monarch') was grown in 18 plots, each with a centrally located lysimeter that enabled estimates of evapotranspiration and irrigation requirements. Imposed treatments included setting LFs at 0.05, 0.15, or 0.25 and manipulating plot irrigation systems such that Christiansen Uniformity Coefficients (CUC) were set at 0.65, 0.75, or 0.85. Saline irrigation water (2.5 dS m{dollar}\sp{-1}{dollar}) was applied for an 18-month period. Significant LF …

Reply To Comment On ‘Nondipole Resonant X-Ray-Raman Spectroscopy: Polarized Inelastic Scattering At The K Edge Of Cl2,’, J. D. Mills, J. A. Sheehy, T. A. Ferrett, S. H. Southworth, R. Mayer, Dennis W. Lindle, P. W. Langhoff

Chemistry and Biochemistry Faculty Research

Mills et al. Reply: In their Comment on our Letter [1], Gel’mukhanov and Ågren [2] reiterate recent assertions [3] based on their earlier theoretical studies [4]. The primary purpose of their Comment is apparently to refute our stated conclusion that core-excited-state localization/ delocalization mechanisms are irrelevant to interpretations of reported Raman scattering experiments on homonuclear diatomic molecules.

Real-Time Digital Speech Transmission Over The Internet, Angelos Angelopoulos

UNLV Retrospective Theses & Dissertations

This thesis describes a complete system for real-time digital speech communication over the Internet. A digital speech compressor is described, and a new real-time Internet protocol is designed. We focus on the mathematical representation of the system as well as its implementation providing pseudo-code routines for all components and algorithms. Our contribution stands in a combined solution to the problem that removes undesired properties, such as speech clipping and delay, that appeared in Internet real-time communication systems implemented in the past.

The Optimal Room Inventory Of Las Vegas Casino Hotels, Ming Chen

UNLV Retrospective Theses & Dissertations

Room oversupply is a recent concern for Las Vegas gaming industry. The purpose of this research is to quantify this problem and try to determine whether room oversupply exists and if it does, how serious the problem is in the lodging market of Las Vegas casino hotels (the subject market). A room inventory model is developed for estimating the optimal room inventory of the subject market. The real room inventory of the past nine fiscal years and the planned room inventory of the next two fiscal years are compared with the optimal room inventory. The research finds that the room …

What Does Smart Growth Mean For Housing?, Karen A. Danielsen, Robert E. Lang, William Fulton

Public Policy and Leadership Faculty Research

Barely noticed amid the returns from the 1998 midterm elections was a quiet revolution that goes to the heart of how and where Americans live. While most news accounts focused on the high-profile candidate elections, voters across the nation-in Democratic and Republican areas alike-approved more than 160 state and local ballot measures intended to preserve open space and limit urban sprawl.

The coalition forming around the idea of limiting sprawl includes environmentalists, farmers, big-city mayors, and some developers. But perhaps most important, the so-called "smart growth" movement also includes many suburban voters who are fed up with growth. For example, …

H∞ Tracking Control For A Class Of Nonlinear Systems, Joseph A. Ball, Pushkin Kachroo, A. J. Krener

Electrical & Computer Engineering Faculty Research

Develops the theory for tracking control using the nonlinear H∞ control design methodology for a class of nonlinear input affine systems. The authors use a two-step process of first designing the feedforward part of the controller to design for perfect trajectory following and then design the feedback part of the controller using nonlinear H∞ regulator theory. Results for infinite-time and finite-time horizons are presented

Multiple Stochastic Learning Automata For Vehicle Path Control In An Automated Highway System, Cem Unsal, Pushkin Kachroo, John S. Bay

Electrical & Computer Engineering Faculty Research

This paper suggests an intelligent controller for an automated vehicle planning its own trajectory based on sensor and communication data. The intelligent controller is designed using the learning stochastic automata theory. Using the data received from on-board sensors, two automata (one for lateral actions, one for longitudinal actions) can learn the best possible action to avoid collisions. The system has the advantage of being able to work in unmodeled stochastic environments, unlike adaptive control methods or expert systems. Simulations for simultaneous lateral and longitudinal control of a vehicle provide encouraging results