Physical Sciences and Mathematics Commons^™

Isolated Ramp Metering Feedback Control Utilizing Mixed Sensitivity For Desired Mainline Density And The Ramp Queues, Pushkin Kachroo, Kaan Ozbay, Donald E. Grove

Electrical & Computer Engineering Faculty Research

This paper presents a feedback control design for isolated ramp metering control. This feedback control design, unlike the existing isolated feedback ramp controllers, also takes into account the ramp queue length. Using a nonlinear H∞ control design methodology, we formulate the problem in the desired setting to be able to utilize the results of the methodology.

Photoelectron Spectroscopy And The Dipole Approximation, Oliver Hemmers, Dennis W. Lindle

Environmental Studies Faculty Publications

Over the past three decades, the dipole approximation has facilitated a basic understanding of the photoionization process in atoms and molecules. Advances in gas-phase photoemission experiments using synchrotron radiation have recently highlighted nondipole effects at relatively low photon energies while probing the limits of the dipole approximation. Breakdowns in this approximation are manifested primarily as deviations from dipolar angular distributions of photoelectrons. Detailed new results demonstrate nondipolar angular-distribution effects are easily observable in atomic gases at energies well below 1 keV, and, in molecules, a previously unexpected phenomenon greatly enhances the breakdown of the dipole approximation just above the core-level …

Experimental Investigation Of Steel Corrosion In Lead Bismuth Eutectic (Lbe): Characterization, Species Identification, And Chemical Reactions, John Farley, Dale L. Perry

Transmutation Sciences Materials (TRP)

The goal of the present research is to achieve a basic understanding of corrosion of steels by Lead Bismuth Eutectic (LBE). Liquid LBE is under consideration in the transmuter as both a coolant and a target material. There have been studies of LBE, especially by the Russians, but a fundamental understanding and verification of its role in the corrosion of steels is still very 2 incomplete. Post-experiment testing and analysis will be performed on steel samples that have been in intimate contact with LBE. Chemical alterations and resulting chemical species will be measured at the steel surface. Techniques to be …

The Procedure For Determining And Quality Assurance Program For The Calculation Of Dose Coefficients Using Dcal Software, A. Arndt, John P. Shanahan, C. Gold, R. Brey, T. Gesell, Phillip W. Patton, Mark Rudin, K. Eckerman, V. Rusetski, S. Pagava

Transmutation Sciences Physics (TRP)

The development of a spallation neutron source with a mercury target may lead to the production of rare radionuclides. The dose coefficients for many of these radionuclides have not yet been published. A collaboration of universities and national labs has taken on the task of calculating dose coefficients for the rare radionuclides using the software package: DCAL. The working group developed a procedure for calculating dose coefficients and a quality assurance (QA) program to verify the calculations completed. The first portion of this QA program was to verify that each participating group could independently reproduce the dose coefficients for a …

Durango Hills Water Resource Center, City Of Las Vegas, Nevada

Publications (WR)

No abstract provided.

Southern Nevada Water Authority, Statler Hasley

UNLV Theses, Dissertations, Professional Papers, and Capstones

The arid Southwest of the United States is confronted with increasing water demands. Past efforts to meet water demand have been directed toward development of scarce water resources. Now the times are changing and conservation programs are being instituted to expand supplies for the growing population. In Las Vegas, the tides are shifting to conservation programs. The Southern Nevada Water Authority (SNWA), an agency comprised of the local water utilities, have united to find new sources of water to feed the growing city. SNWA has invested a great deal of money into the conservation programs as an alternative to developing …

Alternative Principal Components Regression Procedures For Dendrohydrologic Reconstructions, Hugo G. Hidalgo, Thomas C. Piechota, John A. Dracup

Civil and Environmental Engineering and Construction Faculty Research

Streamflow reconstruction using tree ring information (dendrohydrology) has traditionally used principal components analysis (PCA) and stepwise regression to form a transfer function. However, PCA has several procedural choices that may result in very different reconstructions. This study assesses the different procedures in PCA-based regression and suggests alternative procedures for selection of variables and principal components. Cross-validation statistics are presented as an alternative for independently testing and identifying the optimal model. The objective is to use these statistics as a measure of the model's performance to find a conceptually acceptable model with a low prediction error and the fewest number of …

Final Technical Report For Grant De-Fg01-96ew56093 Nevada Risk Assessment/Management Program (Nramp), Donald H. Baepler, Anthony Hechanova

Nevada Risk Assessment/Management Program

The Nevada Risk Assessment/Management Program (NRAMP) was part of a national effort by the U.S. Department of Energy (DOE) to develop new sources of information and approaches to risk assessment, risk management, risk communication and public outreach as these objectives relate to the ecological and human health effects of radioactive and hazardous material management and site remediation activities. This final report presents a synopsis of the NRAMP effort that occurred from 1995 to 2000. Included in this report is a brief history of NRAMP including a description of the DOE Notice of Program Interest (NOPI) goals and how the NRAMP …

An Examination Of Gasoline Pollutants From Two-Cycle Marine Engines Within Lake Mead National Recreation Area, Brian Carter

UNLV Theses, Dissertations, Professional Papers, and Capstones

Jet skis are a very popular "toy" to have in the United States. They account for almost a third of all boat sales, and their numbers are growing rapidly. Unfortunately jet skis use two-cycle engines that pollute at unacceptable levels. Jet ski motors can emit up to 25% of its fuel right back into the water. This alarmed me and I wanted to take a deeper look into how bad jet skis pollute Las Vegas' primary water source. Lake Mead. I looked into how a two-cycle engine differs from a regular engine and I looked at the actual pollutants a …

Remote Sensing And Geographic Information Systems For Decision Analysis In Public Resource Administration: Case Study In A Southwestern Watershed, William G. Kepner

UNLV Theses, Dissertations, Professional Papers, and Capstones

Alternative futures analysis is a scenario-based approach to regional land planning that attempts to synthesize existing scientific information in a format useful to community decision makers. Typically, this approach attempts to investigate the impacts of several alternative sets of choices preferred by representative stakeholder groups relative to selected environmental or economical endpoints. Potential impacts from each of the scenarios are compared to current conditions of the region in terms of a set of processes that are modeled within a geographic information system. Future conditions are generally examined from the perspective of a recent baseline condition (versus empirically determined using a …

Examination Of The Bureau Of Land Management's Implementation Of The Wild, Free-Roaming Horse And Burro Act At Red Rock National Conservation Area, Christine E. Brehm

UNLV Theses, Dissertations, Professional Papers, and Capstones

For unknown reasons horses went extinct on the North American continent approximately ten thousand years ago and were subsequently reintroduced by Spanish settlers in the 1400's. As European settlers moved westward, horses were perceived as competition for grasslands and their numbers were curtailed. Wild horses were granted Federal protection in 1959 with the passage of the 'Wild Horse Annie' law and further protected with the passage of the Wild, Free-Roaming Horse and Burro Act of 1971. Through the Department of the Interior, the Bureau of Land Management was charged with management of wild horses on public lands. Physical searches of …

Green Sea Turtle (Chelonia Mydas) Hatchlings Success: The Effects Of Artificial Lights And Other Human Impacts, Hui-Yu Tracy Liang

UNLV Theses, Dissertations, Professional Papers, and Capstones

Sea turtles appeared more than 200 million years ago in the late Triassic period. They grow very slowly, taking an average of 25 years to reach sexual maturity, with a life span averaging 40-50 years. From May to October green sea turtles (Chelonia mydas) emerge during the night and follow light cues toward the sea. Recently, beachfront development has increased hatchling mortality rate. When hatchlings emerge from nest, high densities of artificial lights lead them toward the land where they either desiccate and die, or are preyed upon. Short-wavelength high intensity light and the distance of artificial light are the …

Deposition And Uptake Availability Of Lead Shot For Waterfowl At Honeybee Pond Within The Overton Wildlife Management Area, Nevada, Usa, Jason Eckberg

UNLV Theses, Dissertations, Professional Papers, and Capstones

Lead shot has been banned for hunting waterfowl since 1974, but lead poisoning continues to be a major problem in many waterfowl habitats. In December of 1999, soil samples were collected from the Honeybee pond at the Overton Wildlife Management area to determine the lead pellet concentration and the availability of lead shot to waterfowl. There were no shot pellets recovered from the thirty-one samples taken from the pond. Based on this information waterfowl do not appear to be exposed to lead in the pond areas at OWMA.

Two Different Soil Sampling Techniques For Assessing Soil Lead Concentrations At The Overton Wildlife Management Area, Nevada, Kristen E. Falc

UNLV Theses, Dissertations, Professional Papers, and Capstones

During the summer of 1999, soil samples were taken from the Overton Wildlife Management Area (OWMA), located in the Moapa Valley of Clark County, Nevada. Although lead shot has been banned for the hunting of waterfowl since 1986, it is still legal for upland game hunting. The field sampled serves primarily as a dove hunting area and is cultivated. A large sample size was taken to indicate the short-term effects of the deposition of lead shot in the area and a small sample size, the long-term. Lead shot was recovered from 64% of the small samples and the estimated concentration …

An Examination Of A Brownfield: The Former North Las Vegas Armory Site, Rebecca L. Fowler

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis is a case study of the redevelopment project of the former Armory site in Las Vegas, Nevada, a United States Environmental Protection Agency Brownfield Pilot Project. This investigation uses benefit-cost analysis to determine whether the project is economically feasible. This examination includes a description of the Brownfield program, a description of the site, selection criteria, and the proposed future use of it. The results show that the benefits exceed the costs.

Special Event Recycling: The Future Of Unlv's Recycling Program, Katherine A. Baker

UNLV Theses, Dissertations, Professional Papers, and Capstones

The current recycling program on the University of Nevada Las Vegas (UNLV) campus does not have a special event recycling aspect. The purpose of this study was to develop a special event recycling program and make recommendations of how to effectively implement it on the UNLV campus. In order to develop this special event recycling program data was collected through surveys and a pilot study. The data collected was then used to formulate recommendations. Recycling two different kinds of events, a walk and a concert tested those recommendations. Waste stream analyses were done on each event. The waste stream diversion …

Comparative Analysis Of Three Remediation Technologies For The Clean Up Of Petroleum Contaminated Groundwater, Thomas Bouck

UNLV Theses, Dissertations, Professional Papers, and Capstones

This paper will compare three remediation technologies to determine which is the most efficient and effective remediation treatment for a petroleum contaminated groundwater site. The three remediation technologies are in situ bioremediation, in situ air sparging, and air stripping with carbon filtration. This comparison will be done through a literature review. It will take the information derived from the review and then apply it to the information about a petroleum contaminated groundwater location. The comparative analysis will consist of these parameters permit requirements, clean up time, operating and maintenance, and geological factors.

These factors permit requirements, cleanup time, and operating …

Electric-Octupole And Pure-Electric-Quadrupole Effects In Soft X-Ray Photoemission, Andrei Derevianko, Oliver Hemmers, S. Oblad, P. Glans, H. Wang, S. B. Whitfield, R. Wehlitz, I. A. Sellin, W. R. Johnson, Dennis W. Lindle

Environmental Studies Faculty Publications

Second-order [O(k²), k = ω/c] nondipole effects in soft-x-ray photoemission are demonstrated via an experimental and a theoretical study of angular distributions of neon valence photoelectrons in the 100–1200 eV photon-energy range. A newly derived theoretical expression for nondipolar angular distributions characterizes the second-order effects using four new parameters with primary contributions from pure-quadrupole and octupole-dipole interference terms. Independent-particle calculations of these parameters account for a significant portion of the existing discrepancy between experiment and theory for Ne 2p first-order nondipole parameters.

Lifetime Effects On The Dissociation Of Core-Excited N2 And Co Molecules, N. Saito, A. Hempelmann, F. Heiserq, Oliver Hemmers, K. Wieliczek, J. Viefhaus, U. Becker

Environmental Studies Faculty Publications

Vibrational-resolved ion and ion-pair yield spectra of N₂ and CO taken at their 1s⃗π^* resonance excitations reveal decay-channel-dependent core hole lifetimes. The linewidths of the yield spectra tend to be shortened when the number of electrons ejected in the deexcitation process increases, finally becoming narrower than the total ion yield or absorption natural lifetime width of the core-excited states of N₂ and CO, respectively. In contrast to this, the linewidths of the yield spectra for the singly charged molecular ions, N₂⁺ and CO⁺, are shown to be broader than their corresponding natural linewidths. …

Levels Of Synthetic Musks In Municipal Wastewater For Estimating Biota Exposure In Receiving Waters, Lantis Osemwengie

UNLV Theses, Dissertations, Professional Papers, and Capstones

Natural musk (muscone) is a highly prized natural product for use in expensive consumer fragrances. Inexpensive synthetic substitutes have been commercialized over the last 40 years. Two main chemical classes are used commercially — the nitro musks (which fulfilled the original demand for inexpensive fragrance additives for personal care products such as bath soap, body lotions, perfumes, and washing detergents) and the newer polycyclic musks which have musklike smell. The commercial nitro musks include musk ketone, musk moskene, musk ambrette, musk xylene, and musk tibetene. The polycyclics include trade named compounds such as Galaxolide®, Tonalide®, Celestolide®, Traseolide®, Phantolide®, and Cashmeran®, …

Beyond The Dipole Approximation: Angular-Distribution Effects In The 1s Photoemission From Small Molecules, Dennis W. Lindle, Oliver Hemmers, H. Wang, P. Focke, I. A. Sellin, J. D. Mills, J. A. Sheehy, P. W. Langhoff

Environmental Studies Faculty Publications

Over the past two decades, the dipole approximation has facilitated a basic understanding of the photoionization process in atoms and molecules. Recent experiments on the 1s inner shells of small molecules at relatively low photon energies (⩽ 1000 eV) show strong nondipole effects. They are significant and measurable at energies close to threshold, in conflict with a common assumption that the dipole approximation is valid for photon energies below 1 keV.

Mapping The Boulder City Wetlands Using A Global Positioning System (Gps) And A Geographic Information System (Gis), Jennifer Lea Bishop

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Boulder City Wetlands is a constructed wetlands park located in Boulder City, Nevada, approximately 23 miles southeast of Las Vegas, Nevada. Currently, a baseline study of water quality is being conducted in the Boulder City Wetlands. This baseline study of the wetlands is an important step in understanding the development of the Boulder City Wetlands over time. As wastewater is eventually introduced into the existing community tap water running through the wetlands, it is expected that the nitrogen within the water will enhance the growth of vegetation in the surrounding area. Comparing the vegetation growth over time is only …

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) …

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 …

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 …

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 …

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.

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.

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 …