Physical Sciences and Mathematics Commons^™

Mafic Volcanism In The Colorado Plateau: Basin And Range Transition Zone, Hurricane, Utah, Alexander Sanchez

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Hurricane volcanic field (HVF) is a small-volume (0.48 km³) mafic volcanic field in the Colorado Plateau/Basin & Range Transition Zone located in the eastern part of the St. George basin in southwestern Utah. Strombolian-Hawaiian style eruptions produced thin (10 m) a'a lava flows and cinder (scoria) cones composed of vesicular basalt, bombs and agglutinate. Radiometric dating and geologic relationships demonstrate that the HVF formed over a period of at least 100,000 years. In the upper crust, magma probably rose along joints in sedimentary rocks because chains of volcanic vents follow joint orientation maxima in sedimentary rocks.

Three …

Tectonic Denudation Of Mesozoic Contractile Structures By A Low-Angle Normal Fault And Associated Faults, Southern White Pine Range, Nevada, Holly Langrock

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Blackrock Canyon area in the southern White Pine Range, Nevada mostly consists of the highly extended upper plate of a low-angle normal fault, the Blackrock fault. The post-31.3 Ma Blackrock fault places upper Paleozoic sedimentary rocks and overlying Tertiary volcanic rocks of the Garret Ranch Group in its hangingwall against a 50 degrees E-dipping homocline of Cambrian through Mississippian rocks in its footwall. The 15 to 30 degrees W-dipping Blackrock fault is non-planar and consists of two fault segments and a pronounced corrugation, the Bull Spring corrugation. These geometric irregularities suggest the slip direction on the fault was east-southeast …

Geology And Geochemistry Of Tertiary Volcanic Rocks In The Northern Reveille And Southern Pancake Ranges, Nye County, Nevada, Kelly Brian Rash

UNLV Theses, Dissertations, Professional Papers, and Capstones

The northern Reveille and southern Pancake Ranges, located in the south-central Great Basin, experienced a prolonged history of Tertiary volcanism. Volcanic activity in this area began with the eruption of large-volumes of ash-flow tuffs from calderas of the central Nevada caldera complex. The Reveille Range and the southernmost portion of the Pancake Range are the site of two calderas that are the sources for the tuff of Goblin Knobs and tuff of northern Reveille Range. The tuff of Goblin Knobs (70.4-75.3 wt.% SiO₂) erupted from the caldera of Goblin Knobs (25.6 Ma) and is the thickest (~1700 m) …

Geochemical Evolution Of A Mid-Miocene Synextensional Volcanic Complex: The Dolan Springs Volcanic Field, Northwestern Arizona, Scott Michael Mcdaniel

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Dolan Springs volcanic field (DSV), of northwestern Arizona, is dominated by andesite and basaltic-andesite flows and breccias, with minor amounts of basalt, rhyolite, and ash-flow tuff. Geochemistry is used here as a tool to evaluate the roles and contributions of the lithospheric and asthenospheric mantles to magmatism related to Miocene extension in the Colorado River extension corridor (CREC). The majority of synextensional volcanic rocks in the DSV are geochemically similar to regional trends, but rare tholeiitic basalts erupted near the end of extension. The tholeiites have trace element signatures similar to ocean island basalt (OIB), but have isotopic values …

Intelligent Control Of Vehicles: Preliminary Results On The Application Of Learning Automata Techniques To Automated Highway System, Cem Unsal, John S. Bay, Pushkin Kachroo

Electrical & Computer Engineering Faculty Research

We suggest an intelligent controller for an automated vehicle to plan its own trajectory based on sensor and communication data received. Our intelligent controller is based on an artificial intelligence technique called learning stochastic automata. The automaton can learn the best possible action to avoid collisions using the data received from on-board sensors. The system has the advantage of being able to work in unmodeled stochastic environments. Simulations for the lateral control of a vehicle using this AI method provides encouraging results.

Management Of Pesticide Related Soil Contamination In Tulare County, California: Remediation And Prevention Options, Nickolas Keoni Akana

UNLV Theses, Dissertations, Professional Papers, and Capstones

The case study chosen for research is the Remedial Action Plan (RAP) summary report of Remedial Investigations of the Harmon Field contaminated site located near the town of Pixley, in Tulare County, California. "These reports were prepared in accordance with a directive from the California Environmental Protection Agency (Cal-EPA), formerly the California Department of Health Services (DHS). (Canonie, 1996).

Harmon Field is a hundred acre field located at 1494 South Airport Road. The airfield has been in full operation since 1952. The uses of the airport are all agriculturally related. The primary use is for crop duster operations. (Canonie 1996). …

Nutrient Limitation In A Southwestern Desert Reservoir: Eutrophication Of Las Vegas Bay, Lake Mead, Nevada, Davine M. Lieberman

Publications (WR)

Algal bioassay tests were conducted with Selenastrum capricornutum and natural algae on inner Las Vegas Bay, Lake Mead, Nevada, from December 1992 through September 1993, to identify any nutrient limitation in an area of the reservoir that has experienced problems associated with severe nutrient enrichment. Three areas were sampled based on a gradient of water quality conditions that existed in Las Vegas Bay (LVB). Disodium ethylenedinitrilotetraacetate (EDTA) significantly stimulated algal growth compared to non-EDTA treatment. Algal bioassays indicated that phosphorus (P) was the primary limiting nutrient at all stations for most of the test dates. Chl a response with EDTA …

Comparison Of Time-Domain Reflectometry Performance Factors For Several Dielectric Geometries: Theory And Experiments, S. V. Maheshwarla, R. Venkatasubramanian, Robert F. Boehm

Electrical & Computer Engineering Faculty Research

We propose three nontraditional dielectric geometries and present an experimental and theoretical analysis and comparison of time domain reflectometry (TDR) performances for them. The traditional geometry (the probes inserted in material of essentially infinite extent) is compared to three nontraditional geometries where the probes are affixed outside of a core sample, inside of a bore, or flat on the surface of a semi-infinite solid. Our derivation relates the velocity of electromagnetic wave propagation to the complex permittivities and permeabilities of the media and the geometry for the three nontraditional configurations. Experimental results for air, styrofoam, dry sand, wet sand of …

Angle-Resolved Photoelectron Spectroscopy Of C60, T. Liebsch, O. Plotzke, Franz Heiser, U. Hergenhahn, Oliver Hemmers, R. Wehlitz, J. Viefhaus, B. Langer, S. B. Whitfield, U. Becker

Environmental Studies Faculty Publications

Angle-resolved photoelectron spectra of gaseous C₆₀ were recorded in the photon energy regions from 21 to 108 eV and from 295 to 320 eV. Partial cross sections σ and the angular distribution anisotropy parameter β vary significantly with photon energy, particularly in the near-threshold region of the valence and the core ionization regimes. Some of these effects may be attributed to scattering of the outgoing photoelectron by the atoms of the ionized C₆₀ molecule. Our results indicate that the observed satellites of the C(1s) main line are most likely of shake-up character. Low-energy electrons emitted below the shake-off …

Vibrational-State-Dependent Decay Of The Co C(1s) Excitation, N. Saito, Franz Heiser, Oliver Hemmers, A. Hempelmann, K. Wieliczek, J. Viefhaus, U. Becker

Environmental Studies Faculty Publications

Molecular ionization and ionic fragmentation of core excited CO valence and Rydberg states are studied by partial-ion-yield spectroscopy at vibrational resolution. The vibrational intensities of the Rydberg excitations differ significantly depending on the ionization and/or fragmentation channel. The observed intensity variations are explained by nondissociative excited final ionic states of the subsequent molecular Auger decay. The vibrational levels of these final states become selectively depopulated due to interaction with dissociative decay channels leading to ionic fragmentation.

A Petrographic And Fluid Inclusion Study Of The Purple Vein And Post/Betze Orebodies, Carlin, Nevada, Jan B. Lamb

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Purple Vein (Meikle Mine) and Post/Betze orebodies, two Carlin-type, gold deposits, display important differences in size, alteration, silicification, pyritization, and gold grade. A core hole was examined from each deposit to gather petrographic and microthermometric data to determine the mineral paragenesis, to determine fluid pressure, temperature, and composition to compare of the two orebodies, and to determine depths of formation.

The parageneses determined were divided into three stages. (1) The Early Mineralization Stage contains quartz, pyrobitumen, barite, sphalerite, sulfosalts, quartz, and pyrite in the Purple Vein deposit and consists of calcite in the Post/Betze deposit. High salinity basinal brines, …

An Understanding Of Factors Controlling Isotopic Ratios Of Wine As A Potential Surrogate Of Past Precipitation, Eric Alan Caldwell

UNLV Theses, Dissertations, Professional Papers, and Capstones

Precipitation, vapor water, ground water, soil water, grape berry and grape leaf water, grape must, and vintage wines were collected from northern California for stable isotopic analysis. An understanding of factors controlling isotopic ratios of wine allows evaluation of wine as a surrogate of past precipitation. Stable isotopic compositions of grape berry waters collected at Charles Krug Winery in Napa Valley. CA range from -31 to -17 per mil in 8D and +7.2 to +15.3 per mil in 8180, and plot along a transpiration line of slope 2. 7. Grape leaf waters range from -25 to +5 per mil in …

Resource Use Conflict In New York City's Catskill Watersheds: A Case For Expanding The Scope Of Water Resource Management, Krystyna Anne Stave

Public Policy and Leadership Faculty Publications

In New York City's water supply watersheds, controversy over water quality protection underscores both the need to expand the scope of water resource management and the challenges to doing so. This paper describes the response of watershed residents to !'Jew York City's efforts to avoid filtration mandated by the 1986 Safe Drinking Water Act Amendments and 1989 Surface Water Treatment Rule. The emergence of a spectrum of stakeholder groups representing land owners, sport fishermen, businesses, environmental groups and local communities has brought social and economic issues not previously part of the City's water management program to the center of the …

The Study Of Yucca Mountain For A Possible Nuclear Storage Facility Science Vs. Politics, Anna Leske

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this paper is to determine whether scientific or political methods were used by the of the United States Congress in the study of the nuclear waste storage facility in Yucca Mountain, Nevada. The history nuclear power and the history of the Johnston compromise that lead to the elimination of Texas and Washington States as possible sites for the repository is explained. A review of the conflicts between Nevada politicians and the U.S. Congress over the designation of Yucca Mountain as the sole study for a permanent storage site of the nation's high-level nuclear waste is addressed along …

Limiting Growth In Las Vegas - A Necessary Growth Strategy For The Twenty-First Century, Cheryl Ann Frassa

UNLV Theses, Dissertations, Professional Papers, and Capstones

Land development in the Las Vegas Valley continues at an unprecedented rate and future growth will no doubt be strongly advocated. Yet, water resources in this desert area are finite, and in the near future, supply will fall short of demand. Plans are underway to supplement the existing supply, and proposals to secure additional sources are under investigation. But there are no guarantees these ambitious endeavors will materialize. In light of the pending water crisis, the pervasive "growth at all cost" policies now dominant in the valley must be abandoned and more realistic land-use policies developed; ones based on the …

Updating The Colorado River Compact, Jeffrey A. Freer

UNLV Theses, Dissertations, Professional Papers, and Capstones

Water is essential to life in the arid environment of the western United States. For centuries, humans have used the Colorado River to fulfill their needs and until the past 100 years, the use of the river was sustainable. Over the last 100 years, the Colorado River has been dammed and diverted to "reclaim" the arid west for man's use. In 1946, a Department of the Interior report stated that "Tomorrow the Colorado will be utilized to the very last drop. Its water will convert thousands of additional acres of sagebrush desert to flourishing farms and beautiful homes for servicemen, …

Using Gis To Identify Critical Areas For Water Quality Protection In New York City's Water Supply System, Paul K. Barten, Krystyna Anne Stave

Public Policy and Leadership Faculty Publications

The protection of water quality at its source — the watershed — recognizes that minimizing land use impacts and allowing natural processes to provide in situ biological treatment can complement conventional engineering methods. In contrast to the enormous costs projected for drinking water filtration, the judicious application of watershed management principles and practices is a way to balance the needs of people with the capacity of the natural resource base over time. This paper describes the development and initial application of a geographic information system (GIS) to a ortion of New York City's 2,000 square mile water supply system, the …

Observation Of Parity-Unfavored Transitions In The Nonresonant Photoionization Of Argon, B. Langer, J. Viefhaus, Oliver Hemmers, A. Menzel, R. Wehlitz, U. Becker

Environmental Studies Faculty Publications

Single-photon ionization of an atom or molecule can be subdivided into parity-favored and -unfavored transitions, the latter characterized by electron emission, preferentially perpendicular to the electric vector. The nonresonant existence of these transitions is shown experimentally and studied over an extended energy range for a variety of satellite transitions in atomic argon. The spectra exhibit several clearly resolved satellite lines with strongly negative β values close to -1, independent of the photon energy. The results confirm the corresponding predictions of angular-momentum transfer theory.

Design And Performance Of The Advanced-Light-Source Double-Crystal Monochromator, G. Jones, S. Ryce, Dennis W. Lindle, B. A. Karlin, J. C. Woicik, Rupert C. Perera

Chemistry and Biochemistry Faculty Research

A new “Cowan type” double-crystal monochromator, based on the boomerang design used at National Synchrotron Light Source (NSLS) beamline X-24A, has been developed for beamline 9.3.1 at the Advanced Light Source (ALS), a windowless ultrahigh vacuum beamline covering the 1-6 keV photon-energy range. Beamline 9.3.1 is designed to simultaneously achieve the goals of high energy resolution, high flux, and high brightness at the sample. The mechanical design of the monochromator has been simplified, and recent developments in technology have been included. Measured mechanical precision of the monochromator shows significant improvement over existing designs. In tests with x-rays at NSLS beamline …

High-Brightness Beamline For X-Ray Spectroscopy At The Advanced Light Source, Rupert C. Perera, G. Jones, Dennis W. Lindle

Chemistry and Biochemistry Faculty Research

Beamline 9.3.1 at the Advanced Light Source (ALS) is a windowless beamline, covering the 1-6 keV photon-energy range, designed to achieve the goals of high energy resolution, high flux, and high brightness at the sample. When completed later this year, it will be the first ALS monochromatic hard-x-ray beamline, and its brightness will be an order-of-magnitude higher than presently available in this energy range. In addition, it will provide flux and resolution comparable to any other beamline now in operation. To achieve these goals, two technical improvements, relative to existing x-ray beamlines, were incorporated. First, a somewhat novel optical design …

Structure Of Woody Riparian Vegetation In Great Basin National Park, S. D. Smith, K. J. Murray, F. H. Landau, A. M. Sala

Life Sciences Faculty Research

The community composition and population structure of the woody riparian vegetation in Great Basin National Park are described. Community analyses were accomplished by sampling 229 plots along an elevational gradient of 8 major stream systems in the Park. TWINSPAN analysis identified 4 primary species groups that were characterized by Populus tremuloides (aspen), Abies concolor (white fir), Rosa woodsii (Woods rose), and Populus angustifolia (narrowleaf cottonwood) as dominants, respectively. Detrended Correspondence Analysis (DECORANA) showed that the most important environmental factors associated with the distribution of species were elevation and slope, with flood-related physiographic factors having a secondary effect. Analysis of size-class …