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Full-Text Articles in Physical Sciences and Mathematics

Investigating Three Decades Of Vegetation Change In A Mojave Desert Mountain Range, Chris Lee Roberts May 2012

Investigating Three Decades Of Vegetation Change In A Mojave Desert Mountain Range, Chris Lee Roberts

UNLV Theses, Dissertations, Professional Papers, and Capstones

This project is a vegetation change study spanning 29 years in the Newberry Mountains of Southern Nevada. Long term monitoring data are crucial for understanding the effects of climate change on vegetation dynamics. Successful management intervention in vegetation change will require identification of early indicator plant species and their responses to climatic cues. This project is one of the oldest comparisons of resurveyed Mojave vegetation community plots with repeatable methodology and the longest survey interval reported for the southeastern Mojave Desert. 103 plots were relocated and resurveyed based on data methods in Jim Holland's thesis titled "A Vegetative Analysis of …


The Effects Of Salt Diapirs On The Thermal Maturity Of Surrounding Sediments In The Western Pyrenees, Spain, Nicholas Martin Downs May 2012

The Effects Of Salt Diapirs On The Thermal Maturity Of Surrounding Sediments In The Western Pyrenees, Spain, Nicholas Martin Downs

UNLV Theses, Dissertations, Professional Papers, and Capstones

Salt diapirs have been modeled as having a large effect on the thermal maturity of surrounding sediments as a result of the high thermal conductivity contrast between halite and other lithologies. The goal of this study was to confirm these and other theoretical predictions through sampling of three salt structures in the western Pyrenees, Spain. Stratigraphic units around these three diapirs were targeted based on their lithologies and positions relative to the diapirs. Samples were analyzed for vitrinite reflectance and quartz cementation to determine their levels of thermal maturity. Remote sensing instruments were used to attempt to measure present day …


Buffering Pv Output During Cloud Transients With Energy Storage, Yacouba Moumouni May 2012

Buffering Pv Output During Cloud Transients With Energy Storage, Yacouba Moumouni

UNLV Theses, Dissertations, Professional Papers, and Capstones

Consideration of the use of the major types of energy storage is attempted in this thesis in order to mitigate the effects of power output transients associated with grid-tied CPV systems due to fast-moving cloud coverage. The approach presented here is to buffer intermittency of CPV output power with an energy storage device (used batteries) purchased cheaply from EV owners or battery leasers. When the CPV is connected to the grid with the proper energy storage, the main goal is to smooth out the intermittent solar power and fluctuant load of the grid with a convenient control strategy. This thesis …


Evaluation Of Highly Efficient Distribution Transformer Design And Energy Standards Based On Load, James Sanguinetti May 2012

Evaluation Of Highly Efficient Distribution Transformer Design And Energy Standards Based On Load, James Sanguinetti

UNLV Theses, Dissertations, Professional Papers, and Capstones

Power distribution transformers have been prevalent in commercial building distribution systems since the inception of modern commercial electricity. Yet as more and more manufactures seek to improve transformer efficiencies by making changes to the design of the transformer itself, a fundamental concept may be overlooked - the impact transformer demand sizing has on power losses. When modern transformers are improperly sized for the application they will be installed for they are not being utilized at their optimum design loading range, which may impact operating efficiency.

This thesis will aim to test and evaluate modern day transformer design coupled with currently …


Improving Efficiency And Capacity Of Hydro-Turbines In The Western United States, Hoover Dam, Jonathan Sanchez May 2012

Improving Efficiency And Capacity Of Hydro-Turbines In The Western United States, Hoover Dam, Jonathan Sanchez

UNLV Theses, Dissertations, Professional Papers, and Capstones

The goal for this thesis is to minimize clearances and tolerances, in order to prevent water leakage. A proper seal on the seal rings does not let excess water flow through the turbine runner, thus conserving more water and wasting less energy. Moreover, water leakage past worn wear plates allows for an extra load for the turbine when operating in condense mode. When the wicket gates are closed, water leakage past worn plates wastes mechanical energy in the water; thus, decreasing the efficiency of the Francis turbine, especially when operating at partial loads. Furthermore, the wicket gates also known as …


Dynamic Modelling Of Single Phase Grid Connected Photovoltaic System, Gopi Krishna Ari May 2012

Dynamic Modelling Of Single Phase Grid Connected Photovoltaic System, Gopi Krishna Ari

UNLV Theses, Dissertations, Professional Papers, and Capstones

Grid-connected photovoltaic (PV) power systems have been sustaining an exponential growth rate during the past decade. This steep growth is driven by a growing concern about climate change, the adoption of an aggressive regional renewable portfolio standard, rebates and tax incentives, and reduction in PV system cost. One of the main technical barriers that can ultimately limit further PV penetration is the fast variations in the PV system's output power induced by cloud transients. Such events are known to cause voltage fluctuations which may lead to excessive operations of voltage regulation equipment and light flickering.

Solar irradiance variability, which can …


Deciphering The Evolution Of Ore Fluids At The Batu Hijau Copper-~Gold Porphyry Deposit, Sumbawa, Indonesia, Jordan Thomas Armstrong May 2012

Deciphering The Evolution Of Ore Fluids At The Batu Hijau Copper-~Gold Porphyry Deposit, Sumbawa, Indonesia, Jordan Thomas Armstrong

UNLV Theses, Dissertations, Professional Papers, and Capstones

Fluid inclusions contained within quartz veins from the Batu Hijau Cu-Au porphyry deposit in Indonesia were analyzed to track the evolution of fluid temperature, pressure, and composition during the formation of the deposit to better understand the formation of this and other Cu-Au porphyry deposits in order aid future exploration. A combination of petrography, microthermometry, synchrotron x-ray fluorescence, and laser ablation-inductively coupled plasma-mass spectrometry were used to determine the temperature, pressure, and compositional aspects of the deposit.

Four types of fluid inclusions were recognized at Batu Hijau based on the volume percent of the vapor bubble; inclusions were classified as …


Developing A Simulation Model For Power Demand Control Analysis And Privacy Protection In Smart Grid, Sungchul Lee May 2012

Developing A Simulation Model For Power Demand Control Analysis And Privacy Protection In Smart Grid, Sungchul Lee

UNLV Theses, Dissertations, Professional Papers, and Capstones

With the growing awareness of the need for Smart Grid, various countries are taking initiatives for developing Smart Grid. However, there is limited research on utilizing Smart Grid for Power Demand Control compared to the other areas such as Smart Grid communication network or renewable energy integration. Therefore, this study attempts to help the current Outage Management System by creating a Simulator that allows an intuitive power demand control analysis. Electrical usage is simulated by taking various inputs including the number of houses, family size, work and life patterns, electrical devices, time, etc. For accurate estimate of family and life …


The Zeta Function Of Generalized Markoff Equations Over Finite Fields, Juan Mariscal May 2012

The Zeta Function Of Generalized Markoff Equations Over Finite Fields, Juan Mariscal

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this paper is to derive the Hasse-Weil zeta function of a special class of Algebraic varieties based on a generalization of the Markoff equation. We count the number of solutions to generalized Markoff equations over finite fields first by using the group structure of the set of automorphisms that generate solutions and in other cases by applying a slicing method from the two-dimensional cases. This enables us to derive a generating function for the number of solutions over the degree k extensions of a fixed finite field giving us the local zeta function. We then create an …


Natural And Constructed Wetlands For Ecosystem And Engineering Services In The Arid And Semi-Arid Regions, Achyut Raj Adhikari May 2012

Natural And Constructed Wetlands For Ecosystem And Engineering Services In The Arid And Semi-Arid Regions, Achyut Raj Adhikari

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Las Vegas Wash (LVW) has undergone significant wetlands degradation and soil erosion over the past thirty years due to increasing flow resulting from urbanization and large rainfall events in the Las Vegas Valley Watershed. The increased flow and associated pollution load in the LVW and its adverse impact in Lake Mead have alerted stakeholders to pay a greater attention to explore alternative measures for rehabilitation of wetland ecosystems. This dissertation, using the case of changes in LVW, analyzes and describes ecological and engineering services provided by wetlands in arid and semi-arid regions and provides a knowledge base that can …


Burial And Exhumation History Of Mississippian Strata In East-Central Nevada, Yuki Yunika Agulia May 2012

Burial And Exhumation History Of Mississippian Strata In East-Central Nevada, Yuki Yunika Agulia

UNLV Theses, Dissertations, Professional Papers, and Capstones

Zircon (U-Th)/He analyses and vitrinite reflectance (Ro) analyses were performed on a suite of Mississippian sedimentary rocks collected in east-central Nevada in order to test Permian exhumation described in a previous study.

The zircon analyses produced three clusters of ages: 1) older than, 2) similar to, and 3) younger than depositional age. The majority of zircons shows ages that are older than the sandstone deposition age. Young ages were recorded in three localities that may indicate reset ages/residence within the (U-Th)/He partial retention zone (HePRZ). Moderate-high ratios of Th/U may indicate a magmatic source. Vitrinite reflectance (Ro) analyses show values …


Evaluating Recharge And Dynamics Of Flow In The Lower Virgin River Basin, Usa: Interpretation Of Hydrochemical And Stable Isotopic Data, Joseph Asante May 2012

Evaluating Recharge And Dynamics Of Flow In The Lower Virgin River Basin, Usa: Interpretation Of Hydrochemical And Stable Isotopic Data, Joseph Asante

UNLV Theses, Dissertations, Professional Papers, and Capstones

Because of the complex geologic setting of the Basin and Range province, groundwater flow systems of the Intermountain basins of the southwestern United States are complex and remain poorly understood. Understanding these flow systems is important for water budgeting on a regional and local scale, and development of robust numerical groundwater models for sustainable water use and protection of water-dependent ecosystems. Although for decades hydrochemistry and isotopes have been used to characterize and trace subsurface water and surface water, effectively interpreting these data are still challenging, which can be attributed to existing subjective grouping of these data and the lack …


Chemical Weathering Of The Mafic Minerals Serpentine And Olivine In Natural Environments, Julie Lynn Baumeister May 2012

Chemical Weathering Of The Mafic Minerals Serpentine And Olivine In Natural Environments, Julie Lynn Baumeister

UNLV Theses, Dissertations, Professional Papers, and Capstones

Chemical weathering is a critical process that plays a key role in controlling the chemistry of natural waters, the cycling of atmospheric carbon dioxide, and the formation of soil. The weathering of silicate minerals is important because the Earth's crust is composed of approximately 92 weight percent silicate minerals. Despite an extensive literature on mineral dissolution and kinetics, relatively few studies have examined weathering of the mafic minerals serpentine and olivine, especially in a natural environment. The first chapter of this thesis provides an introduction to the minerals serpentine and olivine. The second chapter of this thesis examines the important …


The Fluvial Muddy Creek Formation Near Overton, Nevada, Carl Taylor Swenberg May 2012

The Fluvial Muddy Creek Formation Near Overton, Nevada, Carl Taylor Swenberg

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Muddy Creek Formation (MCF) may represent an ancestral Colorado River deposit. To test this hypothesis, I mapped exposures of the MCF within the Virgin River Depression (VRD), a rift basin in the central Basin and Range. This is the first study to analyze fluvial MCF facies and test their viability as ancestral Colorado River deposits.

Mapping, paleocurrent analysis, conglomerate provenance, and architectural elements analysis were used in order to characterize the fluvial MCF near Overton NV. Architectural elements analysis revealed that MCF fluvial facies are most closely associated with those of a high-energy sand-bed braided river system. These results …


The Behavior Of Zircon During Partial Melting In Anatectic Migmatites: Insights To Metamorphism, Deformation And Tectonism In The Central Santa Fe Range, Northern New Mexico, Michelle Renee Stropky May 2012

The Behavior Of Zircon During Partial Melting In Anatectic Migmatites: Insights To Metamorphism, Deformation And Tectonism In The Central Santa Fe Range, Northern New Mexico, Michelle Renee Stropky

UNLV Theses, Dissertations, Professional Papers, and Capstones

Three lithologic assemblages exposed in the central Santa Fe Range, northern New Mexico include (1) a septum of Proterozoic low temperature (~700oC, 5.5 kbars), semi-pelitic anatectic migmatites surrounded by (2) deformed megacrystic biotite granite that is intruded by (3) discrete plutons of largely undeformed hornblende biotite tonalite. Metamorphic fabrics in the migmatite record three deformation events (D1 - D3); a composite S1/S2 fabric (D1 and D2) that formed contemporaneous with anatexis and is folded about a southwest plunging map-scale (D3) antiform. The megacrystic granite exhibits a pervasive S1 subsolidus foliation that parallels the S1/S2 fabric in the migmatite and is …


From The Foreland To The Hinterland: Taphonomy Across The Cretaceous To Paleogene Sevier Retroarc Region Of Nevada, Joshua William Bonde May 2012

From The Foreland To The Hinterland: Taphonomy Across The Cretaceous To Paleogene Sevier Retroarc Region Of Nevada, Joshua William Bonde

UNLV Theses, Dissertations, Professional Papers, and Capstones

Until 2004 very little paleobiology, let alone paleoecology, had been studied within exposures of the Sevier retro-arc foreland and hinterland, in the state of Nevada. This is due largely to poor and spotty exposure. This study focuses on taphonomic processes within three stratigraphic intervals in the foreland and hinterland of the Sevier retro-arc region, and what these taphonomic indicators reveal about the geography of the hinterland.

First, the Willow Tank Formation of southern Nevada was deposited in the foredeep of the Sevier retroarc foreland basin. This unit represents a multi-channel, aggradational, fluvial system that drained the Sevier highlands to the …


Spawning, Veliger Growth And Desiccation Of Dreissena Bugensis, Lynn Schwaebe May 2012

Spawning, Veliger Growth And Desiccation Of Dreissena Bugensis, Lynn Schwaebe

UNLV Theses, Dissertations, Professional Papers, and Capstones

Quagga (Dreissena bugensis) mussel veliger growth was compared under two dietary conditions: 1) only seston present in Lake Mead water; and 2) Lake Mead seston plus algae (Isochrysis galbana). Shell length, width, and area were compared as a function of time for the two treatments. It was expected that mussels would exhibit faster growth when supplemented with I. galbana than with Lake Mead water alone. However, no significant difference was observed between the control and I. galbana treatments. This result was unexpected and may have been caused by water quality, the nutritional content of Lake Mead seston, and/or over feeding. …


The Hospitality Industry’S Response To Climate Change: Is The Response Sufficient?, Paul Michael Carlson Apr 2012

The Hospitality Industry’S Response To Climate Change: Is The Response Sufficient?, Paul Michael Carlson

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to explore the serious consequences that global warming and climate change pose for the planet and its inhabitants, and to shed light on the hospitality industry’s contribution to the problem. The study further sought to examine whether the hospitality industry is doing their part in implementing “green” programs to combat its negative contribution to climate change.


A Green Marketing Guideline For The Cruise Industry In North America, Xi Guo Apr 2012

A Green Marketing Guideline For The Cruise Industry In North America, Xi Guo

UNLV Theses, Dissertations, Professional Papers, and Capstones

Purpose: The purpose of this professional paper is to develop a guideline of green marketing strategies for cruise managers in North America.

Statement of objectives: This paper will develop a customer relationship model according to the literature review of customer behavior and customer relationships in the hospitality industry. Meanwhile, the characteristics of green customers and the most popular green practices in the hotel and restaurant industry, and current sustainable achievements in the cruise industry will be investigated respectively. The green marketing guideline will be explored basing on the customer relationship model and the investigations of green customers and green practices …


Running Head: Sustainability Framework Applied To Integrated Resort 1 International Standard Of Sustainability Framework Applied To Integrated Resorts, Jong Hwa Jeon Apr 2012

Running Head: Sustainability Framework Applied To Integrated Resort 1 International Standard Of Sustainability Framework Applied To Integrated Resorts, Jong Hwa Jeon

UNLV Theses, Dissertations, Professional Papers, and Capstones

Purpose

The purpose of this study is to explore the extent to which Las Vegas integrated resorts apply measurement framework for sustainability. It will scrutinize and explore the existing sustainability strategies and practices, and look into several plausible ways to improve the sustainability movement that the companies in hospitality industry currently have. The paper will also look into the tracking and measuring system in consuming resources and the equivalent common actions taken by the management of the hospitality companies. From there, the paper will discuss the Global Reporting Initiative (GRI) guideline and establish if the companies have aligned their efforts …


Exploration Of Human-Computer Interaction (Hci) Applications In Hospitality Industry, Jia Wei Apr 2012

Exploration Of Human-Computer Interaction (Hci) Applications In Hospitality Industry, Jia Wei

UNLV Theses, Dissertations, Professional Papers, and Capstones

Purpose: The purpose of this professional paper is to explore and identify the best practices in Human-Computer Interaction (HCI) applications and use within the hospitality industry.

Statement of Objectives: To accomplish the stated purpose, first, the paper will provide the universal definition of HCI applications and define HCI within the context of hospitality industry. Second, the paper will gather and categorize information, such as the standards of designing HCI applications, from other fields of study such as informatics. Third, the paper will gather existing examples of HCI applications across different areas within the hospitality industry, such as the front desk …


Marketing Analysis For Bonk Knob Shoals Located In Van Buren County, Tennessee, Lillian Lee Ehrmann Apr 2012

Marketing Analysis For Bonk Knob Shoals Located In Van Buren County, Tennessee, Lillian Lee Ehrmann

UNLV Theses, Dissertations, Professional Papers, and Capstones

Purpose: The purpose of this paper is to provide Alfred Crabtree, owner of Bonk Knob Shoals, with a marketing plan. Bonk Knob Shoals will be an upscale campsite nearby Spencer, TN in Van Buren County.

Statement of Objective: Bonk Knob Shoals is currently under development and the owner wants to gain insight to LOHAS tourists, so he can create a suitable business plan to attract people in that niche market. Marketing is a huge component of the business plan because Crabtree believes a significant amount of resources will be needed to increase tourism awareness of the upscale campsite, …