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Full-Text Articles in Physical Sciences and Mathematics

Democracy And The Environment In Latin America, Javier Albert Escamilla Dec 2009

Democracy And The Environment In Latin America, Javier Albert Escamilla

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study examines the ability of democratic and non-democratic states alike to protect the environment. Democracy has long been an important concept in the study of politics and environmental protection is an increasingly important issue in world politics. Advocates of democracy claim democratic states are better able to protect the environment than non-democracies. In contrast there are those that argue democracy's emphasis on individual rights leads to excessive resource consumption. This thesis employs a mixed methods approach to determine if democratic countries protect the environment more than their non-democratic counterparts. In short democracies do protect the environment better than non-democracies …


Trophic Interactions Associated With Indroduction Of The Invasive Quagga Mussel In Lake Mead, Nevada, Eric Michael Loomis May 2009

Trophic Interactions Associated With Indroduction Of The Invasive Quagga Mussel In Lake Mead, Nevada, Eric Michael Loomis

UNLV Theses, Dissertations, Professional Papers, and Capstones

The ecology of Lake Mead is experiencing an uncertain future since the documented arrival of the invasive quagga mussel. Interactions among constituents of the food web will undoubtedly be altered over time, adversely affecting the popular sport fishery. This study is the first in Lake Mead to present historic trends in lower trophic interactions among threadfin shad and zooplankton before, and shortly after, the arrival of quagga mussels. Shad stomach content analysis revealed cladocerans and copepods were the dominant identifiable food items in Las Vegas Bay and Overton Arm of Lake Mead. Baseline energetics data through the use of stable …


Water Quality Changes In A Constructed Wetland At The Springs Preserve In Las Vegas, Nevada, Aaron Mathis Miller May 2009

Water Quality Changes In A Constructed Wetland At The Springs Preserve In Las Vegas, Nevada, Aaron Mathis Miller

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Springs Preserve near downtown Las Vegas, Nevada contains a seven-acre constructed wetland. Springs Preserve managers are planning to use water from the constructed wetland to irrigate creeks immediately north of the wetland. These creeks will be used by a variety ofaquatic wildlife, including endangered amphibians sensitive to harmful metalloids, such as selenium, lead, and arsenic.

In an attempt to answer toxicological questions about contaminant concentrations in the constructed wetland, three metals and metalloids (selenium, arsenic, and lead), two nutrients (nitrogen and phosphorus), and the major ionic species were analyzed at four sampling locations for aqueous concentrations, in two separate …


Flowing Toward Sustainability: Two Stream Adjudications Analyzed Under The Iad Framework, Nancye Lou Bethurem May 2009

Flowing Toward Sustainability: Two Stream Adjudications Analyzed Under The Iad Framework, Nancye Lou Bethurem

UNLV Theses, Dissertations, Professional Papers, and Capstones

One of the most significant problems impacting the western United States today is the lack of naturally occurring water resources, especially during this period of drought and explosive population growth. This has led to intense competition over water use and ownership in the arid and semi-arid regions of the United States. During this period of water resource scarcity, it is extremely important to determine the ownership of water rights in order to implement optimal management systems. Most western states use a system of "general stream adjudications" to make water rights ownership determinations.

General stream adjudications are legal proceedings used to …


Going Green In The Hospitality Industry, Christina Wilson Micioni May 2009

Going Green In The Hospitality Industry, Christina Wilson Micioni

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this research is to examine whether a hotel’s greening efforts are a reason why everyday guests or hospitality professionals choose a hotel. Do meeting planners and business travelers expect certain things while staying at a hotel? Do the personal greening activities of a guest affect their hotel stay? This will also include the housekeeping needs of the guests and why they choose the hotel. The objective of the research will be to discover whether there is guest data to support the need for hotels to become green establishments.


Case Study: Feasibility Analysis Of Renewable Energy Supply Systems In A Small Grid Connected Resort, Jody Robins May 2009

Case Study: Feasibility Analysis Of Renewable Energy Supply Systems In A Small Grid Connected Resort, Jody Robins

UNLV Theses, Dissertations, Professional Papers, and Capstones

This paper presents a case study on the feasibility of a small grid connected resort in the marine west coast climate of Canada to implement a renewable energy supply system. The current industry conditions of three renewable energy systems are explored including small and large wind energy conversion systems, solar photovoltaic cell systems, and energy cell systems. Furthermore, these three systems are evaluated using the power load, wind, and solar radiation information from a specific resort. The renewable energy source assessment and optimization software HOMER (National Renewable Energy Laboratory, US) is used to evaluate the costs and benefits of each …


Substrate Monitoring, Contaminant Monitoring, And Educational Outreach On Quagga Mussels (Dreissena Bugensis) In Lake Mead, Nevada, Sara Ann Mueting May 2009

Substrate Monitoring, Contaminant Monitoring, And Educational Outreach On Quagga Mussels (Dreissena Bugensis) In Lake Mead, Nevada, Sara Ann Mueting

UNLV Theses, Dissertations, Professional Papers, and Capstones

The invasive species, the quagga mussel, Dreissena bugensis, was found in Lake Mead, Nevada-Arizona, USA on January 6, 2007. Since then, researchers have been attempting to quantify the amount of damage these mussels will cause to the lower Colorado River basin. Three projects were implemented in this thesis to research the quagga mussel in Lake Mead. First, a study to determine which types of substrates quagga mussels will grow on preferentially was conducted. Six different substrates, Acrylonitrile Butadiene Styrene (ABS) plastic, High Density Polyethylene (HDPE) plastic, Concrete Underlayment Board (CUB), aluminum, stainless steel and fiberglass, were placed in the Boulder …


The Influence Of Carbon Source Types And Nitrate On The Performance Of The Enhanced Biological Phosphorus Removal Systems, Shamim Ara Begum May 2009

The Influence Of Carbon Source Types And Nitrate On The Performance Of The Enhanced Biological Phosphorus Removal Systems, Shamim Ara Begum

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research focuses on two issues in enhanced biological phosphorus removal (EBPR). The first issue encompasses the effect of the type of carbon sources (i.e. volatile fatty acids and non volatile fatty acids) on the microbiology of EBPR. The second issue deals with the influence of denitrification on EBPR. Few studies have been performed to investigate these two issues. The recent findings on these areas are summarized below to establish the knowledge gaps this dissertation attempted to address. Details on the specific findings can be found in the literature review portion of this proposal.


Characterization Of Iron Oxide Thin Films For Photoelectrochemical Hydrogen Production, Kyle Eustace Nelson George Jan 2009

Characterization Of Iron Oxide Thin Films For Photoelectrochemical Hydrogen Production, Kyle Eustace Nelson George

UNLV Theses, Dissertations, Professional Papers, and Capstones

Solar energy is the most sustainable source of energy available. However, solar applications such as photovoltaic cells represent only a partial solution to weaning our dependence upon fossil fuels. Several methods of storing solar energy are currently being pursued, and chemical storage stands out as a promising option - combining design simplicity with high energy density, with hydrogen being particularly attractive because of its abundance and inherently clean nature. A monolithic Photoelectrochemical (PEC) device that produces hydrogen by electrolyzing water directly from sunlight has the benefit of utilizing "free" solar energy to drive the reaction.

Although α-Fe 2 O 3 …


Desert Varnish As An Indicator Of Modern-Day Air Pollution In Southern Nevada, Piotr Nowinski Jan 2009

Desert Varnish As An Indicator Of Modern-Day Air Pollution In Southern Nevada, Piotr Nowinski

UNLV Theses, Dissertations, Professional Papers, and Capstones

Rock varnish, often called desert varnish, is a slow-growing, manganese-rich coating that accumulates on exposed rock surfaces. The mechanism of varnish formation is not fully understood, however, most authors agree that varnishes derive their components from the atmosphere. The main goal of this study was to demonstrate the potential use of desert varnish as a passive environmental monitor of present and past atmospheric pollution. Analysis of varnishes is a new field that can potentially provide records of pre-anthropogenic levels of atmospheric metals and other environmental pollutants. To evaluate the potential of desert varnish as an environmental monitoring tool, the following …


Systematic Analysis Of Identifying Key Dimensions Of Environmentally And Socially Responsible Hotels, Courtney Suess Jan 2009

Systematic Analysis Of Identifying Key Dimensions Of Environmentally And Socially Responsible Hotels, Courtney Suess

UNLV Theses, Dissertations, Professional Papers, and Capstones

Development in Southeast Asia involves making good decisions for the future, so the idea that good planning can ignore sustainability is something of an oxymoron. Good development has to be sustainable and we have reached a point where the old ways of tourism development are intolerable. For example, hotels spring up without planning for the future. This short sightedness means natural endowments, like coastlines, erode and forests are cut down, chasing away the wildlife; or cultural history in the form of temples, historic buildings, and sacred places are destroyed. Ironically, tourism development is eradicating the very forms of product that …


Parametric Study Of Efficiency Measures For Home Energy Conservation In Las Vegas, Nevada, Todd M. France Jan 2009

Parametric Study Of Efficiency Measures For Home Energy Conservation In Las Vegas, Nevada, Todd M. France

UNLV Theses, Dissertations, Professional Papers, and Capstones

Pulte Homes, a production home builder and community developer partnering with the U.S. Department of Energy's Building America program, has collaborated with the Center for Energy Research at the University of Nevada, Las Vegas and NV Energy, the local electric utility, on an energy conservation project in the Las Vegas Valley.

This study entails four model homes at a new development in the Summerlin community of Las Vegas, Nevada, named Villa Trieste. The home models, ranging in floor plan area from 1,487 to 1,777 square feet, have been constructed under the Environments for Living program and are LEED (Leadership in …


Water Use And Natural Limits In The Las Vegas Valley: A History Of The Southern Nevada Water Authority, Christian Harrison Jan 2009

Water Use And Natural Limits In The Las Vegas Valley: A History Of The Southern Nevada Water Authority, Christian Harrison

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis examines the history of the Southern Nevada Water Authority (SNWA) and how it has helped transform various aspects of southern Nevada's economy and environment. Prior to the establishment of the SNWA in 1991 the Las Vegas Metropolitan Area (LVMA) possessed several competing water providers whose opposition to one another adversely affected the management of water in the region. These water providers recognized this problem, came together, and negotiated the creation of a regional water agency, the SNWA. This organization, comprised of representatives from each of the LVMA's water providers has the power to institute policy across municipal boundaries. …


Empirically Derived Formulas To Predict Indoor Maximum, Average, And Minimum Temperatures In Roofpond Buildings Using Minimum Climatic Information, Ibrahim Kivarkis Kako Jan 2009

Empirically Derived Formulas To Predict Indoor Maximum, Average, And Minimum Temperatures In Roofpond Buildings Using Minimum Climatic Information, Ibrahim Kivarkis Kako

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis introduces an empirically developed formula to predict the comfort conditions and thermal performance of a Skytherm(TM) Southwest Roofpond placed over a light-weight un-insulated structure built at the School of Architecture at the University of Nevada, Las Vegas.

The predictive formula introduced in this study may be used in different parts of the world (particularly developing nations where insulation and air-conditioning are rarely used) to predict the performance of a Skytherm(TM) Southwest Roofpond using minimal climate data.

The data collected in the experimental setup at the Natural Energies Advanced Technologies Laboratory included outside and inside temperatures of various surfaces …


Two-Tank Indirect Thermal Storage Designs For Solar Parabolic Trough Power Plants, Joseph E. Kopp Jan 2009

Two-Tank Indirect Thermal Storage Designs For Solar Parabolic Trough Power Plants, Joseph E. Kopp

UNLV Theses, Dissertations, Professional Papers, and Capstones

The performance of a solar thermal parabolic trough plant with thermal storage is dependent upon the arrangement of the heat exchangers that ultimately transfer energy from the sun into steam. The steam is utilized in a traditional Rankine cycle power plant. The most commercially accepted thermal storage design is an indirect two-tank molten salt storage system where molten salt interacts with the solar field heat transfer fluid (HTF) through a heat exchanger. The molten salt remains in a closed loop with the HTF and the HTF is the heat source for steam generation. An alternate indirect two tank molten salt …


Bending Of Woody Riparian Vegetation As A Function Of Hydraulic Flow Conditions, John O. Goreham Jan 2009

Bending Of Woody Riparian Vegetation As A Function Of Hydraulic Flow Conditions, John O. Goreham

UNLV Theses, Dissertations, Professional Papers, and Capstones

Vegetation encroachment reduces channel conveyance capacity below design objectives and greatly increases the risk for loss of life and property damage in the case of large flood events. Given minimal knowledge of hydraulic roughness for shrubs and woody vegetation, accurate estimation of channel capacity and water surface elevation is difficult. The ability to predict a tree's bent, reduced height in the presence of flow permits more accurate prediction of hydraulic roughness and water surface elevation.

In this study, field tests were performed to elucidate tree bending properties, which in turn served as input parameters for a numerical algorithm designed to …


Optimization Of Channel Geometry In A Proton Exchange Membrane (Pem) Fuel Cell, Jephanya Kasukurthi Jan 2009

Optimization Of Channel Geometry In A Proton Exchange Membrane (Pem) Fuel Cell, Jephanya Kasukurthi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Bipolar plates are the important components of the PEM fuel cell. The flow distribution inside the bipolar plate should be uniform. Non-uniform flow distribution inside the bipolar leads to poor performance of the fuel cell and wastage of expensive catalyst. A single channel PEM fuel cell is taken and electrochemical analysis is carried out on it. The results are compared with the available published experimental data obtained by other research group, and they are found to be in good agreement. A baseline design of the bipolar plate is taken and numerical analysis is carried out. The results show that the …


Optimization Of Solid Oxide Fuel Cell Interconnect Design, Krishna C. Pulagam Jan 2009

Optimization Of Solid Oxide Fuel Cell Interconnect Design, Krishna C. Pulagam

UNLV Theses, Dissertations, Professional Papers, and Capstones

Performance of solid oxide fuel cells (SOFC) is dependent of a set of complex physical and chemical processes occurring simultaneously. Interconnect for SOFC is important as it provides electrical connection between anode of one individual cell to the cathode of neighboring one. It also acts as a physical barrier to protect the air electrode material from the reducing environment of the fuel on the fuel electrode side, and it equally prevents the fuel electrode material from contacting with oxidizing atmosphere of the oxidant electrode side. A three-dimensional numerical model has been developed to evaluate the SOFC including the current collector, …


Geoelectrical Response Of Surfactant Solutions In A Quartzitic Sand Analog Aquifer, Meghan Therese Magill Jan 2009

Geoelectrical Response Of Surfactant Solutions In A Quartzitic Sand Analog Aquifer, Meghan Therese Magill

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this project, the resistivity and phase shift of ten surfactant aqueous solutions in a sand matrix were measured using spectral induced polarization (SIP). In addition, specific conductivity, pH, dissolved oxygen, and dielectric constant measurements of the solutions were also evaluated. The frequency range assessed was 0.091-12000Hz. The surfactants, which are typically used in the remediation of tetrachloroethylene, were Aerosol MA 80-I, Dowfax 8390, and Steol CS-330. The surfactants were mixed into solutions of both deionized and tap water at varying concentrations and injected into a closed system of silica sand. The surfactant treatments altered resistivity, specific conductivity, and pH …


Experimental And Numerical Study Of A Proton Exchange Membrane Electrolyzer For Hydrogen Production, Sachin S. Deshmukh Jan 2009

Experimental And Numerical Study Of A Proton Exchange Membrane Electrolyzer For Hydrogen Production, Sachin S. Deshmukh

UNLV Theses, Dissertations, Professional Papers, and Capstones

Hydrogen as a fuel source has received attention from researchers globally due to its potential to replace fossil based fuels for energy production. Research is being performed on hydrogen production, storage and utilization methods to make its use economically feasible relative to current energy sources. The PEM electrolyzer is used to produce hydrogen and oxygen using water and electricity. Focus of our study is to provide a benchmark experiment and numerical model of a single cell electrolyzer that can assist in improving the current state of understanding of this system. Parametric analysis of an experimental cell was performed to understand …


Soil Moisture And Water Stage Estimation Using Precipitation Radar, Sumit Puri Jan 2009

Soil Moisture And Water Stage Estimation Using Precipitation Radar, Sumit Puri

UNLV Theses, Dissertations, Professional Papers, and Capstones

In south-western United States, soil moisture data is important for drought studies in the region which is experiencing a drought for many years, whereas in South Florida, water stage data is required by hydrologists to monitor the hydrological flow in wetlands. Soil moisture data and water stage data are not sufficiently available due to sparse monitoring stations. Installation of dense measuring stations over an extended area is costly and labor intensive. Therefore, there is a need to develop an alternative method of measuring soil moisture and water stage. Microwave remote sensing has proven to be a useful tool in the …


An Evaluation Of Lead Hazards In Pre-1978 Residental Housing Within Clark County, Nevada, Usa, Erika Raquel Torres Jan 2009

An Evaluation Of Lead Hazards In Pre-1978 Residental Housing Within Clark County, Nevada, Usa, Erika Raquel Torres

UNLV Theses, Dissertations, Professional Papers, and Capstones

Lead poisoning remains a public health concern due to leads persistence in the environment from anthropogenic uses. Initial efforts to address the impacts of lead on vulnerable communities have included secondary prevention measures which typically occur after a child has been poisoned. However, in recent years there has been a pragmatic shift toward primary prevention efforts.

This study evaluates lead hazards identified through primary prevention activities in residential housing within Clark County, Nevada, USA. It is the first study to systematically address and evaluate pre-1978 housing in Southern Nevada. Risk assessments were conducted in 81 dwellings built prior to 1979 …


Examining The Influence Of Restaurant Green Practices On Customer Return Intention, Audrey L. Szuchnicki Jan 2009

Examining The Influence Of Restaurant Green Practices On Customer Return Intention, Audrey L. Szuchnicki

UNLV Theses, Dissertations, Professional Papers, and Capstones

In recent years there has been an increased awareness of how the actions of the foodservice industry are effecting the environment. With this awareness we have begun to see a change in priorities for both new and existing businesses. At the forefront of this change in the "green" direction is the GRA who certifies how eco-friendly an establishment is based on its' environmental guidelines. This study will examine the correlation between customer return intention and the institution of green practices within a restaurant setting. The expected outcome would be that a restaurant that is certified green or, implementing measures to …