Physical Sciences and Mathematics Commons^™

Design And Preliminary Evaluation Of A Supercritical Carbon Dioxide Brayton Cycle For Solar Dish Concentrator Clean Energy Production, Danielle Nobles-Lookingbill

UNLV Theses, Dissertations, Professional Papers, and Capstones

As we move toward energy independence and more ambitious clean energy goals, solar energy research must push the efficiency limits of traditional energy generation systems. Increases in efficiency can be achieved by increasing the hot temperature of the power cycle. Recent research demonstrates the potential for increased efficiency and a vastly smaller component size when supercritical carbon dioxide Brayton power cycles are used. Concentrated solar and nuclear heat sources are capable of achieving the high working fluid temperatures needed for significant efficiency gains. This NSF EPSCoR funded, experimental research system is designed to exploit the uniquely immense solar irradiance of …

Employee Perceptions Of Organizational Corporate Responsibility And Their Effect On Employee Organizational Commitment, Lisa R. Davis

UNLV Theses, Dissertations, Professional Papers, and Capstones

The debate over whether organizations play a part in society beyond economic profit has been a major focus of research in corporate social responsibility (CSR). These debates have been mainly looked at from the macro (societal) or the meso (institutional) level. Very little research has been done on the role of the firm and looking at CSR from the micro (individual) level. Questions regarding the role of work for employees, securing economic benefits or making a difference in the world, would vary greatly depending on the individual and the importance they place on these areas in their own lives. Scholars …

Influencing Hawai‘I Hotel Patrons To Use Reef-Safe Sunscreens, Rochelle Good

UNLV Theses, Dissertations, Professional Papers, and Capstones

The health of Hawaiian coral reefs is threatened by pollution from common sunscreen ingredients such as oxybenzone. Hawai‘i hotel patrons using sunscreens with harmful ingredients contaminate coral reefs when these products wash off while swimming or bathing. Reef-safe sunscreens are alternative sunscreens that provide effective sun protection while averting damage to coral reefs. The purpose of this research was to determine the dominant factors leading to the pro-environmental behavior of using reef-safe sunscreen and identify practices that Hawai‘i hotel operators could implement to influence patrons to engage in this behavior. This research applied an integrative conceptual framework to model pro-environmental …

Effects Of Ambient Air Pollution On Asthma-Related Emergency Department Visits Within The Las Vegas Metropolitan Area, Loiren E. Monardes

UNLV Theses, Dissertations, Professional Papers, and Capstones

The objective of this research was to evaluate the risk for asthma-related Emergency Department visits and their association with ambient air pollution within the Las Vegas metropolitan area. All data were aggregated by date and ZIP Code. The association was analyzed by applying the distributed lag non-linear model in an attempt to identify elevated concentrations of specific air pollutants

as triggers and their delayed effects (lag days). Relative Risk (RR) and 95% confidence intervals were produced, while adjusting for socioeconomic status. This ecological population-based study analyzed daily asthma counts of Emergency Department visits from January 1st, 2009 to December 31st, …

Human Thermal Comfort In Transition Space, Asawari Anil Pawar

UNLV Theses, Dissertations, Professional Papers, and Capstones

ABSTRACT

HUMAN THERMAL COMFORT IN TRANSITION SPACES

Objective: To evaluate and identify the relationship between personal factors and the climatic conditions that influence the human thermal comfort in transition spaces and suggest solutions for adaptation of the built environment, that would encourage active and healthy living in the tourist as well as local community.

Background:

By 2050, there is a prediction that two-thirds of the world population will be living in urban areas, which would add more than 2.5 billion people living in cities (Melnikov et al., 2017). Since Las Vegas is one of the fastest growing cities in Nevada, …

Prokaryotic Diversity And Aqueous Geochemistry Of Subsurface Environments Of The Death Valley Regional Flow System, Joshua David Sackett

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation summarizes over four years of effort towards the completion of a Ph.D. in Biological Sciences. The work presented in this document covers a broad range of topics, but a central unifying theme is prokaryotic life in the continental subsurface. The work presented in each chapter relied heavily on cultivation-independent methods for assessing prokaryotic communities, including prokaryotic community structure reconstruction from high-throughput sequencing of 16S rRNA gene libraries and single-cell genome analysis of novel uncultivated bacteria.

Chapter 2 examines the aqueous geochemistry and prokaryotic diversity of Devils Hole, a cavernous limnocrene and sole natural habitat for the critically endangered …

The Use Of Chemical Element Fingerprints To Investigate The Transformation Of Lake Sediments To Land Soils In Drying Lakes: A Case Study At Lake Mead, Nevada, Ji Hye Park

UNLV Theses, Dissertations, Professional Papers, and Capstones

Drying lakes are a worldwide catastrophe. The goals of this dissertation research were (1) to investigate whether chemical fingerprints of lake sediments, and nearby land soils, could be established by the analysis of 44 chemical elements, moisture content, Eh, pH, and leachable anions and if so, (2) whether the fingerprints could help explain the process of physical and chemical changes in the lake sediments as they became soils when the lake's water level fell and the anoxic sediments were exposed to the air and weather.

Lake Mead was chosen to model drying lakes because its water level has fallen over …

Examining Environmental Hazards In Rental Homes And Habitability Laws In Clark County, Nevada, Jorge Luis Bertran

UNLV Theses, Dissertations, Professional Papers, and Capstones

It is well established that home conditions are linked to the health outcomes of occupants. There are over 880,000 housing units in Clark County, Nevada; nearly half of those are renter-occupied units (ROUs). Currently, there is limited research on the characteristics of environmental hazards found in Clark County ROUs and the strength of habitability statutes created to protect tenants from substandard housing. Understanding how renters in Clark County are affected by environmental hazards in ROUs and the processes by which landlords and tenants resolve grievances related to those hazards would benefit public health. It would enhance the ability to quickly …

College Of Engineering Senior Design Competition Fall 2018, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge. The senior design competition helps focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects on …

Elevation And Azimuth-Aided Channel Estimation Scheme For Airborne Hyperspectral Data Transmission, Vahid Vahidi, Ebrahim Saberinia

Electrical & Computer Engineering Faculty Research

A channel-estimation (CE) scheme is proposed to estimate the complex amplitude, Doppler shift, angle-of-departure, and angle-of-arrival of the channel taps for sparse and doubly selective channels for hyperspectral image transmission from unmanned aircraft vehicles (UAVs) to ground stations. The proposed method is dubbed as compressed-sensing joint parameter estimation (CS-JPE) and finds the channel parameters matrix by employing a compressed-sensing (CS)-based method. Afterward, a modified version of the joint parameter estimation (JPE) is proposed as CS-JPE and is dubbed as M-CS-JPE, which employs the elevation-azimuth angles of the line-of-sight channel tap to estimate the channel parameters with higher accuracy and lower …

Thing-Makers, Tool Freaks And Prototypers: How The Whole Earth Catalog’S Optimistic Message Reinvented The Environmental Movement In 1968, Andy Kirk

History Faculty Research

In the fall of 1968 a Stanford-trained biologist, organizer of the legendary Trips Festival and Merry Prankster named Stewart Brand published the first Whole Earth Catalog. Between 1968 and 1972, the Catalog reached millions of readers and won the National Book Award. The title and iconic cover image of this counterculture classic celebrated the first publicly released NASA photographs showing the whole planet Earth from space. These images profoundly changed the way humans thought about the environment. And the Catalog played an important role in that change.

A Dramatistic Analysis Of Nevada's Controversy Over Solar Net Metering Incentive Policies, Robert S. Burgy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Utilizing a dramatistic rhetorical lens (Burke, 1945), this project examines Nevada’s 2015-2017 public controversy to decide whether or not to implement solar net metering incentives. By examining communication surrounding The Public Utility Commission of Nevada (PUCN), NV Energy, and SolarCity, this thesis analyzes the underlying social orientations contained within the controversy’s discourse. This thesis examines how the environment was left out of solar energy discourse in favor of economic reasoning. Nevada’s solar controversy is an important component of humanity’s unending conversation about our relationship to the environment and an important case study to develop our understanding of public controversy.

Design Guidelines And Strategies For Thermal Solar Management Of Fenestration In The Desert Climate, David Mccredo

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research evaluates the effects of varying thermal properties of windows in

residential energy use for the moderate altitude and 36'N latitude climate of southern

Nevada, which has a distinct cooling season. A selection of windows across different

shading conditions and total window areas were studied using BEopt energy simulation.

Findings demonstrate that for the specific climate, latitude, and altitude of Las Vegas,

Nevada, the most expensive “high performance” windows are not always the best

option in terms of total site energy use, and can be outperformed by properly shaded

less advanced windows. Under certain conditions, shading was found to …

Hexavalent Chromium Removal From Residual Ion-Exchange Brine Using Ferrous Sulfate, Ana Luiza De Araujo Silva

UNLV Theses, Dissertations, Professional Papers, and Capstones

Removal of hexavalent chromium (Cr(VI)) from water and wastewater is required for health purposes and regulation compliance. Among the technologies available, ion exchange (IX) has been extensively applied and, in most cases, is followed by resin regeneration for the purpose of cost optimization. However, resin regeneration produces residual IX brine, also called waste regenerant brine, which is considered hazardous for containing the contaminant(s) treated in the column. This research focuses on the use of ferrous sulfate (FeSO4) to reduce and precipitate Cr(VI) contained in the regenerant brine from IX resins. The Cr(VI) reduction to trivalent chromium (Cr(III)) occurs due to …

Static And Dynamic Quantitative Microbial Risk Assessment Of Potable Reuse Paradigms, Erfaneh Amoueyan

UNLV Theses, Dissertations, Professional Papers, and Capstones

In recent years, potable reuse applications have become more common due to population growth and increased water demand, especially in communities with limited or variable water resources. However, there are concerns about potential exposure to pathogens and chemical compounds in treated wastewater. Therefore, advanced wastewater treatment processes are of paramount importance in any potable reuse system. The overall aim of this study was to develop and implement static and dynamic QMRAs to compare public health risk in various potable reuse scenarios. Cryptosporidium, norovirus, adenovirus, and Salmonella were chosen as the target pathogens. The research evaluated the performance of full advanced …

Larval-Ant Interactions In The Mojave Desert: Communication Brings Us Together, Alicia Mellor

UNLV Theses, Dissertations, Professional Papers, and Capstones

Butterflies are a diverse and essential group of pollinators whose abundance is predominantly determined by growth and survival of their larvae. In the family Lycaenidae, many species participate in a larval-ant mutualism where ants feed on nutrient-rich nectar produced by larvae and, in turn, protect those larvae from predators. Emerging evidence indicates larval scent in the form of cuticular hydrocarbons (CHCs), not nectar production, drives this interaction. This study takes two approaches to investigate CHCs as the driver behind the larval-ant mutualism in three butterfly species native to southern Nevada: Euphilotes bernardino martini (Martin’s blue), Brephidium exilis (western pygmy blue), …

An Examination Of The Community And Environmental Impact Of A Las Vegas Convention Food Rescue Program, Samantha H. To

UNLV Theses, Dissertations, Professional Papers, and Capstones

Food insecurity affects millions of Americans each year, inflicting negative consequences on the physical and mental health outcomes at all ages. Concurrently, millions of tons of leftover edible foods are sent to landfill each year. Not only does this pose a question of ethics, but increasingly harms the environment by misusing resources and increasing the release of

greenhouse gases.

Food rescue advisory meetings highlighted the need for more focused research to be conducted that assessed the impacts of donating rescued convention food on local environmental and community health. A mixed-method approach was used to detail the food rescue process between …

Management Of An Urban Stormwater System Using Projected Future Scenarios Of Climate Models: A Watershed-Based Modeling Approach, Ranjeet Thakali, Ajay Kalra, Sajjad Ahmad, Kamal Qaiser

Civil and Environmental Engineering and Construction Faculty Research

Anticipating a proper management needs for urban stormwater due to climate change is becoming a critical concern to water resources managers. In an effort to identify best management practices and understand the probable future climate scenarios, this study used high-resolution climate model data in conjunction with advanced statistical methods and computer simulation. Climate model data from the North American Regional Climate Change Assessment Program (NARCCAP) were used to calculate the design storm depths for the Gowan Watershed of Las Vegas Valley, Nevada. The Storm Water Management Model (SWMM), developed by the Environmental Protection Agency (EPA), was used for hydrological modeling. …

Assessing Near Surface Hydrologic Processes And Plant Response Over A 1600 M Mountain Valley Gradient In The Great Basin, Nv, U.S.A., Dale Devitt, Brian Bird, Brad Lyles, Lynn Fenstermaker, Richard Jasoni, Scotty Strachan, Jay Arnone Iii, Franco Biondi, Scott Mensing, Laurel Saito

Life Sciences Faculty Research

This study investigated near surface hydrologic processes and plant response over a 1600 m mountain-valley gradient located in the Great Basin of North America (Nevada, U.S.A.) as part of a long-term climate assessment study. The goal was to assess shifts in precipitation, soil water status and associated drainage with elevation and how this influenced evapotranspiration and plant cover/health estimated by a satellite-derived Normalized Difference Vegetation Index (NDVI), all to better understand how water is partitioned in a mountain valley system. Data were acquired during a three-year period from meteorological stations located in five plant communities ranging in elevation from 1756 …

How Much Water Can We Save By Achieving Renewable Portfolio Standards In The Southwest United States?, Yuzhen Feng, Sachiko Sueki, Dale Devitt, Kumud Acharya

Life Sciences Faculty Research

Electricity in the Southwestern United States is primarily generated with water intensive steam turbines. If energy demand continues to rise this will lead to a further rise in water demand. A comprehensive understanding of water consumption and withdrawal for utility scale generation of electricity is necessary before any improvements in the water efficiency of such systems in arid environments can be made. This study estimated and compared the water usage associated with thermoelectric generation (i.e., natural gas, coal), and solar energy, in the five driest Colorado River Basin states: Utah, New Mexico, Nevada, Arizona, and California. This study also examined …

Integrating System Dynamics And Remote Sensing To Estimate Future Water Usage And Average Surface Runoff In Lagos, Nigeria, Gilles A. Kandissounon, Ajay Karla, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

The goal of this study was twofold; first analyze the patterns of water consumption in Lagos, Nigeria and use them in a System Dynamics (SD) model to make projections about future demand. The second part used remote sensing to quantify the contribution of extensive land use/cover change to urban flooding. Land use/cover dynamics over the past decade was analyzed using satellite imagery provided by Landsat Thematic Mapping (TM). Unsupervised classification was performed with false color composite using the Iterative Self-Organizing Data Analysis (ISODATA) technique in a Geographic Information Systems (GIS). The study area was divided into four different land use …

Safe Drinking Water In The U.S.: A Prediction Of When The Entire U.S. Population Will Have Access To Safe Drinking Water, Blossom Hamika, Haley Merrill, Zoyla Orellana

Math 365 Class Projects

This research is to show when all of the U.S. will have access to safe drinking water.

Nevada Desert Dust With Heavy Metals Suppresses Igm Antibody Production, Deborah E. Keil, Brenda J. Buck, Dirk Goossens, Brett Mclaurin, Lacey Murphy, Mallory Leetham-Spencer, Yuanxin Teng, James E. Pollard, Russell Gerads, Jamie C. Dewitt

Geoscience Faculty Publications

Systemic health effects from exposure to a complex natural dust containing heavy metals from the Nellis Dunes Recreation Area (NDRA) near Las Vegas, NV, were evaluated. Several toxicological parameters were examined following lung exposure to emissive dust from three geologic sediment types heavily used for recreational off-road activities: yellow sand very rich in arsenic (termed CBN 5); a shallow cover of loose dune sand overlying a gravelly subsoil bordering dune fields (termed CBN 6); and brown claystone and siltstone (termed CBN 7). Adult female B6C3F1 mice were exposed by oropharyngeal administration to these three types of geogenic dusts at 0.01–100 …