Engineering Commons^™

Removal Of Disinfection By-Product Precursors Using Magnetic Ion Exchange (Miex(R)): The Effects Of Ph And Source Water Variability, Sarah Cousins

Graduate Theses and Dissertations

Disinfection by-products (DBPs) form as an unintended result of drinking water disinfection, from chemical reactions between disinfectants (e.g., free chlorine) and naturally occurring dissolved organic matter (DOM). At present, 11 DBPs are regulated in treated drinking waters due to potential adverse health effects, including four trihalomethanes (THMs). Despite nearly 40 years of DBP research, compliance with DBP regulations remains a challenge for many drinking water treatment plants (DWTPs), including the four DWTPs located on the Beaver Lake Reservoir in Northwest Arkansas. Due to the high net negative surface charge on DOM, anion exchange is one potentially viable method for removing …

Modeling Passive Solar Distillation Production In Las Vegas, Nevada, Noe I. Santos

UNLV Theses, Dissertations, Professional Papers, and Capstones

A study has been performed to examine the effects of daily weather on the performance of commercial solar distillation basins (solar stills). The objectives of this study were to evaluate the long term performance of solar stills, to instrument two solar stills and record sub-hourly thermal properties, to evaluate existing heat transfer modeling methods for hourly production, and to create new models to predict daily production using experimental distillate production and local weather data by utilizing artificial neural networks, genetic algorithms, and multivariate regression. A system dynamics model was also created to determine the required basin area and storage volume …

Synthesis And Characterization Of Catalysts For The Selective Transformation Of Biomass-Derived Materials, Isaac Tyrone Ghampson

Electronic Theses and Dissertations

The experimental work in this thesis focuses on generating catalysts for two intermediate processes related to the thermal conversion of lignocellulosic biomass: the synthesis and characterization of mesoporous silica supported cobalt catalysts for the Fischer-Tropsch reaction, and an exploration of the reactivity of bulk and supported molybdenum-based nitride catalysts for the hydrodeoxygenation (HDO) of guaiacol, a lignin model compound. The first section of the work details the synthesis of a series of silicasupported cobalt Fischer-Tropsch catalysts with pore diameters ranging from 2-23 nm. Detailed X-ray diffraction measurements were used to determine the composition and particle diameters of the metal fraction, …

Water Quality Trends For Section 319 Priority Watersheds In Northwest Arkansas, 1997-2010, Bryan William Bailey

Graduate Theses and Dissertations

Northwest Arkansas contains two Section 319 Priority Watersheds that the Arkansas Natural Resources Commission (ANRC) has identified as being impacted by point and nonpoint sources of pollution (i.e., phosphorus, nitrogen, and sediment), and the Arkansas Water Resources Center (AWRC) has monitored the water quality at several sites within these watersheds. Water-quality data has been collected over the last decade within the Illinois River Watershed (HUC #11110103) and the Upper White River Basin (Beaver Reservoir HUC# 11010001), each watershed containing three sampling sites. The Illinois River Watershed sites are located on the Illinois River, Osage Creek, and Ballard Creek, and the …

Direct Contact Pyrolysis Of Hydrocarbons: A Source Of Hydrogen And Interesting Carbon Formations, Peter G. Faught

UNLV Theses, Dissertations, Professional Papers, and Capstones

The work detailed in this document looks at a novel liquid metal supported catalytic system for the generation of hydrogen by decomposition of ethanol through direct contact pyrolysis. The hydrogen is produced at relatively low temperatures (500-600°C) and has carbon and water as co-products. It should be noted that CO is not observed as a product at these low temperatures. This is to be contrasted with the hydrogen produced at higher temperature from ethanol which does contain carbon monoxide. The presence of carbon monoxide in hydrogen complicates fuel cell operation and catalytic chemical processes. Thus, the lack of CO in …

Hydroclimatic Forecasting In The Western United States Using Paleoclimate Reconstructions And Data-Driven Models, Christopher Allen Carrier

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis investigated climate variability and their associated hydrologic responses in the western United States. The western United States faces the problem of water scarcity, where the management and mitigation of available water supplies are further complicated by climate variability. Climate variability associated with the phases of oceanic-atmospheric oscillations has been shown to influence streamflow and precipitation, where predictive relationships have led to the possibility of producing long-range forecasts. Based on literature review, four oceanic-atmospheric oscillation indices were identified in having the most prominent influence over the western United States including the El Niño - Southern Oscillation (ENSO), Pacific Decadal …

Energy-Based Analysis Of Utility Scale Hybrid Power Systems, Kwame Agyenim-Boateng

UNLV Theses, Dissertations, Professional Papers, and Capstones

The promise of large-scale use of renewables such as wind and solar for supplying electrical power is tempered by the sources' transient behavior and the impact this would have on the operation of the grid. Among the methods cited for addressing some of those concerns are exploring the complementary nature of solar and wind power generation, and through the use of supplemental energy storage. While the technology for the latter has not been proven to be economical on a large scale at the present time, some assessments of what magnitude is required can be made. An energy-based analysis of utility …

Modeling Of A Novel Solar Down Beam Test Facility Utilizing Newtonian Optics, Ryan J. Hoffmann

UNLV Theses, Dissertations, Professional Papers, and Capstones

As advances in concentrated solar energy progress there will inevitably be an increase in the demand of resources for testing new conceptions. Currently, there are limited facilities available for taking concentrated solar energy concepts from the laboratory bench scale to the engineering test scale. A proposed solution is a scientific and developmental facility that provides highly concentrated solar energy at ground level. The design presented is a solar down beam test facility utilizing a Newtonian optics approach with a flat rectangular down beam mirror to reflect and concentrate the sun's rays at ground level.

Literature review suggests a hyperbolic reflector …

Fenestration Studies On Building Energy Using The Facade Evaluation Facility, Wendell Cocina

UNLV Theses, Dissertations, Professional Papers, and Capstones

The project was developed to assess several types of facades and their influence on building energy, mainly focused on windows and other building fenestrations. Requirements for the facility are stated in this paper alongside corresponding solutions. The facility is designed to represent a section of a building façade. Experimenting on a wide range of fenestrations including windows with integrated PV elements was the primary prerequisite. The option of removable façade configurations was used and allowed testing specimens to be changed effortlessly. Instrumentation and data acquisition are discussed including calibration and uncertainty analysis. Investigation of the air conditioning unit was concluded …

Morphology Changes In Pcpdtbt:Pcbm And P3ht:Pcpdtbt:Pcbm And Its Effect On Polymer Solar Cell Performance, Galen David Cauble

Physics

Polymer solar cell morphology is sensitive to both heat and time. By thermally annealing polymer solar cells the morphology of the devices can be altered causing immediate changes in device performance. Blending PCPDTBT:PCBM with P3HT:PCPDTBT combines the absorption characteristics of each to create a more even absorption spectrum. Subjecting PCPDTBT:PCBM, and P3HT:PCPDTBT:PCBM polymer solar cells to thermal annealing as well as recording device performance through time has shown that P3HT:PCPDTBT:PCBM devices react positively to thermal annealing (increasing from 0.8% to 1.4%) while PCPDTBT:PCBM devices have varied reactions. Furthermore, the P3HT:PCPDTBT:PCBM devices have achieved efficiencies of 1.6% in AM 1.5 compared …

Time-Dependent Crack Growth Behavior Of Alloy 617 And Alloy 230 At Elevated Temperatures, Shawoon Kumar Roy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Two Ni-base solid-solution-strengthened superalloys: INCONEL 617 and HAYNES 230 were studied to check sustained loading crack growth (SLCG) behavior at elevated temperatures appropriate for Next Generation Nuclear Plant (NGNP) applictaions with constant stress intensity factor (K _max = 27.75 MPa[checkmark]m) in air. The results indicate a time-dependent rate controlling process which can be characterized by a linear elastic fracture mechanics (LEFM) parameter - stress intensity factor (K). At elevated temperatures, the crack growth mechanism was best described using a damage zone concept. Based on results and study, SAGBOE (stress accelerated grain boundary oxidation embrittlement) is considered the primary reason for …

Groundwater Contamination Potential In Northern Nevada From Mining, Associated Communities, And Agriculture As Forecasted By Two Vulnerability Methods, John L. Swatzell

UNLV Theses, Dissertations, Professional Papers, and Capstones

Two methodologies, DRASTIC and the NDEP method, were used to compare the groundwater vulnerability of mining, associated towns, and agricultural areas in northern Nevada. The DRASTIC and NDEP methods were compared to determine which method produces a more accurate depiction of vulnerability. Vulnerability maps were created using the United States Environmental Protection Agency's (USEPA) DRASTIC and Nevada Department of Environmental Protection (NDEP) methodologies. The DRASTIC map uses seven aspect layers of geologic and hydrologic information with assigned values and weights that are applied to a mathematical equation. The NDEP method uses field data collection for potential contaminant sources and well …

Improving The Efficiency Of Organic Solar Cells By Varying The Material Concentration In The Photoactive Layer, Kevin Anthony Latimer

Electrical & Computer Engineering Theses & Dissertations

Polymer-fullerene bulk heterojunction solar cells have been a rapidly improving technology over the past decade. To further improve the relatively low energy conversion efficiencies of these solar cells, several modifications need to be made to the overall device structure. Emerging technologies include cells that are fabricated with interfacial layers to facilitate charge transport, and tandem structures are being introduced to harness the absorption spectrum of polymers with varying bandgap energies.

When new structures are implemented, each layer of the cell must be optimized in order for the entire device to function efficiently. The most volatile layer of these devices is …

Groundwater Research In Middle Earth, Thomas Lapoint

Liberal Arts and Engineering Studies

My senior project focused on studying saltwater intrusion in a coastal town of New Zealand. I feel lucky that I was able to travel to such a distant place, conduct research that was insightful and interesting, and immerse myself in an international culture all in the name of my education. As a Liberal Arts and Engineering Studies student, I aim to analyze not only the cultural differences and similarities that the foreign environment offers to me but also the detailed, technical, engineering aspect of my research. I believe that my education should be approached with a well rounded perspective that …

Manual Rubber Sandal Press For Loisaba Kenya, Bridget N. Little

Honors Theses

The goal of this project was to develop an inexpensive manual cutting machine to cut sandals out of recycled tires and industrial belt allowing poor Kenya villages to produce their own sandals that are durable enough to survive the rough terrain. In Kenya 56 percent of the population live in poverty, surviving on less than a dollar a day. Walking is the main mode of transportation and the majority of Kenyans can only afford second hand shoes that wear out easily on the unpaved roads. In developing this machine the goal was to make the machine affordable for a company …

An Environmental Economic Analysis Of Green Building And The Leadership In Energy And Environmental Design Rating System, John A. Manna

Honors Theses

Buildings account for over 70% of U.S. energy consumption and produce 30% of the nation’s greenhouse gas emissions. With growing concerns over future energy prices, the green building industry and the LEED rating system have made it their goal to produce better performing, more efficient buildings. LEED projects have been implemented in all 50 states, with 46 implementing LEED into public policy. In this study we evaluate the environmental and economic benefits of the LEED certification process. A cost-benefit analysis provides a framework for assessing the life cycle of a LEED building, incorporating both energy and cost savings, as well …

Improving The Energy Efficiency Of Fero House Home Of Alpha Delta Phi, Matt S. Stankiewicz

Honors Theses

As our country continues to grow and prosper we are faced with a growing number of environmental issues. While many of these issues were ignored in the pursuit of economic growth, we are now facing the harsh realities of our unmitigated expansion. The continual mining and use of fossil fuels has scarred our landscapes, polluted our air, and contaminated our waterways. Our nation’s greenhouse gas emissions are higher than ever and contributing heavily to global warming. With the United States’ population constantly on the rise and projected to hit 350 million in little over a decade1, it appears that our …

Characterization Of Green Roofs And Their Potential Effects On The Union College Campus, Cybil Tribie

Honors Theses

A green roof is the construction of protective layers and vegetation on the roof of a building. Green roofs are capable of providing ecological benefits to the environment as well as economic advantages for the client. Therefore, my thesis will explore the characterization features of green roofs by focusing on the layers they are made up of, the different types of green roofs, and the benefits they can provide. Although this technology is relatively new to the United States in comparison to places such as Germany, where green roofs have been extensively used for over 40 years, there is a …

Uncertainty Estimation Of Extreme Precipitations Under Climate Change: A Non-Parametric Approach, Tarana A. Solaiman

Electronic Thesis and Dissertation Repository

Assessment of climate change impacts on hydrology at watershed scale incorporates (a) downscaling of global scale climatic variables into local scale hydrologic variables and (b) assessment of future hydrologic extremes. Atmosphere-Ocean Global Climate Models (AOGCM) are designed to simulate time series of future climate responses accounting for human induced green house gas emissions. The present study addresses the following limitations of climate change impact research: (i) limited availability of observed historical information; (ii) limited research on the detection of changes in hydrologic extremes; and (iii) coarse spatio-temporal resolution of AOGCMs for use at regional or local scale. Downscaled output from …

The Transfer Of Agricultural Water To Municipal And Industrial Usages, Dallin Paul Stephens

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The water that is available for beneficial use in Utah is quickly approaching full appropriation; water that has been claimed is nearing the amount that is available for use. The Division of Water Resources of the State of Utah has organized a three-part plan to "Plan, Conserve, Develop and Protect Utah's Water Resources." One of these three elements has a focus to "provide comprehensive water planning." Such planning is best achieved when current and accurate data on the uses of the state's water are available.

The primary purpose of this thesis was to provide an evaluation, from data collected on …

Association Of Oceanic-Atmospheric Oscillations And Hydroclimatic Variables In The Colorado River Basin, Ajay Kalra

UNLV Theses, Dissertations, Professional Papers, and Capstones

With increasing evidence of climatic variability, there is a need to improve forecast for hydroclimatic variables i.e., precipitation and streamflow preserving their spatial and temporal variability. Climatologists have identified different oceanic-atmospheric oscillations that seem to influence the behavior of these variables and in turn can be used to extend the forecast lead time. In the absence of a good physical understanding of the linkages between oceanic-atmospheric oscillations and hydrological processes, it is difficult to construct a physical model. An attractive alternative to physically based models are the Artificial Intelligence (AI) type models, also referred to as machine learning or data-driven …

Computational Study Of Passive Neutron Albedo Reactivity (Pnar) Measurement With Fission Chambers, Sandra De La Cruz

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Passive Neutron Albedo Reactivity technique (PNAR) was used to assay used nuclear fuel as a potential method for the measurement of fissionable material in fuel assemblies. A Monte Carlo transport code (MCNPX 2.6) was used to develop simulation models to evaluate the PNAR technique. The MCNPX simulated models consisted of two 17x17 Pressurized Water Reactor (PWR) used fuel assemblies; one with an initial 3 wt% uranium-235*, cooled for 20 years and second with an initial 4 wt% uranium-235*, cooled for 5 years. Each used fuel assembly was simulated at four different burn up rates of 15, 30, 45, and …

An Empirical Comparison Of Life Cycle Cost Of Green School Buildings And Non-Green School Buildings, Nitisha Pushpala

UNLV Theses, Dissertations, Professional Papers, and Capstones

One of the major economic concerns today of the world is reduction of energy consumption because of depleting energy sources in the world. The construction sector in the United States is also contributing in reducing the energy consumption and construction cost of the buildings by constructing cost and energy efficient buildings with energy efficient materials and techniques. The U.S Department of Energy introduced the Building Technologies Program that develops techniques, tools and technologies for making buildings more energy efficient. Other private bodies like the Leadership in Energy and Environmental Design (LEED), which is developed by the U.S. Green Building Council …

Impacts Of Climate Change And Weather Modification On Hydrologic Characteristics Of Watersheds In The Western United States, Anil Acharya

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research quantifies the impacts of climate change and weather modification (WM) on hydrologic characteristics of watersheds in the arid regions of the western United States. This research performs a long-term simulation of streamflow for present and future climate conditions in the North Platte (NP) Watershed, Wyoming; a shorter duration simulation is then performed to observe the likely impacts of event based changes in an urban watershed in Las Vegas, Nevada.

First, a study is carried out in Chapter 3 that evaluates the impacts of WM on water supply by developing a hydrologic model for the NP Watershed. The variable …

Piano Key Weir Head Discharge Relationships, Ricky M. Anderson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A piano key (PK) weir is a type of nonlinear (labyrinth-type) weir developed specifically for free-surface flow control structures with relatively small spillway footprints. Currently, no generally accepted standard PK weir design procedure is available. This is due, in part, to the large number of geometric parameters and a limited understanding of their effects on discharge efficiency (discharge efficiency is quantified by the discharge coefficient of the standard weir equation). However, Hydrocoop, a non-profit French dam spillways association, has recommended a PK weir design and a head-discharge relationship specific to that geometry.

To develop a better understanding of the effects …

Innovative Pollutant Load Monitoring, Eric Gurr

Electronic Theses and Dissertations

Modern streamflow measuring equipment, water quality sampling techniques and a better understanding of pollutant washoff are continuously being developed as today's society is in critical need of improving water management, minimizing developmental impacts and preventing environmental hazards. In particular, the study of the spatial, temporal and volumetric characteristics of annual pollutant loading caused by variations in precipitation, land use and other anthropogenic factors is of great significance due to their relation to future global water demands. The research presented here falls in three parts. In the first part of the dissertation, an acoustical Doppler velocity profiler installed in a submerged …

Investigation On Flame Characteristics Of Oxy-Fuel Combustion, Md R. Islam

Open Access Theses & Dissertations

Oxy-fuel combustion is currently being considered by the U.S Department of Energy as a promising technology for efficient carbon capture. This technology could substantially reduce NOx and CO2 emissions. In addition, the implementation of oxy-fuel combustion technology in a power generation system could potentially reduce negative environmental impacts of fossil fuel use. It also encourages the use of reliable and domestic energy sources. The U.S. Department of Energy has made efforts to investigate the performance of a CO2 and H2O diluted oxy-fuel combustion system in a high-pressure combustor. In an effort to better understand and characterize the fundamental flame characteristics …

Adaptation Of Low Impact Design To The Desert Southwest, Abubaker Ali Alamailes

Open Access Theses & Dissertations

A low Impact Development (LID) practices were used to design an Integrated Management Practices (IMP) system for a residential lot .The design was adapted to the Desert Southwest region based on twenty years of climate data including precipitation and temperature for three representative cities: El Paso, TX, Albuquerque, NM, and Phoenix, AZ. In order to capture stormwater runoff close to its source and to provide as much stored water as possible for plants, LID practices including bioretention cells and vegetated swales were applied throughout the lawn. The purpose of the design is to maintain the pre-development hydrologic characteristics of the …

Analysis Of Endocrine Disrupting Compounds In Wastewater Treatment Plants: A Perspective Of Trans-Boundary Waterborne Pollution, Roberto De La Torre

Open Access Theses & Dissertations

Recent decades have brought an increasing concern of potential adverse human and ecological health effects resulting from Endocrine Disruptor Compounds (EDCs). In particular from new emerging compounds such as natural estrogens (e.g., 17©¬-estradiol, estrone), synthetic estrogens (e.g., 17Â¥á-ethynylestradiol), bisphenol A (BPA), nonylphenol ethoxylates (NPEOS), and nonylphenol (NP). These chemicals which are also known as organic wastewater contaminants are released directly to the environment after passing through wastewater treatment plants (WWTPs), which often are not designed to remove them from the effluent. The occurrence of the aforementioned compounds in surface water is becoming of increasing concern worldwide, and has led to …

Assessment Of Intra-Urban Traffic-Related Air Pollution On Asthmatic Children's Exposure At Schools In The Paso Del Norte Region, Amit Ugamraj Raysoni

Open Access Theses & Dissertations

Traffic-related air pollution can be a major public health concern in any urban area. This problem is compounded in the Paso del Norte region that has experienced rapid economic growth, and a substantial number of people living in close vicinity of major roadways. The desert surroundings, arid weather, frequent temperature inversions, heavy border traffic at the international ports of entry between El Paso and Ciudad Juárez, and poorly maintained vehicle fleet further exacerbates this problem. A growing body of air quality and epidemiologic research has discerned the linkage between traffic emissions and respiratory disorders.

Initial health investigations in the Paso …