Engineering Commons^™

Cost-Effective Recovery Of Concentrated Cooling Tower Blowdown Using The Cerro Process, Lindsey Nicole Larson

Open Access Theses & Dissertations

The Concentrate Enhanced Recovery Reverse Osmosis (CERRO) process is a seawater-RO unit that can cost-effectively achieve extremely high recoveries from water high in silica, carbonate and sulfate concentrations. This relatively new technology takes advantage of the induction time of potential foulants to recover more water than what is normally achievable with a conventional desalination system. The scope of the project was to evaluate the efficiency of the CERRO process as a pilot study using cooling tower blowdown which varied in water quality parameters daily. It was found that the CERRO pilot could successfully achieve 85% recovery, and the main limitation …

The Former Asarco Demolition Fallout, A Post Study On Lead Soil Concentrations And Environmental Agents Of Redistribution In El Paso, Texas, Stephanie A. Robinson

Open Access Theses & Dissertations

The former El Paso ASARCO Smelting and Refining Co. operated between 1877 and 1999, the pyrometallurgic activity was estimated to have discharged excess of a 1,000 tons of lead (Pb) into the atmosphere from 1969-71. It was estimated 96 tons of (Pb) were emitted on an annual basis from the standing ore and fluid beds. The Environmental Protection Agency (EPA) determined that lead (Pb) is the heavy metal of the highest concentration within the vicinity of the smelter. After the smelter production ceased, flash flooding common to the southwest, such as the 2006 historic flood, increased transportation of superficial contaminants …

Pyroelectric Ceramics As Temperature Sensors For Energy System Applications, Jorge Luis Silva

Open Access Theses & Dissertations

Temperature is continuously monitored in energy systems to ensure safe operation temperatures, increase efficiency and avoid high emissions. Most of energy systems operate at high temperature and harsh environments to achieve higher efficiencies, therefore temperature sensing devices that can operate under these conditions are highly desired. The interest has increased in temperature sensors capable to operate and in harsh environments and temperature sensors capable to transmit thermal information wirelessly. One of the solutions for developing harsh environment sensors is to use ceramic materials, especially functional ceramics such as pyroelectrics. Pyroelectric ceramics could be used to develop active sensors for both …

Renewable Energy Systems Optimization Using Monte Carlo Simulation And Evolutionary Algorithms, Nicolas Lopez

Open Access Theses & Dissertations

This Dissertation explores the Renewable Energy Integration Problem, and proposes a Genetic Algorithm embedded with a Monte Carlo simulation to solve large instances of the problem that are impractical to solve via full enumeration. The Renewable Energy Integration Problem is defined as finding the optimum set of components to supply the electric demand to a hybrid

microgrid. The components considered are solar panels, wind turbines, diesel generators, electric batteries, connections to the power grid and converters, which can be inverters and/or rectifiers. The methodology developed is explained as well as the combinatorial formulation. In addition, 2 case studies of a …

Ab Initio Study Of The Effects Of Humidity On Perovskite Based Hybrid Solar Cell Interfaces, Shantanu Rajendra Rachalwar

Browse all Theses and Dissertations

Despite the impressive success of perovskite-based hybrid solar cells, their widespread usage has been limited partially owing to stability issues under working environmental conditions. Among these, the effects of humidity are some of the most significant. Water intercalation generally degrades the material, shortens its useful life, and reduces the efficiency of photovoltaic energy conversion. Understanding the reasons for these effects can be achieved through detailed and accurate atomic-scale analysis. Here, we study water intercalation at the interfaces of perovskite-based hybrid solar cell material and TiO2 electrode. Accurate ab initio computer simulations are used to obtain structural and electronic properties. We …

What Green Design Activities And Mindsets Drive Innovation And Sustainability In Student Teams?, Jeremy Faludi, Alice Agogino, Sara Beckman, Alastair Isles

Dartmouth Scholarship

What sustainable design practices can also drive innovation, and what practices do people value? Previous analysis of sustainable design methods, and the opportunism of designers generally, has suggested that design methods should actually be examined at the level of their component activities and mindsets, as each of these provides different advantages that designers could mix and match. This study performed workshops of three sustainable design methods for a total of 327 students, then surveyed students about which activities or mindsets within each design method drove innovation value, sustainability value, and any other value. The design methods tested were The Natural …

Study Of Periodical Flow Heat Transfer In An Internal Combustion Engine, Xi Luo

Wayne State University Dissertations

In-cylinder heat transfer is one of the most critical physical behaviors which has a direct influence on engine out emission and thermal efficiency for IC engine. In-cylinder wall temperature has to be precisely controlled to achieve high efficiency and low emission. However, this cannot be done without knowing gas-to-wall heat flux. This study reports on the development of a technique suitable for engine in-cylinder surface temperature measurement, as the traditional method is “hard to reach.” A laser induced phosphorescence technique was used to study in-cylinder wall temperature effects on engine out unburned hydrocarbons during the engine transitional period (warm up). …

Studies Of Air Pollutants And Their Impact On Respiratory And Cardiovascular Diseases In The El Paso Del Norte Region With Emphasis On Mobile Emissions, Juan Gustavo Arias Ugarte

Open Access Theses & Dissertations

Air pollution may cause different diseases, such as cardiovascular and lung diseases. Traffic is a major source of mobile emissions causing air pollution. Exhaust emissions from mobile sources (Emissions of Carbon Monoxide, Nitrogen Oxides and Hydrocarbons) and Non-exhaust (Brake and Tire) are complex mixtures of gases and dust, including a large number of ultrafine particles, especially in areas with high traffic density. Recent studies have shown high rates of morbidity and mortality in people exposed to these types of emissions because the fine and ultrafine particles can be transported from the respiratory airways to the organs, thus contributing to increase …

Structure Stability And Optical Response Of Lead Halide Hybrid Perovskite Photovoltaic Materials: A First-Principles Simulation Study, Siddharth Narendrakumar Rathod

Browse all Theses and Dissertations

A third-generation of solar cell is based on organic-inorganic hybrid perovskite materials. These have reached up to 22.1% conversion efficiency through exponential growth just within the last decade, compared to much longer improvement times for other photovoltaic technologies. Lead halide perovskites are among the most commonly used materials in this context. Despite the relatively large number of available works on some of these materials, in particular CH3NH3PbI3, others are less investigated. Here, we focused on CH3NH3PbCl3, CH3NH3PbBr3 and CH3NH3PbI3 for assessing structure stability and optical response. Using quantum-mechanics-based first principles approaches, we calculated the optimized structures of these three materials …

Mathematical Modeling Of A P-N Junction Solar Cell Using The Transport Equations, Surjeet Singh

Browse all Theses and Dissertations

While analytical models are limited in the situations that they can simulate, they are generally easier to implement than numerical models and provide a rapid view of the variables which affect a certain quantity. Analytical models are also very useful in educational situations; such as a graduate class on photovoltaics. The modeling of the interior workings of a solar cell can be complex and involved; and some of the equations can become quite lengthy. A focus of this thesis work is the derivation of the minority carrier density and minority current density equations for a p-n junction solar cell. The …

Configuration And Electronic Properties Of The Interface Between Lead Iodide Hybrid Perovskite And Self-Assembled Monolayers In Solar Cells, Parin Divya Amlani

Browse all Theses and Dissertations

Hybrid perovskite photovoltaic materials are currently the most promising functional materials for solar cell applications with efficiency reaching to those of more conventional materials such as silicon. Using self-assembled monolayers between photovoltaic materials and electrodes is a method for improving the stability and functionality. Recent experiments have shown that using 4-mercaptobenzoic acid and pentafluorobenzenethiol monolayers bridging lead iodide hybrid perovskite photovoltaic materials and electrodes result in improved stability and efficiency. The details of monolayer assembly, molecular adsorption configuration, and resulting modification of electronic properties are important characteristics related to solar cell performance. These characteristics can be obtained through accurate computer …

Resilience In Ecotoxicology: Toward A Multiple Equilibrium Concept, Mirco Bundschuh, Ralf Schulz, Ralf B. Schäfer, Craig R. Allen, David G. Angeler

School of Natural Resources: Faculty Publications

The term resilience describes stress-response patterns across scientific disciplines. In ecology, advances have been made to clearly define resilience based on underlying mechanistic assumptions. Engineering resilience (rebound) is used to describe the ability of organisms to recover from adverse conditions (disturbances), which is termed the rate of recovery. By contrast, the ecological resilience definition considers a systemic change, that is, when ecosystems reorganize into a new regime following disturbance. Under this new regime, structural and functional aspects change considerably relative to the previous regime, without recovery. In this context, resilience is an emergent property of complex systems. In the present …

Recommending Sustainable Design Practices By Characterizing Activities And Mindsets, Jeremy Faludi

Dartmouth Scholarship

How do designers, engineers, and managers choose the best sustainable design method for their work? How can different design practices combine to complement each other? This study makes recommendations by deconstructing 14 design methods, guides, certifications, and other practices into their constituent activities and mindsets, then characterizing those activities and mindsets. For example, some of the seven activity categories are analysis, ideation, and goal-setting; some of the eight mindset categories are priorities, abstract versus concrete goals, and environmental versus social goals. Recommendations are given for matching sustainable design practices to different usage contexts by their constituent activities and mindsets. It …

Smart Home Energy Management: An Analysis Of A Novel Dynamic Pricing And Demand Response Aware Control Algorithm For Households With Distributed Renewable Energy Generation And Storage, Jamal Abushnaf

Theses: Doctorates and Masters

Home energy management systems (HEMS) technology can provide a smart and efficient way of optimising energy usage in residential buildings. One of the main goals of the Smart Grid is to achieve Demand Response (DR) by increasing end users’ participation in decision making and increasing the level of awareness that will lead them to manage their energy consumption in an efficient way. This research presents an intelligent HEMS algorithm that manages and controls a range of household appliances with different demand response (DR) limits in an automated way without requiring consumer intervention. In addition, a novel Multiple Users and Load …

Development Of Disaster Management In Turkey: From 1999 Kocaeli Earthquake To 2011 Van Earthquake, Mert Tolon, Kağan Cenk Mızrak

Civil Engineering Faculty Publications

The natural disasters that have occurred in Turkey are categorized as % 61 earthquakes, followed by landslides, floods, rock falls, fires and storms. Between the years of 1903 and 2000, there have been nearly 150 earthquakes in Turkey which led to damage and this is a challenge for Turkey. The management and plans of these natural disasters in Turkey were first developed in 1959. In 1999, with the magnitude of 7.4, The Kocaeli and Duzce earthquakes affected a region of Turkey that constitutes % 23 of the country’s population. After that, in 2000 necessary laws have been prepared and enacted. …

Modeling Dynamic Community Acceptance Of Mining Using Agent-Based Modeling, Mark Kofi Boateng

Doctoral Dissertations

"This research attempts to provide fundamental understanding into the relationship between perceived sustainability of mineral projects and community acceptance. The main objective is to apply agent-based modeling (ABM) and discrete choice modeling to understand changes in community acceptance over time due to changes in community demographics and perceptions. This objective focuses on: 1) formulating agent utility functions for ABM, based on discrete choice theory; 2) applying ABM to account for the effect of information diffusion on community acceptance; and 3) explaining the relationship between initial conditions, topology, and rate of interactions, on one hand, and community acceptance on the other …

Characterization Of Ecological Water Stress In The U.S. Great Lakes Region Using A Geospatial Modeling Approach, Sara Alian

Dissertations, Master's Theses and Master's Reports

Anthropocentric water resources management affects aquatic habitats by changing streamflow regime. Understanding the impacts of water withdrawal from different sources and consumption by various economic sectors at different spatial and temporal scales is key to characterizing ecologically harmful streamflow disturbances. To this end, we developed a generic, integrative framework to characterize catchment scale water stress at annual and monthly time scales. The framework accounts for spatially cumulative consumptive and non-consumptive use impacts and associated changes in flow due to depletion and return flow along the stream network. Application of the framework to the U.S. Great Lakes Region indicates that a …

Heavy Metal Distribution And Groundwater Quality Assessment For A Coastal Area On A Chinese Island, Sha Lou, Shuguang Liu, Chaomeng Dai, An Tao, Bo Tan, Gangfeng Ma, Roman Sergeeyvich Chalov, Sergey Romanovich Chalov

Civil & Environmental Engineering Faculty Publications

Chongming Island is located in the lower Yangtze Estuary in China. Due to the Leachate from a refuse landfill and the hydrodynamics of the Yangtze Estuary, the groundwater environment is particularly complicated on Chongming Island. Field observations were carried out around the landfill disposal site. The groundwater table, temperature, pH, salinity, and dissolved oxygen were measured in the field by portable equipment, and 192 water samples were collected at eight groundwater sites and one surface water site. Through laboratory analysis we found the highest measured concentration of Cr to be 54.07 μg/L, and the measured concentration of Zn was in …

Spatiotemporal Distribution Of Eutrophication In Lake Tai As Affected By Wind, Wenhui Zhang, Qiujin Xu, Xixi Wang, Xiaozhen Hu, Cheng Wang, Yan Pang, Yanbin Hu, Yang Zhao, Xiao Zhao

Civil & Environmental Engineering Faculty Publications

One common hypothesis is that wind can affect concentrations of nutrients (i.e., nitrogen and phosphorus) and chlorophyll-a (Chl-a) in shallow lakes. However, the tests of this hypothesis have yet to be conclusive in existing literature. The objective of this study was to use long-term data to examine how wind direction and wind speed affect the spatiotemporal variations of total nitrogen (TN), total phosphorus (TP) and Chl-a in Lake Tai, a typical shallow lake located in east China. The results indicated that the concentrations of nutrients and Chl-a tended to decrease from the northwest to the southeast of Lake Tai, with …

College Of Engineering Senior Design Competition Fall 2016, 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 …

Characterization And Delineation Of Karst Geohazards Along Rm652 Using Electrical Resistivity Tomography, Culberson County, Texas, Adam F. Majzoub

Electronic Theses and Dissertations

The Delaware Basin of West Texas and southeastern New Mexico is the major western subdivision of the Permian Basin and a northern extension of the Chihuahuan Desert. The major evaporite unit within the Delaware Basin is the Castile Formation, which consists of gypsum/anhydrite and is highly susceptible to dissolution and karsting. Manifestations of karst within the Castile outcrop are abundant and include sinkholes, subsidence features and caves, both epigene and hypogene in origin.

Land reconnaissance surveys conducted during the summer of 2015 documented abundant karst landforms in close proximity to a major thoroughfare, RM 652, in Culberson County, Texas. 2D …

Policy Design Tool For Managing Indoor Residential Water Demand In Water-Scarce Regions, Mujahed M. Thneibat

Open Access Dissertations

In view of population growth; climate change; and economic evolution, water resources in numerous parts of the world have reached their natural capacities. Consequently, the ability of many countries to grow; meet the basic needs of inhabitants; and protect the environment will be endangered like never before unless water resources are smartly handled and managed. ^ In the past few decades, many developed and developing countries have suffered from water scarcity, and more are certain to follow. The water security dilemma is much more challenging in developing countries. Water utilities have had to follow regulatory plans to manage demand on …

Overseas Chinese Environmental Engineers And Scientists Association (Oceesa) Report, Dec 2016., Yung-Tse Hung, Wen-Chi Ku, Lawrence K. Wang

Civil and Environmental Engineering Faculty Publications

This Overseas Chinese Environmental Engineers and Scientists Association (OCEESA) report is 2016 Directory of Overseas Chinese Environmental Engineers and Scientists Association (OCEESA), Report number: OCEESA/JL-2016/33D1, December 2016, ISSN 1072 -7248. This report was prepared by Yung-Tse Hung, Permanent Executive Director, OCEESA. This report includes OCEESA contact information, list of OCEESA Directors, list of OCEESA past presidents, OCEESA membership data, constitutions and by laws of OCEESA (5 November 2000 edition), constitutions and by laws of OCEESA (14 February 2006 edition), constitutions and by laws of OCEESA (27 October 2013 edition), membership application form, letter from Wen-Chi Ku to confirm Yung-Tse Hung …

Stationary Nonimaging Concentrators – A Comprehensive Study And Design Improvements, Srikanth Madala

UNLV Theses, Dissertations, Professional Papers, and Capstones

Most places on our planet receive an annual average radiation between 800-1000 W/m2. In the man-made world, this radiation is largely incident on stationary structures such as buildings, roads, monuments, bridges etc. Moreover, in the natural world also, there are large tracts of barren land which can be put to good use given their solar energy potential. The vision of the current research is to concentrate all this available solar energy to a more readily usable form. Therefore, stationary nonimaging solar concentrator technologies are sought after. This dissertation work is an exhaustive research on the nonimaging concentrating mechanisms with stationary …

Field Emissions Of (Hydro)Chlorofluorocarbons And Methane From A California Landfill, Alexander H. Sohn

Master's Theses

A comprehensive field investigation was conducted at Potrero Hills Landfill (PHL) located in Suisun City, California to quantify emissions of twelve (hydro)chlorofluorocarbons (i.e. F-gases). The specific target constituents for this study included CFC-11, CFC-12, CFC-113, CFC-114, HCFC-21, HCFC-22, HCFC-141b, HCFC-142b, HCFC-151a, HFC-134a, HFC-152a, and HFC-245fa. The majority of the F-gas emission studies have been conducted outside of the United States and very limited field landfill emission data are available in the United States. Because of historical usage of blowing agents in insulation foams including CFC-11, HCFC-142b, HFC-134a, and HFC-245fa, models reported in literature predicted high F-gas emissions from a landfill …

Spatial Distribution Of Antibiotic Resistance In Soils Receiving Beef Feedlot Runoff, Scott Speicher

Department of Environmental Engineering: Theses and Other Student Research

A study was conducted to provide new insight on the potential contribution to antibiotic resistance from the land application of beef feedlot runoff to soil. This study reports the distribution and quantity of antibiotic resistant bacteria (ARBs), fecal indicator bacteria (FIB), and antibiotic resistance genes (ARGs) in soil from (i) a field receiving long-term application of beef feedlot runoff holding pond effluent and (ii) a cool-season pasture with no history of supplemental manure application.

Soil samples were collected June 2015 at the U.S. Meat Animal Research Center near Clay Center, Nebraska. A response surface sampling design (RSSD) model based on …

Ncer Assistance Agreement Annual Progress Report For Grant #83582401 - Assessment Of Stormwater Harvesting Via Manage Aquifer Recharge (Mar) To Develop New Water Supplies In The Arid West: The Salt Lake Valley Example, Ryan Dupont, Joan E. Mclean, Richard C. Peralta, Sarah E. Null, Douglas B. Jackson-Smith

Civil and Environmental Engineering Faculty Publications

The aims of the original proposed project remain the same, that is, to test the hypothesis that Managed Aquifer Recharge (MAR) for stormwater harvesting is a technically feasible, socially and environmentally acceptable, economically viable, and permittable option for developing new water supplies for arid Western urban ecosystems experiencing increasing population, and climate change pressures on existing water resources. The project is being carried out via three distinct but integrated components that include: 1) Monitoring of existing distributed Managed Aquifer Recharge (MAR) harvesting schemes involving a growing number of demonstration Green Infrastructure (GI) test sites; 2) Integrated stormwater/vadose zone/groundwater/ ecosystem services …

Diversity And Impacts Of Mining On The Non-Volant Small Mammal Communities Of Two Vegetation Types In The Brazilian Amazon, Natália Carneiro Ardente, Átilla Colombo Ferreguetti, Donald Gettinger, Pricila Leal, Ana Cristina Mendes-Oliveira, Fernanda Martins-Hatano, Helena Godoy Bergallo

Harold W. Manter Laboratory of Parasitology: Faculty Publications

The CarajaÂs National Forest contains some of the largest iron ore deposits in the world. The majority of the minerals are found below a plant community known as Savana Metalo fila, or ªCangaº, which represents only 3% of the landscape within the CarajaÂs National Forest (CNF). The aim of our study was to understand the diversity of community of non-volant small mammals in the two predominant vegetation types: Ombrophilous Forest and Canga, and to examine how mining impacts these communities. Sampling was conducted from January 2010 to August 2011 in 11 sampling sites divided by the total area of Canga …

Benchmark Levels For The Consumptive Water Footprint Of Crop Production For Different Environmental Conditions: A Case Study For Winter Wheat In China, La Zhuo, Mesfin Mekonnen, Arjen Y. Hoekstra

Daugherty Water for Food Global Institute: Faculty Publications

Meeting growing food demands while simultaneously shrinking the water footprint (WF) of agricultural production is one of the greatest societal challenges. Benchmarks for the WF of crop production can serve as a reference and be helpful in setting WF reduction targets. The consumptive WF of crops, the consumption of rainwater stored in the soil (green WF), and the consumption of irrigation water (blue WF) over the crop growing period varies spatially and temporally depending on environmental factors like climate and soil. The study explores which environmental factors should be distinguished when determining benchmark levels for the consumptive WF of crops. …

Optimal Demand Response Models With Energy Storage Systems In Smart Grids, Mohemmed Masooud Alhaider

USF Tampa Graduate Theses and Dissertations

This research aims to develop solutions to relieve system stress conditions in electric grids. The approach adopted in this research is based on a new concept in the Smart Grid, namely, demand response optimization. A number of demand response programs with energy storage systems are designed to enable a community to achieve optimal demand side energy management.

The proposed models aim to improve the utilization of the demand side energy through load management programs including peak shaving, load shifting, and valley lling. First, a model is proposed to nd the optimal capacity of the battery energy storage system (BESS) to …