Engineering Commons^™

Interfacing Of Neuromorphic Vision, Auditory And Olfactory Sensors With Digital Neuromorphic Circuits, Anup Vanarse

Theses: Doctorates and Masters

The conventional Von Neumann architecture imposes strict constraints on the development of intelligent adaptive systems. The requirements of substantial computing power to process and analyse complex data make such an approach impractical to be used in implementing smart systems.

Neuromorphic engineering has produced promising results in applications such as electronic sensing, networking architectures and complex data processing. This interdisciplinary field takes inspiration from neurobiological architecture and emulates these characteristics using analogue Very Large Scale Integration (VLSI). The unconventional approach of exploiting the non-linear current characteristics of transistors has aided in the development of low-power adaptive systems that can be implemented …

Field Scale Application Of Nanoscale Zero Valent Iron: Mobility, Contaminant Degradation, And Impact On Microbial Communities, Chris M.D. Kocur

Electronic Thesis and Dissertation Repository

This thesis began by verifying that nanoscale zero valent iron (nZVI) synthesis methods could be scaled up and implemented at the field scale in a safe manner. This led to successful demonstration of nZVI injection and mobility under constant head gravity injection into a contaminated utility corridor in Sarnia, Ontario. Where field studies have fallen short in the past was linking the somewhat qualitative field geochemical parameters to other evidence of nZVI transport. Definitive nZVI detection was elusive in previous field studies due to the highly reactive nature of the particles caused by their high surface area. nZVI was detected …

Estimating Streambank Erosion Using Gps-Based Watershed-Scale Video Mapping And Usepa Bancs For The Development Of Sediment Tmdls, Kelsey Jo Hensley

Masters Theses

According to the United States Environmental Protection Agency (USEPA), sediment is one of the most common water pollutants in the nation’s rivers. Consequently, the identification of streambank locations with high erosion potential is important in reducing sediment input via management and monitoring practices. Furthermore, the estimation of erosion rates and sediment loads can assist in the development of Total Maximum Daily Loads (TMDLs). The objective of this study was to integrate two USEPA-recommended approaches with the Streambank Video Mapping System (SVMS) in order to predict site-specific Total Daily Sediment Loads (TDSLs) and calculate sediment TMDLs for streambank erosion over several …

Methane Production By A Packed-Bed Anaerobic Digester Fed Dairy Barn Flush Water, Sean Richard Thomson

Master's Theses

Packed-bed digesters are an alternative to covered lagoon digesters for methane production and anaerobic treatment of dilute wastewaters such as dairy barn flush water. The physical media of packed-beds retain biofilms, often allowing increased treatment rates. Previous studies have evaluated several types of media for digestion of dilute wastewaters, but cost and media fouling have setback commercial development. A major operational cost has been effluent recirculation pumping.

In the present effort, a novel approach to anaerobic digestion of flush dairy water was developed at pilot-scale: broken walnut shells were used as a low-cost packed-bed medium and effluent recirculation was replaced …

Using Gis To Delineate Headwater Stream Origins In The Appalachian Coal-Belt Region Of Kentucky, Jonathan A. Villines

Theses and Dissertations--Biosystems and Agricultural Engineering

Human activity such as surface mining can have substantial impacts on the natural environment. Performing a Cumulative Hydrologic Impact Assessment (CHIA) of such impacts on surface water systems requires knowing the location and extent of these impacted streams. The Jurisdictional Determination (JD) of a stream’s protected status under the Clean Water Act (CWA) involves locating and classifying streams according to their flow regime: ephemeral, intermittent, or perennial. Due to their often remote locations and small size, taking a field inventory of headwater streams for surface mining permit applications or permit reviews is challenging. A means of estimating headwater stream location …

Experiments To Measure The Effects Of Timber Harvesting Equipment On Surface Lithic Scatters, Douglas J. Baughman

All Master's Theses

The importance of cultural resource preservation cannot be overstated; however local economies are at least as important. Due to conservative archaeological site protection practices in Region 5 of the United States Forest Service, the economy of Northeastern California is being adversely affected. In an attempt to help the Forest Service make more informed management decisions and improve the Northeastern California economy, I undertook experiments on the effects of timber harvesting on lithic scatters on Modoc National Forest. The experiments involved placement of 225 glass tiles (proxy lithics) in each of three plots subject to vehicle traffic and log dragging by …

Topographic Influences On Trends And Cycles In Nutrient Export From Forested Catchments On The Precambrian Shield, Samson G. Mengistu

Electronic Thesis and Dissertation Repository

This dissertation explored topographic controls on spatial and temporal patterns in water yield and nutrient (carbon, nitrogen and phosphorus) export from forested headwater catchments in the Turkey Lakes Watershed in central Ontario, where other factors contributing to differences in water yield and nutrient export, including climate, geology, forest, and soils, are relatively constant. Topographic characteristics, including (a) hydrological flushing potential (expansion of water table into nitrate-N producing areas); (b) hydrological storage potential (area of wetlands, which can alternatively allow water and nutrients to bypass wetlands when storage capacity is filled with water or to trap them when not filled); and …

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 …

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 …

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 …

Effect Of Spatial And Temporal Variability Of Antecedent Moisture Content On Model-Generated Runoff From An Arid Watershed, William J. Meyer

UNLV Theses, Dissertations, Professional Papers, and Capstones

Streams in the arid southwest are typically ephemeral, and stream gages are not commonly available. Consequently, runoff data from storm events is not available, and flood control facility design or other water resource related decisions are based on synthetic hydrographs. In the Mojave Desert region of Southern Nevada, the duration of storm used to develop these synthetic hydrographs is the 6 hour storm. The 6 hour storm is used to simulate high intensity summer storms. Additionally, soils information used in the calculations for these synthetic hydrographs is taken from maps that are generally developed for a broad range of issues …

Improving Ensemble Streamflow Prediction Using Interdecadal/Interannual Climate Variability, Kenneth W. Lamb

UNLV Theses, Dissertations, Professional Papers, and Capstones

The National Weather Service’s (NWS) river forecast centers provide long-term water resource forecasts for the main river basins in the U.S. The NWS creates seasonal streamflow forecasts using an ensemble prediction model called the Extended Streamflow Prediction (ESP) software. ESP creates runoff volume forecasts by taking the current observed soil moisture and snowpack conditions in the basin and applying them to historical temperature and precipitation scenarios. The ESP treats every historic input year as a likely scenario of future basin conditions. Therefore improving the knowledge about how long-term climate cycles impact streamflow can extend the forecast lead time and improve …

Effects Of 2000-2050 Global Climate Change On Ozone And Particulate Matter Air Quality In The United States Using Models-3/Cmaq System, Yun-Fat Lam

Doctoral Dissertations

The Models-3/Community Multi-scale Air Quality modeling system (CMAQ), coupled with Goddard Institute for Space Studies (GISS) atmospheric General Circulation Model (GCM), fifth Generation Mesoscale Model system (MM5), and Goddard Earth Observing System-CHEMistry (GEOS-Chem), was used to simulate atmospheric concentration of ozone and particulate matter over the continental United States 12-km and 36-km (CONUS) domains at year 2000 and year 2050. In the study, GISS GCM model outputs interfaced with MM5 were utilized to supply the current and future meteorological conditions for CMAQ. The conventional CMAQ profile initial and boundary conditions were replaced by time-varied and layer-varied GEOS-Chem outputs. The future …

Assessment Of Impacts To Hydroclimatology And River Operations Due To Climate Change Over The Colorado River Basin, William Paul Miller

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation investigated the impacts of climate change to the hydroclimatology and river and reservoir management operations within the Colorado River Basin. Preliminary research indicated observed warming trends throughout the Colorado River Basin and corresponding seasonal trends to the magnitude and timing of runoff in the Colorado River Basin. Subsequent research investigated the changing character of precipitation and corresponding impacts to streamflow over the Colorado River Basin. Analysis of snowpack telemetry (SNOTEL) stations over the American West and Colorado River Basin indicated decreasing trends in annual snowpack, often at least at the 95% confidence interval. A shorter snowpack season was …

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 …

The Potential For Ch4-Enriched Biogas As A Transport Fuel In Ireland, Niamh Power

Theses

Ireland needs a biofuel industry- to aid compliance with the Kyoto Protocol, the Biofuels Directive and to secure its energ>' supply. The overall aim of this work is to assess the potential of CH4-enriched biogas as a transport fuel in Ireland. Biogas is produced during the anaerobic digestion of biomass. This work investigates biogas production from two different feedstocks; biodegradable municipal waste and agricultural crops. To assess the potential for biogas as a transport fuel the alternatives to biogas are investigated and compared. Thus digestion and composting of biodegradable municipal waste, and biogas and ethanol production from agricultural crops …

Characterization Of Microbial Processes That Degrade Chlorinated Solvents In A Constructed Wetland Using Organic Acid And Inorganic Anion Concentration Profiles, Chad B. Bondurant

Theses and Dissertations

Chlorinated solvents have been used in industrial cleaning and degreasing processes in the United States since the early 1900s, and their induction into the environment increased significantly with the growth of industrial processes over the past century. PCE, TCE and their daughter products have been associated with a number of human health concerns and are currently the most common contaminants found in groundwater in the United States. Wetlands possess characteristics necessary for the complete degradation of chlorinated ethenes by microorganisms via anaerobic and aerobic regions that foster the necessary oxidation-reduction conditions. Organic acid and inorganic anion concentrations were evaluated in …

Environmental Management Of Waste Electrical & Electronic Equipment (Weee) In Ireland, Simon Wilkinson

Theses

This thesis follows two previous studies by the Author on the calculation of theoretical WEEE arisings, and an assessment of ecodesign practices in Ireland. It has established collection trials in five different locations throughout Ireland in order to characterise and quantify WEEE arisings, and to examine outlets for collected WEEE. Overall, during the twelve months of collection at the project locations, more than 450 tonnes of WEEE was collected from the public and recycled. Within the catchments of each facility, collection rates of between 2.1 and 3.5 kg/person/year were achieved during the twelve-month trial period. With further public awareness raising …

A System Dynamics Model Of The Bioavailability Of Metals In Constructed Wetland Sediment, Timothy S. Wood

Theses and Dissertations

Constructed wetlands used for storm water treatment accumulate metals primarily in their sediment. This sediment has the potential to produce toxic effects in benthic organisms at some period in time. Bioavailability of metals in sediment is directly linked to pore water metal activity. The mechanisms that influence pore water metal activity are included in physical, chemical, and biological processes. A system dynamics model was developed to represent these processes and the major influences affecting pore water metal activity in a treatment wetland receiving storm water influent. The model structure and behavior was tested and validated using several system dynamics validation …

Modeling Uptake And Translocation Of Lead (Pb) In Maize For The Purposes Of Phytoextraction, Mark A. Brennan

Theses and Dissertations

Phytoextraction is a remediation technology that uses plants to remove heavy metals from soil. This technology has the potential to decrease the costs of remediating contaminated sites by several orders of magnitude compared to traditional technologies. To effectively implement this technology requires an understanding of the plant processes that control uptake and translocation of metals from the soil. Currently these processes are poorly understood, and especially so for Pb. The purpose of this thesis was to gain insights concerning the plant mechanisms that control uptake and translocation of Pb and how these mechanisms interact to control levels of Pb accumulation …