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Linking Plume Spreading To Hierarchical Stratal Architecture, Ramya Ramanathan

Browse all Theses and Dissertations

A new form of the Lagrangian-based model for macrodispersion of inert (non-reactive) solutes is presented. The model is based on a hierarchical expression of the spatial covariance of log-permeability representing a hierarchy of stratal unit types with a corresponding hierarchy of permeability subpopulations. The covariance expression representing the hierarchy of unit types is a linear sum of terms corresponding to the probability of transitioning across stratal unit types of different scales, and these terms are directly related to quantifiable geometric attributes of the hierarchical stratal architecture. The new macrodispersion model is also a linear sum of terms, with different integral …

Using Morphometrics, Phylogenetic Systematics And Parsimony Analysis To Gain Insight Into The Evolutionary Affinities Of The Calymenidae Trilobita, Alex J. Chestnut

Browse all Theses and Dissertations

The most common trilobite in the Silurian carbonates of Ohio - especially the Springfield Dolomite - is a species that has been assigned to at least five genera over the past 100 years. This trilobite has been variously referred to as Calymene celebra, Apocalymene celebra, Flexicalymene celebra, Gravicalymene celebra, and Sthenarocalymene celebra. Reexamination of the species "Calymene" celebra through parsimony and morphometric analysis was conducted to properly place this calymenid species within the correct genus. What compounds the confusion is that the characters used to seperate the genera within the family Calymenidae, and therefore create the basis for the argument …

Moderating Effects Of Knowledge, Gender, And Education On The Relationship Between Environmental Value Orientation And Support For Louisiana Coastal Restoration, Meya Voorhies Holloway

LSU Master's Theses

Coastal Louisiana marshes are eroding at a rate equivalent to one football field every thirty minutes. It is vital to understand the perceptions of the American public regarding this issue. I conducted a self-administered mail survey during the spring of 2006. The survey was sent to 4,500 residents living in the Mississippi River Valley. The survey was used to identify respondents environmental value orientations, assess respondents attitudes with regards to support for restoration funding for Louisiana’s coastal wetlands, and to determine if outside moderating effects occurred to make respondents with specific value orientations (Anthropocentric or Biocentric) more likely to support …

Historic Sediment Accretion Rates In A Louisiana Coastal Marsh And Implications For Sustainability, Rebekah Perkins Smith

LSU Master's Theses

Deltaic marshes of the Mississippi River in Louisiana disappeared at a rate of 88 km2 annually from 1956 to 2000 (Barras et al. 2003) as marshes become inundated by sea water. Marsh surface elevation varies spatially and temporally due to fluvial sediment deposition, resuspension, erosion, compaction, sea level rise, and organic matter accumulation and decomposition. If net accretion from sediment deposition and/or peat production is insufficient, marshes respond to sea level rise by migrating landward. Since human development prevents landward migration of marsh in Breton Sound Basin, Louisiana, marsh sustainability can only be achieved if vertical accretion keeps pace with …

M. Effects Of Land Use And Habitat On Stream Fish Assemblages In Tributaries Of The Lower Bogue Chitto Watershed, Washington Parish, Louisiana, Brian Michael Ward

LSU Master's Theses

My research focused on how fish communities are responding to watershed land use and instream habitat in tributaries of the Lower Bogue Chitto River. To address this question I electrofished and seined 10 sites in four tributaries of the Bogue Chitto River a total of 4 times each over the course of 15 months in 2007 and 2008. I characterized habitat by measuring water flow, water depth, substrate size, woody debris, temperature, and dissolved oxygen, and quantified heterotrophic plate counts, nutrients, and chlorophyll a concentrations at the end of the sampling period each year. Watershed land cover was measured with …

Efforts Of Coating And Testing High Aspect Ratio Microfabricated Nickel Gas Chromatography Columns, Arun Kumar K Paga

LSU Master's Theses

Gas chromatography (GC) is a widely used analytical technique, with applications in the chemical process industry, oil exploration, environmental monitoring, purification of substances, and general organic compound analysis. Although traditional GC’s are widely used they have their own disadvantages like high power consumption and long times for analysis. Several laboratories are working on the miniaturization of GC’s for rapid and onsite chemical analysis. Many researchers are currently working on the development of microfabricated columns for realizing a hand held GC sensor. Microfabricated nickel columns have been manufactured by Center for Advanced Microstructures & devices (CAMD), Baton Rouge. The columns are …

Using Demographic Models To Manage Chinese Privet (Ligustrum Sinense Lour.), Metha Martine Klock

LSU Master's Theses

Colonization of natural areas by Chinese privet (Ligustrum sinense Lour.) threatens biodiversity and preservation of native habitat in the southeastern United States. High rates of seed production and dispersal, coupled with clonal growth, result in a competitive advantage when introduced to novel areas. Land managers have attempted to control L. sinense through prolonged flooding, prescribed fire, and herbicide application with little success. I determined presence of L. sinense invasion in four sites in Louisiana and assessed key reproductive, growth, and survivorship characteristics defining its life course. I used vegetation surveys, germination trials, dendrochronology, and demographic models to elucidate stages in …

The Effects Of Bait Type, Trap-Soak Duration, And Trap Modification On Harvest Of Red Swamp Crawfish, David C. Hardee

LSU Master's Theses

The effects of bait type, trap-soak duration, and a trap entrance modification were evaluated from February through May 2008 in a 1.29 ha crawfish (red swamp crawfish, Procambarus clarkii) pond in southwest Louisiana. Commercial pyramid traps with three entrance funnels, 1.9-cm square-mesh vinyl-coated welded metal wire, were used. In trial 1, crawfish catch was evaluated in traps baited with Atlantic menhaden (Brevoortia tyrannus), a formulated dry bait, or a menhaden+formulated bait mixture, each at 24-h and 48-h soak durations. In trial 2, the escape of marked crawfish was evaluated in the presence or absence of bait at 24-h and 48-h …

Toxicological Monitoring And Protocol Development For Abandoned Pipeline Removal In Louisiana, Forest Christopher Wootten

LSU Master's Theses

Oil/Gas extraction have left Louisiana with a legacy of abandoned infrastructure across the State. Presently, the State has developed guidelines for the removal of abandoned vessels and abandoned on shore facilities. No such guidelines exist, however, for the network of abandoned pipelines present throughout the coastal zone of Louisiana. A pipeline removal was simulated in Lake Calcasieu, LA. The site was chosen because of the presence of many abandoned pipelines and previous work done on sight to remove the on shore infrastructure. In addition, the Calcasieu is an industrial water body, with potentially hazardous pollutants sequestered in the sediments of …

Distribution And Habitat Associations Of Breeding Secretive Marsh Birds In The Mississippi Alluvial Valley Of Northeast Louisiana, Jonathon Joseph Valente

LSU Master's Theses

Populations of many North American secretive marsh birds (SMBs) have declined over the past 30 years, primarily as a function of wetland loss. Ranges for many of these species encompass Louisiana and researchers have investigated various characteristics associated with breeding populations in coastal wetlands, yet similar knowledge is lacking for other parts of the state. I investigated distributions and habitat characteristics associated with breeding SMBs in wetlands and rice fields of the lower Mississippi Alluvial Valley (MAV) of northeast Louisiana. In the 2007 and 2008 breeding seasons we conducted repeated bird surveys in 118 wetlands and 76 rice fields. Common …

Creating An Empirically Derived Community Resilience Index Of The Gulf Of Mexico Region, Ariele Nicole Baker

LSU Master's Theses

As coastal areas increase in populations there is an increasing need to determine what community characteristics are most resilient to coastal disasters. This research proposes two methods to quantify community resilience. The factor analysis method results in a weighted additive index model of six variables to derive community resilience. The index places every community in the Gulf of Mexico on a scale from 0-1. The most resilient counties in the Gulf of Mexico region were found to be Hillsborough, FL, Pinellas, FL, Sarasota, FL, Hernando, FL, Okaloosa, FL, Kenedy, TX, and Jefferson, LA with a resilience score of 1. The …

Spatial-Temporal Responses Of Louisiana Forests To Climate Change And Hurricane Disturbance, Fugui Wang

LSU Doctoral Dissertations

This dissertation research focused on three questions: (1) what is the current carbon stock in Louisiana’s forest ecosystems? (2) how will the biomass carbon stock respond to future climate change? and (3) how vulnerable are the coastal forest resources to natural disturbances, such as hurricanes? The research utilized a geographic information system, remote sensing techniques, ecosystem modeling, and statistical approaches with existing data and in-situ measurements. Future climate changes were adapted from predictions by the Community Climate System Model on the basis of low (B1), moderate (A1B), and high (A2) greenhouse gas emission scenarios. The study on forest carbon assessment …

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 …

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 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, …

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 …

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 …

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 …

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 …

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 …

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 …

Creep Behavior Of Natural Fiber Reinforced Polymer Composites, Yanjun Xu

LSU Doctoral Dissertations

Creep behavior of natural fiber/polymer composites (NFPCs) was studied in response to the increasing application of this material as structural building products. Factors that influence creep behavior of the composites were investigated by analyzing creep curves of several different NFPC systems, which were designed for overall performance of the composites. Among different models, the 4-element Burgers type was mostly used for quantitative characterization of the creep curves to compare the properties of different composites. The parameters from the 4-element Burgers model were easily interpretable due to their physical meanings. Generalized Burgers models provided better fit by introducing extra Kelvin units, …

A Comparison Of Benthic Macroinvertebrate Assemblages Among Kryal And Rhithral Lake Outlets In The North Cascade Mountains, Kelley L. Turner

WWU Graduate School Collection

This study compares the physico-chemical conditions and composition of benthic macroinvertebrates from five rhithral (snowmelt-fed) and five kryal (glacially-fed) lake outlet streams in the North Cascade Mountains, WA. Non-metric, non-parametric cluster and association analysis (NMCAA) clearly separated outlet streams of kryal and rhithral origin based on physico-chemical and taxon variables. Kryal lake outlets were characterized by lower water temperatures, unstable in-stream channels and higher turbidity, discharge and fine substrates than rhithral sites. A total of 24,985 specimens representing 93 macroinvertebrate taxa were collected. Rhithral lake outlets had significantly higher densities and supported more taxa than kryal sites (9,049 ind./m2 and …

Illuminating Whole Effluent Toxicity Testing: Ultraviolet Radiation, Phototoxicity, And Pah-Contaminated Groundwater, Jason C. Fortner

WWU Graduate School Collection

In this study, the acute toxicity of polycyclic aromatic hydrocarbon (PAH) - contaminated groundwater to Daphnia magna and Pimephales promelas were characterized under both ambient laboratory lighting and ambient laboratory lighting supplemented with ultraviolet radiation (UVR) using USEPA Whole Effluent Toxicity (WET) test methods. Research has shown the toxicity of some PAHs to aquatic organisms increases significantly in the presence of sunlight or artificial UVR, a phenomenon known as photoactivated toxicity or phototoxicity. Based on these findings, the discharge of PAH-contaminated groundwater to surface waters may be a phototoxic hazard to aquatic organisms. Since WET tests are frequently employed to …