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Full-Text Articles in Physical Sciences and Mathematics

Structural, Charge Transport, Gas Sensing, Magnetic, Pseudocapacitive, And Electrocatalytic Properties Of Perovskite Oxides., Surendra Bahadur Karki May 2022

Structural, Charge Transport, Gas Sensing, Magnetic, Pseudocapacitive, And Electrocatalytic Properties Of Perovskite Oxides., Surendra Bahadur Karki

Electronic Theses and Dissertations

Perovskites are functional materials with the general formula ABO3 (A = alkali, alkaline earth or lanthanoid cations and B = transition metal or main group cations). These materials are marked by a variety of crystal structures and interesting properties such as colossal magnetoresistance, ferroelectricity, multiferroicity, superconductivity, pseudocapacitance, gas sensing, charge transport, and electrocatalytic properties. The formula of perovskite can be written as AA’BB’O6, when there is ordering between two cations over A and B-sites. Such compounds are called double perovskite oxides. Some amount of oxygen could be lost from crystal structure without decomposition of the phase. Such …


The Impact Of Sea-Level Rise In Numerically Modeled Landfalling Hurricanes: Katrina And The Gulf Coast., Serenity Nadirah Mercuri May 2022

The Impact Of Sea-Level Rise In Numerically Modeled Landfalling Hurricanes: Katrina And The Gulf Coast., Serenity Nadirah Mercuri

Electronic Theses and Dissertations

With climate change, landfalling hurricanes become an increasing threat to coastal regions. However, the interactions between the coastal landscape and landfalling hurricanes are often overlooked when addressing sea-level rise outside of inundation and independent of sea surface temperature. This study analyzed the potential impacts regarding structure and intensity as a result of sea-level rise in the Gulf of Mexico using the WRF-ARW numerical model coupled with a 1D ocean model. Analysis showed that 10 m windspeed from landfall forward was higher in modified coastlines, and minimum sea-level pressure post-landfall was consistently lower for modified runs where storms maintain a higher …


A Remote Sensing Perspective: Mapping The Human Footprint In The Zambezi Region Of Namibia., Ariel E Weaver Dec 2021

A Remote Sensing Perspective: Mapping The Human Footprint In The Zambezi Region Of Namibia., Ariel E Weaver

Electronic Theses and Dissertations

The “human footprint” can be used as a general proxy to estimate human activities across the landscape. The human footprint in the Zambezi Region of Namibia is critically important for regional management of conservation efforts and land use planning. The land covers in the Zambezi Region are characteristically difficult to separate spectrally, due to a highly heterogeneous savanna landscape. Object Based Image Analysis (OBIA) and Random Forest (RF) methods are notable for their ability to improve classification accuracies of remotely sensed imagery. In this study, I investigate the extent of the human footprint in the Zambezi Region of Namibia, using …


Presence Of Severe Acute Respiratory Syndrome Coronavirus 2 In Urban Streams Receiving Sewer Overflow, Louisville, Kentucky, Usa., Cullen Hunter May 2021

Presence Of Severe Acute Respiratory Syndrome Coronavirus 2 In Urban Streams Receiving Sewer Overflow, Louisville, Kentucky, Usa., Cullen Hunter

Electronic Theses and Dissertations

Pathogens may enter surface waters as they are shed in human feces and potentially delivered to surface waters via sewer overflows, particularly in the eastern United States. This study examined of the presence of fecal indicators in two forks of Beargrass Creek in Louisville, Kentucky. Surface water grab samples (N=30), sediment samples, water quality, and a paired wastewater surveillance study were analyzed. SARS-CoV-2 was detected in a single stream sample despite ubiquitous presence of the virus within the area in wastewater and consistent evidence of a human fecal indicator. These findings demonstrate the need for more green and gray infrastructure …


Analyzing The Effects Of Of Seasonal Land Cover And Precipitation On The Sediment Delivery Ratio Of An Agriculture Dominated Watershed., Jonah Liebman May 2020

Analyzing The Effects Of Of Seasonal Land Cover And Precipitation On The Sediment Delivery Ratio Of An Agriculture Dominated Watershed., Jonah Liebman

Electronic Theses and Dissertations

Soil erosion is of escalating importance as increasing population and climate change have put increasing pressures on agricultural food production. Vegetation and precipitation are two factors that control the amount of soil erosion extant within a region. Sediment delivery ratios (SDRs) assess the ratio of soil eroded from a watershed system that is permanently removed from the system through stream sediment discharge. Using 1) river discharge and sediment concentration data and 2) the Revised Universal Soil Loss Equation (RUSLE), this thesis analyzes fluctuations in monthly SDRs for an average hydroclimatological crop-harvest season for the Senachwine Creek watershed, IL. Through calculating …


A Multi-Plot Assessment Of Vegetation Structure Using A Micro-Unmanned Aerial System (Uas) In A Semi-Arid Savanna Environment., Nicholas E Kolarik May 2019

A Multi-Plot Assessment Of Vegetation Structure Using A Micro-Unmanned Aerial System (Uas) In A Semi-Arid Savanna Environment., Nicholas E Kolarik

Electronic Theses and Dissertations

Unmanned Aerial Systems (UAS) have emerged as a capable platform for measuring vegetation health, structure and productivity. Products derived from UAS imagery typically have much finer spatial resolutions than traditional satellite or aircraft imagery, allowing the spectral and structural heterogeneity of vegetation to be mapped and monitored with more detail. This study uses UAS-captured imagery from the Chobe Enclave of northern Botswana. Flights were conducted across a gradient of savanna sites classified as grass-, shrub-, or tree-dominated. We compare multiple approaches for extracting woody vegetation structure from UAS imagery and assess correlations between in situ field measurements and UAS estimates. …


Potential For Developing Run-Of-River Systems In Eastern Kentucky : A Gis Approach To Site Suitability., Thomas Jeffords May 2018

Potential For Developing Run-Of-River Systems In Eastern Kentucky : A Gis Approach To Site Suitability., Thomas Jeffords

Electronic Theses and Dissertations

Coal has a questionable future with the potential exhaustion of available coal. Alternate sources of energy production should be considered, such as hydropower dams, or the more environmentally friendly, Run of River (RoR) hydropower system. This study seeks to answer the question: What is the potential for RoR hydroelectric systems in Eastern Kentucky counties with significant decreases in coal production and employment? I hypothesize that GIS will identify suitable sites within Pike County for RoR systems. Site suitability for Eastern Kentucky was assessed and determined that Pike County did not have a suitable physical environment for RoR systems. The power …


Greater London In The 21st Century : Assessing Coastal Flooding Mitigation Preparedness And Regional Population Risk In The Face Of Projected Sea-Level Rise., Nathan K Wright Dec 2017

Greater London In The 21st Century : Assessing Coastal Flooding Mitigation Preparedness And Regional Population Risk In The Face Of Projected Sea-Level Rise., Nathan K Wright

Electronic Theses and Dissertations

Recent projections of +6-9m sea-level rise (SLR) over the next several decades present many social challenges for coastal regions during the 21st century. These projections were applied to Greater London, UK as areal interpolated historical census data was overlaid on a 50m DEM alongside a polyline projection of the Thames Barrier. Population was projected to milestones of 2041, 2071, and 2101 using a capped, aggregated growth rate for each polygon while SLR was simulated for 1m, 5m, and 9m scenarios. The Thames Barrier maintained integrity for 1m and 5m scenarios but was breached at 9m. Population continued to increase …


Remotely Sensed Heat : Variation And Change In Surface Urban Heat Islands In A Temperate Eco-Region Of The United States., Jeremy Sandifer May 2017

Remotely Sensed Heat : Variation And Change In Surface Urban Heat Islands In A Temperate Eco-Region Of The United States., Jeremy Sandifer

Electronic Theses and Dissertations

Urban heat island (UHI) is a term used to describe increased surface and atmospheric temperatures in an urban core relative to surrounding non-urbanized areas. To examine the variability introduced into derived estimates of the surface UHI, this study constructs and compares multiple remotely sensed indicators of the surface UHI for major metropolitan cities of a temperate eco-region of the United States. The Moderate Resolution Imaging Spectroradiometer (MODIS) 8-day, 500-meter product (MOD11A2) is the source data used to calculate six different RS-derived UHI indicators for the year 2002 to 2012. The different SUHI indicators are evaluated using the Spearmans Rho rank-order …


An Analysis Of The Relationship Between Snowpack And Groundwater Across Utah Watersheds., Samuel Wright May 2017

An Analysis Of The Relationship Between Snowpack And Groundwater Across Utah Watersheds., Samuel Wright

Electronic Theses and Dissertations

This thesis examined what type of relationship existed between snow water equivalence (SWE) volume and groundwater elevation within six sub-watersheds in Utah. Data was gathered on SWE from seventeen SNOTEL sites and groundwater elevation data was gathered from six continuously monitored groundwater wells. This data was gathered for January through May for 2011, 2013, and 2014 in order to represent the water conditions that were above average, below average, and average respectively. Using MLR formulas the total SWE for each sub-watershed was determined for each year/month. Afterwards a correlation analysis was performed to determine if any association existed between SWE …


Analyzing The Phenologic Dynamics Of Kudzu (Pueraria Montana) Infestations Using Remote Sensing And The Normalized Difference Vegetation Index., Faye Peters May 2016

Analyzing The Phenologic Dynamics Of Kudzu (Pueraria Montana) Infestations Using Remote Sensing And The Normalized Difference Vegetation Index., Faye Peters

Electronic Theses and Dissertations

Non-native invasive species are one of the major threats to worldwide ecosystems. Kudzu (Pueraria montana) is a fast-growing vine native to Asia that has invaded regions in the United States making management of this species an important issue. Estimated normalized difference vegetation index (NDVI) values for the years 2000 to 2015 were calculated using data collected by Landsat and MODIS platforms for three infestation sites in Kentucky. The STARFM image-fusing algorithm was used to combine Landsat- and MODIS-derived NDVI into time series with a 30 m spatial resolution and 16 day temporal resolution. The fused time series was …


Urban Flooding And Sewer Inundation On The University Of Louisville Belknap Campus., Justin T. Hall May 2016

Urban Flooding And Sewer Inundation On The University Of Louisville Belknap Campus., Justin T. Hall

Electronic Theses and Dissertations

Over the past few decades on the University of Louisville Belknap campus urban flooding has become more frequent as a result of surface water runoff and sewer inundation. This urban flooding is a result of ongoing watershed urbanization and rapid expansion of the local sewer system to accommodate the expanding city of Louisville. However little research has been conducted on this issue, despite continued flooding on and adjacent to campus. Using the EPA Storm Water Management Model (SWMM) we applied a dual drainage modeling approach that combines both surface and subsurface drainage data to produce a flood hydrograph at the …