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Full-Text Articles in Physical Sciences and Mathematics

Evaluating The Feasibility Of Using Strain Measured During Sinusoidal Rate Pumping Tests To Characterize An Aquifer, Riley Blais Aug 2023

Evaluating The Feasibility Of Using Strain Measured During Sinusoidal Rate Pumping Tests To Characterize An Aquifer, Riley Blais

All Theses

Pumping tests with sinusoidal variation in pumping rate have been proposed as a method for improving aquifer characterization. These tests can interrogate a larger aquifer volume than slug tests and they can be more sensitive to small variations in drawdown. Current methods of using sinusoidal variations of rate are based on measuring pressure signals from the reservoir or aquifer, which requires access to monitoring wells. An alternative approach has been developed that measures the strain in the vadose zone instead of pressure in the reservoir. An instrument has been developed at Clemson University that can measure small strains using optical …


Assessing Key Factors Influencing Fire-Induced Spalling Of Concrete Using Explainable Artificial Intelligence (Xai), Mohammad Khaled Gazi Albashiti May 2023

Assessing Key Factors Influencing Fire-Induced Spalling Of Concrete Using Explainable Artificial Intelligence (Xai), Mohammad Khaled Gazi Albashiti

All Theses

This thesis adopts eXplainable Artificial Intelligence (XAI) to identify the key factors influencing the fire-induced spalling of concrete and to extract new insights into the fire-induced spalling phenomenon. In this pursuit, an XAI model was developed, validated, and then augmented with two explainability measures, namely, Shapley Additive exPlanations (SHAP) and Local Interpretable Model-Agnostic Explanations (LIME). The proposed XAI model not only can predict the fire-induced spalling with high accuracy (i.e., >92 %) but can also articulate the reasoning behind its predictions (as in, the proposed model can specify the rationale for each prediction instance); thus, providing us with valuable insights …


Impacts Of Preferential Flow On Tc-99and Np-237 Vadose Transport In Soils At The Savannah River Site, Josh Parris May 2023

Impacts Of Preferential Flow On Tc-99and Np-237 Vadose Transport In Soils At The Savannah River Site, Josh Parris

All Theses

Since the 1950s, the United States has produced approximately 90,000 metric tons of spent nuclear fuel (SNF) (Office of Nuclear Energy, 2022); however, no long-term storage solutions are available. Technecium-99 and neptunium-237, two fission products found in SNF, readily form highly mobile species in oxidizing conditions (Hu, 2008; Bondietti, 1979) and have respective half-lives of 2.13 x 105 and 2.14 x106 years (Hu, 2010). Considering these characteristics, 99Tc and 237Np are two risk-driving isotopes found in SNF storage. The process of macropore-facilitated preferential flow, transport through cracks within a soil matrix, has been recognized to increase …


Mysteerio: Multi-Regional Environmentally Extended Input-Output Model For United States, Yash Srivastava Dec 2022

Mysteerio: Multi-Regional Environmentally Extended Input-Output Model For United States, Yash Srivastava

All Theses

This research work titled My State Environmentally Extended Regional Input-Output (MYSTEERIO) is based on the concept of multi-regional environmentally extended input-output (MREEIO), which is a combination of lifecycle thinking and economics principles. Numerous studies have highlighted the advantages of using this methodology to determine the environmental impacts associated with economic activities for a region. However, no prior attempt has been made to conduct a state-level analysis for the US. This research work thus tries to estimate the impacts embodied due to the consumption of goods and services at the state level by using the MREEIO principles. Extensive coverage of the …


Application Of A 14c-Assay To Assess Methanotrophic Biodegradation Of Tce In Low Ph Groundwater, Evan Groome Aug 2022

Application Of A 14c-Assay To Assess Methanotrophic Biodegradation Of Tce In Low Ph Groundwater, Evan Groome

All Theses

Current biological strategies for remediating trichloroethylene (TCE) in low pH aquifers (i.e., pH14C-TCE assay was developed to determine pseudo first-order rate constants for the degradation of TCE in microcosms containing soil and groundwater from the Boeing Michigan Aeronautical Research Center (BOMARC) superfund site, where the pH ranges from 4.1 to 4.9. The 14C-TCE assay was also adapted to calculate soil-normalized rate constants for data from this site, as well as data that Szwast21 collected from the Beltsville Agricultural Research Center (BARC). In addition to natural attenuation, biostimulation through amendments of methane and nutrients were also assessed. This treatment …


Floating Treatment Wetlands For Brackish Waters: Plant Selection And Nutrient Uptake Potential., Andrea Landaverde May 2022

Floating Treatment Wetlands For Brackish Waters: Plant Selection And Nutrient Uptake Potential., Andrea Landaverde

All Theses

Brackish water bodies in coastal regions provide critical ecosystem services that support human and environmental health. Anthropogenic activities such as agricultural and industrial activities, construction, urban settlements, and tourism contribute to increased inputs of nitrogen (N) and phosphorus (P) in brackish coastal ecosystems. Excess nutrients can lead to impaired water quality and affect marine organisms. Floating treatment wetlands (FTWs) are a vegetated-base technology used to remove contaminants from water column, that has been mainly studied and applied in freshwater systems. Application of FTWs in brackish systems requires further investigation, as high salinity in brackish waters could result in toxicity to …


Fate And Transport Of Toxoplasma Gondii Oocysts In Saturated Porous Media: Effects Of Electrolytes And Natural Organic Matter, Christian Pullano May 2022

Fate And Transport Of Toxoplasma Gondii Oocysts In Saturated Porous Media: Effects Of Electrolytes And Natural Organic Matter, Christian Pullano

All Theses

Toxoplasma gondii is a pathogenic microorganism that is currently a threat to public health. Understanding the fate and transport of T. gondii through the soil and groundwater is vital in determining the risk it poses to water resources and human health. The physico-chemical interactions between the groundwater and the bio colloid within an aquifer will dictate its mobility and its ability to infect humans. This research examines how various naturally occurring groundwater chemistries containing organic compounds and monovalent and divalent salt solutions will alter the fate and transport of T. gondii. Solutions containing various concentrations of humic acid, fulvic …


Bromide Removal From Surface Waters By Silver Impregnated Activated Carbon, Chen Chen Jan 2015

Bromide Removal From Surface Waters By Silver Impregnated Activated Carbon, Chen Chen

All Theses

Bromide is a precursor of disinfection by-products (DBPs) during potable water treatment, because it causes the formation of brominated DBPs that are more cyto- and geno-toxic than their chlorinated analogues. Due to the potential health risks of DBPs, the United States Environmental Protection Agency (USEPA) has been imposing increasingly stringent regulations for controlling the DBPs. Therefore, removal of bromide ions from source waters becomes critical for controlling the DBPs formation. In my study, it was hypothesized that silver impregnated activated carbon (SIAC) can be a promising adsorbent for bromide removal from water. The main research objectives of this study were …


Fast Fission Neutron Detection Using The Cherenkov Effect, Matthew Millard Dec 2014

Fast Fission Neutron Detection Using The Cherenkov Effect, Matthew Millard

All Theses

The Cherenkov effect in optically clear media of varying indices of refraction and composition was investigated for quantification of fast neutrons. The ultimate application of the proposed detection system is criticality monitoring. The optically clear medium, composed of select target nuclei, was coupled to a photomultiplier tube. Neutron reaction products of the target nuclei contained within the optical medium emit beta particles and gamma rays that produce Cherenkov photons within the medium which can be detected. Assessed media include quartz (SiO2), sapphire (Al2O3), spinel (MgAl2O4), and zinc sulfide (ZnS), which were irradiated with un-moderated 252Cf. Monte Carlo N-Particle (MCNP) code …


An Examination Of Radionuclide Transport In The Vadose Zone Using Field Lysimeters, Michael Witmer Aug 2014

An Examination Of Radionuclide Transport In The Vadose Zone Using Field Lysimeters, Michael Witmer

All Theses

Understanding how radionuclides interact in the subsurface is important for the remediation of contaminated sites, assessment of risk due to radioactive waste disposal, and designing new radioactive waste management strategies. The current understanding of the geochemical behavior of radionuclides in the subsurface and more specifically the vadose zone has been developed through reactive transport modeling supplemented by laboratory experiments. Interactions between radionuclides with the mineral particles and organic matter in the vadose zone can be very complex and while laboratory experiments produce valuable data, few controlled, intermediate scale transport studies have been performed. In order to accurately predict vadose zone …


Spatial And Temporal Analysis Of Land Cover Change, Sedimentation And Water Quality In The Lake Issaqueena Watershed, South Carolina, Cassie Pilgrim Aug 2014

Spatial And Temporal Analysis Of Land Cover Change, Sedimentation And Water Quality In The Lake Issaqueena Watershed, South Carolina, Cassie Pilgrim

All Theses

Soil erosion and increased sediment yields within a watershed lead to impaired water quality, decreased availability of wildlife habitat and reduced recreational opportunities. While some sedimentation occurs naturally within a water system, most erosion processes are the result of anthropogenic activities across a landscape, namely changes in land use and land cover (LULC). This study was conducted to determine temporal and spatial sedimentation trends in the Lake Issaquena watershed using sonar logging equipment, geographic information systems (GIS) and limited hydrologic data from the Soil Conservation Service (1941 and 1949). Sediment deposition was analyzed in relation to several key factors that …


Anaerobic And Aerobic Biodegradation Of The Oil Dispersant Components 1,2-Propanediol And 2-Butoxyethanol In Seawater, Benjamin Rhiner Aug 2014

Anaerobic And Aerobic Biodegradation Of The Oil Dispersant Components 1,2-Propanediol And 2-Butoxyethanol In Seawater, Benjamin Rhiner

All Theses

Oil spills are a recurring issue associated with fossil fuel consumption. The largest accidental oil spill in the history of the petroleum industry was the Deepwater Horizon explosion and seafloor well blowout, where the Deepwater Horizon oil rig exploded and sank, allowing the well to gush uncontrolled from April 20, 2010, until it was capped on July 15, 2010, releasing an estimated 210,000,000 gallons of oil. Oil dispersants were used in unprecedented quantities during the cleanup response to the spill with a total of 1,840,000 gallons of the dispersant COREXIT being applied. The goal of this research was to evaluate …


Adsorption Of Synthetic Organic Chemicals: A Comparison Of Superfine Powdered Activated Carbon With Powdered Activated Carbon, Semra Bakkaloglu May 2014

Adsorption Of Synthetic Organic Chemicals: A Comparison Of Superfine Powdered Activated Carbon With Powdered Activated Carbon, Semra Bakkaloglu

All Theses

In literature, manufacturer-supplied powdered activated carbon has been ground to produce submicron particles with mean diameter lower than 1µm for use as an adsorbent during water treatment. Superfine powdered activated carbon (SPAC) can be used for removal of natural organic matter as well as synthetic organic chemicals (SOCs) from water. It has been suggested that SPAC has higher adsorption capacity than powdered activated carbon (PAC) due to larger external surface area and mesopore volume. Another advantage of SPAC over PAC is the faster uptake rate for both NOM and SOC during adsorption owing to small particle size. Therefore, understanding SPAC …