Physical Sciences and Mathematics Commons^™

Soil Moduli Obtained From A Back Pressure Constant Rate Of Strain Bender Element Consolidation Apparatus, Yi Zhao

Graduate Theses and Dissertations

A back-pressure saturated, constant-rate-of-strain consolidation device was modified to incorporate bender elements (BP-CRS-BE) and thus allowed for shear wave measurements during consolidation tests. This newly fabricated system has many advantages over other previous or current devices: 1) it can be utilized not only for laboratory prepared soil samples but also for field sampled soils such as Shelby tube samples, and 2) continuous compression curves, and continuous values of vertical hydraulic conductivity and coefficient of consolidation can be acquired with a significant reduction in testing time. Soil modulus values such as shear modulus and constrained modulus are also able to be …

Stratigraphy And Depositional Environment Of The Middle Atoka Formation, Central Arkoma Basin, Western Arkansas, Yueyang Wang

Graduate Theses and Dissertations

Wire line logs are widely used in analysis of the subsurface stratigraphy of the middle Atoka Formation, Central Arkoma Basin, Western Arkansas. SP log, Gamma ray log, resistivity log and conductivity log provide valuable information to construct cross sections.

The middle Atoka formation is composed of a succession of shale and sandstone alternations with thickness reaching approximately 3000 feet in the study area. It contains several sandstone units which include Morris, Tackett, Areci, Bynum, Casey and Dunn”A” separated by shale intervals. The purpose of this study is to identify these units and predict sequence stratigraphy and depositional environment by constructing …

Soil And Plant Property Differences Among High-Yield Soybean Areas In Arkansas, Taylor Cass Adams

Graduate Theses and Dissertations

Continued achievement of soybean [Glycine max (L.) Merr.] yields greater than 6719 kg ha-1 (100 bu ac-1) will depend on decreasing the yield gap, which is contingent on gathering more information regarding the soil physical, chemical, and microbiological environment and the main plant factors contributing to high-yield soybean. Therefore, understanding the main factor differences between high- and average-yield areas may provide insight for making management decisions to increase yields. The objectives of this study were i) to evaluate the effects of region and soil depth on soil property differences between high- and average-soybean-yielding areas, ii) to determine which soil properties …

Sedimentary Petrology Of The Hartshorne Formation, Southeastern Arkoma Basin, Arkansas, Ruizhe Yin

Graduate Theses and Dissertations

The Pennsylvanian Hartshorne Sandstone crops out in an east trending belt across central Arkansas immediately north of the Ouachita orogenic belt and south of the Boston Mountains. The unit, composed of massive to cross bedded sandstone ranging to 150m in thickness, was deposited by a west-flowing river system that extended from central Arkansas to southeastern Oklahoma. The source of the sediment has been extensively discussed but not completely established. The object of this thesis is to constrain the source area and terrain based on thin section mineralogy and texture. Thin sections were prepared from outcrops in the Arkoma Basin and …

Cover Crop Establishment And Potential Benefits To Arkansas Farmers, Ashley Elizabeth Humphreys

Graduate Theses and Dissertations

Soybean farmers in Arkansas need best management practices (BMPs) that maximize the benefits of using cover crops including planting date and fertilization recommendations. An evaluation of cover crop species, planting dates, seeding rates, fertilizer rates, and N accumulation aids in providing these BMPs. The first objective of this research is to assess the effect of planting date on biomass production, as well as looking at the interaction of seeding rate or fertilizer rate for legumes or non-legumes, respectively, using Austrian winter pea (Pisum sativum), cereal rye (Secale cereale), black oats (Avena strigosa), wheat (Triticum aestivum), and tillage radish (Raphanus sativus). …

Temporal Co2 Variations And The Influence Of Bat Colonies In Speleogenesis: Continuous Co2 Monitoring In War Eagle Cavern, Arkansas, Ginny Sue Holcomb

Graduate Theses and Dissertations

Dissolved concentrations of CO2 in a karst aquifer are a major control on calcite dissolutional processes, as CO2 combines chemically with water to form carbonic acid. As increasing amounts of CO2 are added to the system, greater resultant water aggressivity generates greater rates of dissolution. Spatial and temporal variations in carbon flux through the system may occur over a range of time scales, and high-resolution data collection is needed to truly understand and characterize such variability. Continuous CO2 monitoring in War Eagle Cavern, Arkansas, will suggest a number of influential parameters with varying degrees of importance throughout an annual cycle. …

How Do Designers Of The Built Environment Attempt To Make Ecological Sustainability Sensory Legible?, Carly L. Bartow

Architecture Undergraduate Honors Theses

This paper attempts to provide a theoretical framework for making ecosystem function and ecologically sustainable design more perceptible or sensible to people through architecture and the built environment. Design features of the Bertschi School Science Wing and the Bullitt Center in Seattle, Washington are incorporated to illustrate the sensory legibility of ecological sustainability criteria.The criteria are available to designers to help educate a building's occupants on environmentally sustainable design and motivate more sustainable behavior.

A Gis Approach To Modeling Groundwater Levels In The Mississippi River Valley Alluvial Aquifer, Josef Orion Lilly

Graduate Theses and Dissertations

Groundwater depletion, a subject of growing concern for a significant portion of Arkansas, may lead to future economic challenges for the Arkansas Delta region. The Mississippi River Valley Alluvial Aquifer is the uppermost aquifer and features the largest groundwater capacity in the Mississippi Embayment Aquifer System. The Mississippi River Valley Alluvial Aquifer, commonly referred to as the “alluvial aquifer”, spans 53,000〖 km〗^2 underlying portions of Arkansas, Kentucky, Louisiana, Mississippi, Missouri, Illinois, and Tennessee. As the alluvial aquifer trends southward for approximately 250 miles alongside the Mississippi River, its geographical extent ranges from 50 to 125 miles wide. There is a …

Cryogenic Viscous Liquids On Icy Moons, Danielle Neighbour

Civil Engineering Undergraduate Honors Theses

The study of cryogenically viscous liquids such as methane and ethane offers critical insight into the behavior of fluids on icy moons such as Saturn’s moon Titan. Shrouded by a hazy hydrocarbon shield, Titan’s significant nitrogen atmosphere of 1.5 bar, methane-driven hydrological cycle, and lakes and rivers are vaguely similar to our Earthly home. The European-created Huygens probe, carried by the Cassini spacecraft, arrived on Titan’s surface in January 2005 [1]. Upon landing, Huygens photographed its landing site, as seen in Figure 1. The photo depicts rock like objects, thought to be comprised of water ice sitting in a dry …

Examining Denitrification In Agricultural Ditch Sediments Vegetated With Rice Cutgrass (Leersia Oryzoides): Modeling Seasonal Variation Across Increasing Levels Of Nitrate Loading And Model Application To Pre-Existing Datasets, Shannon Lee Speir

Graduate Theses and Dissertations

Nitrogen (N) derived from fertilizer application in agricultural systems may contribute to significant environmental impacts, including eutrophication of fresh and coastal waters. Rice cutgrass (Leersia oryzoides) can significantly enhance denitrification potential in agricultural ditch sediments, but relationships with known drivers are not well understood. To address this, I examined effects of nitrate (NO3-) availability on dinitrogen gas (N2) and NO3- fluxes seasonally in Chapter 2. Denitrification rates were measured as N2 flux from intact vegetated sediment cores using Membrane Inlet Mass Spectrometry (MIMS). Michaelis-Menten models were developed from observations to mathematically describe N2 fluxes across the spring, summer, and fall …

Liming Characteristics Of A High-Calcium, Dry Flue Gas Desulfurization By-Product And Its Effects On Runoff Water Quality, Jason Richard Burgess-Conforti

Graduate Theses and Dissertations

In 2013, only 37% of the 32 million Mg of flue gas desulfurization (FGD) by-products generated in the United States were reused beneficially. If FGD by-products could be used as a beneficial soil amendment, millions of megagrams may be diverted away from surface impoundments and landfills. The purpose of this research was to identify the liming characteristics of a high-Ca dry FGD (DFGD) by-product in comparison to a Class-C fly ash (FA) and reagent-grade CaCO3, and to evaluate the effects of land application to a managed grassland on runoff, plant, and soil quality. Liming characteristics were determined by measuring the …

Growth Of Methanogens In The Presence Of Perchlorate Salts: A Study For Possible Life On Mars, John Cale

Biological Sciences Undergraduate Honors Theses

The Phoenix Lander collected soil samples from Mars, and it detected perchlorate salts in its analysis [1]. As oxidizing agents, perchlorates pose a threat to the hypothesis that there may be microbial life on Mars. Since Mars is very dry, perchlorate may continue to accumulate in the soil. If anaerobic methanogens inhabit Mars, then they must be able to grow in the presence of perchlorate salts. There were four species of methanogens tested in this project. The methanogens were first exposed to small concentrations of calcium perchlorate, and then they were gradually tested at higher concentrations. Growth was measured by …

Stratigraphy And Structure Of A South-Trending Structural High, Northern Arkoma Basin, Arkansas, Yirong Chen

Graduate Theses and Dissertations

The Arkoma Basin is a Carboniferous peripheral foreland basin in southeastern Oklahoma and west-central Arkansas. The formation of the Arkoma Basin is a result of a collision between the North American Plate and the Sabine Terrane. To the north of the basin, there is a structural high that extends southward from the Arkoma Shelf into the basin. This structure is in contrast with the prevailing east-trending strike of structures in the northern margin of the basin and is poorly defined. This paper examined the structure of the salient with stratigraphic and structural cross sections. Across the study area, two NS …

Determination Of Optimum Fall And Spring Nitrogen Fertilizer Rate For Maximizing Grain Yield Of Soft Red Winter Wheat Sown At Variable Planting Dates, Lucas Vasconcelos Vieira

Graduate Theses and Dissertations

An optimum planting date is important for winter wheat nitrogen (N) management as it dramatically changes the growing environment including temperature and moisture, ultimately affecting fertilizer efficiency and grain yield (GY). In Arkansas, high precipitation in the fall often forces farmers to delay planting and current Arkansas recommendations include the application of fall N when soft red winter wheat (SRWW) is sown later than optimum, despite the lack of data supporting this practice. This study evaluated the effect of rate and timing of N application on GY of SRWW sown at variable planting dates in Arkansas. Granular urea was split …

Initial Structural Subsidence As Reflected In Morrowan And Atokan (Pennsylvanian) Subsurface Stratigraphy, Northern Arkoma Basin, North-Central Arkansas, Fatimah Taher Nahi Al Asadi

Graduate Theses and Dissertations

The Arkoma Basin is a carboniferous foreland basin that is known for its prolific gas production. The objective of this research is to study the initial subsidence of the basin by analyzing the strati-graphic and structural features of the study area. This was accomplished through IHS Petra, Surf-er 13, and Win-Tensor software. Field work studies comprised a large part of this study. Also, a seismic profile and Google earth elevation profiles are among the methods used to study the initial subsidence of the Arkoma Basin. The study area within the basin represents a transitional zone from the shelf into the …

Implications For The North American Lower Crustal 7.Xx Km/S Layer From An Exhumed Crustal Root, Western Canadian Shield, Calvin Everette Johnson

Graduate Theses and Dissertations

Studies of the Thorsby magnetic low, the southern extent of the 2,800 km-long Snowbird

Tectonic Zone (STZ) in Alberta, Canada, show pronounced lower crustal seismic reflectivity and preservation of a crustal root. These features may be correlative to the well-exposed central STZ, where two lower crustal tectonic events have been identified at 2.6-2.55 Ga and 1.92-1.89 Ga. High-resolution cross-sections of the central STZ reveal the late-stage interaction of Paleoproterozoic intracontinental thrust and strike-slip shear zones responsible for juxtaposing ca. >20,000 km2 of lower continental crust (0.9-1.5 GPa) with middle continental crust (0.5 GPa) (Mahan and Williams, 2005; Dumond et al., …

3d Seismic Interpretation Of Paleokarst Sinkholes, Boone Limestone, Lower Mississippian: Subsurface Eastern Arkoma Basin, Conway County, Arkansas, Daniel James Moser

Graduate Theses and Dissertations

Unconventional natural gas discoveries in the Fayetteville Shale of the eastern Arkoma Basin have led to improved understanding of subsurface geology in central Arkansas. This study interprets 3D seismic data for evidence of paleokarst within the Mississippian formations in a portion of the subsurface of Conway County, Arkansas. Quantitative data interpretation suggests that sinkholes developed during the Mississippian portion of the eastern Arkoma Basin record.

In a nine square mile area, 3D seismic mapping of Mississippian formations show 14 closed depressions interpreted as karst sinkholes. Time and depth structure maps were created and utilized to estimate the timing of dissolution …

Early And Middle Atokan Lithostratigraphy And Reservoir Development, Northern Arkoma Basin, Northwestern Arkansas, Matthew Alan Blaylock

Graduate Theses and Dissertations

The Arkoma Basin is a peripheral foreland arc basin associated with the Ouachita orogenic belt. In Arkansas, the basin is bounded by the Ouachita belt to the south and the Ozark Dome to the north. Sedimentary rocks of early to middle Atokan age are present in the shallow subsurface at the northern margin of the Arkoma Basin in northwestern Arkansas. Sedimentary units of this time interval reflect basinal subsidence, and the transition of the Arkoma Basin from a passive margin shelf to a rapidly evolving foreland arc basin. Sediment sources from the north and east produced a thickened Lower and …

Validation Of N-Star Nitrogen Rate Recommendations And Evaluation Of N-Star Soil Sampling Procedures For Clay Soils In Arkansas, Jarom Thane Davidson

Graduate Theses and Dissertations

The two methods for determining N-fertilizer recommendations for rice (Oryza sativa L.) in Arkansas are the standard N recommendation (SR) based on soil texture, previous crop, and rice cultivar, and the Nitrogen-Soil Test for Rice (N-STaR) which quantifies the potentially mineralizable-N of the soil and provides a site-specific N recommendation. The N-STaR program has recently been developed, and the validation of N-STaR for clay soils is an important step in ensuring that N-STaR predicts correct N-fertilizer rates for rice under a delayed-flood production system. Small-plot trials located across Arkansas compared the N-STaR 95 and 100% relative grain yield (RGY) N …

Optical Water Quality And Human Perceptions Of Rivers, Amie West

Graduate Theses and Dissertations

Understanding water quality dynamics in recreational rivers is integral in shaping management strategies that maintain ecosystem health, perceived value and appeal, and regional economic significance in a changing environment. Optical water quality describes the behavior of light in water as governed by its physical and chemical composition, and is among the strongest influences on human perceptions of water quality. Ethnohydrology is the study of culturally constructed knowledge and understanding of water. This work is the culmination of an interdisciplinary approach to water resources research—integrating optical water quality and ethnohydrology methods to recognize the intersection between measured water quality and visible …

Chlorine Demand Shows Thresholds And Hierarchy With Source Water Quality At Beaver Lake, Arkansas, Jaime M. Gile

Graduate Theses and Dissertations

This study investigated the effects of source water quality in Beaver Lake on the amount of chlorine (Cl) needed to develop decision support system to help guide chlorination practices in pre-treatment of source water. Chlorine demand assays were performed on water samples from Beaver Lake collected from the intake structure at Beaver Water District from March 2014 through August 2015, and using data from these assays, the two points of interest in this study were the Cl dose at which Cl residuals began to accumulate and the mean Cl demand occurring after that dose. Three methods of analysis were used …

Do Limestone Quarries Act As “Engineered Sinkholes”? Analysis Of Exfiltration Of Groundwater From Limestone Quarries In The Boone Formation, Ozark Physiographic Province, Arkansas, Usa, Noel Turner

Graduate Theses and Dissertations

Limestone quarries are a source of construction materials that are utilized in our everyday lives. Karst landscapes cover up to 15 percent of the Earth’s surface, and limestone quarries are found in these environmentally sensitive regions where groundwater and surface-water interactions are dynamic and complex. Several studies have provided conceptual models of groundwater flow to and out of quarries. The goal of this research was to describe the geochemistry of water exfiltration from limestone quarries in karst regions via joints, fractures, faulting, or karst features and to determine if limestone quarries are “engineered sinkholes”; that is to say: did quarries, …

Evaluating A Measure-Calculate Method For Determining Sediment Oxygen Demand In Lakes, Adrian Beirise

Graduate Theses and Dissertations

A steady-state mass diffusion model used with simple measurable and calculable inputs for determining sediment oxygen demand (SOD) is compared to an intact core incubation (ICI) SOD method using samples from three lakes. The mass diffusion model coupled with inputs is known as the measure-calculate method (M-C) and is a potential alternative to existing methods for measuring SOD which are more complex, time-consuming, and costly. The M-C method requires inputs for volumetric sediment oxygen uptake (Ṅsed), sediment density and porosity, and water properties. Ṅsed was determined by suspending sediment in oxygen-saturated water with a DO probe and determining the steady …

The Role Of Organic Matter In The Fate And Transport Of Antibiotic Resistance, Metals, And Nutrients In The Karst Of Northwest Arkansas, Victor Lee Roland Ii

Graduate Theses and Dissertations

Organic matter (OM) in the environment acts as a nutrient, but may also act as a transport vector for harmful chemical compounds and bacteria. Acetate is a labile form of OM produced during fermentation in anaerobic lagoons used to store animal fecal-waste from concentrated animal feeding operations (CAFOs). Dry and liquid fertilizers from CAFOs pose a threat to groundwater by introducing excessive amounts of nutrients (e.g. OM, nitrate and ammonia), metals, and antibiotic compounds. In the epikarst of Northern Arkansas in the Buffalo River watershed additional input of labile dissolved organic carbon (DOC) from liquid CAFO waste-fertilizers was hypothesized to …

Isotopic Identification Of Multiple Contributors Of Metal Ions In Mississippi Valley-Type Ore Deposits Along The Cincinnati Arch In South-Central Kentucky, William Travis Garmon

Graduate Theses and Dissertations

Mississippi Valley-Type (MVT) ores are economically-viable deposits of sulfide minerals, often dominated by sphalerite (zinc-sulfide) in carbonate facies, and galena (lead-sulfide) in siliciclastic facies. MVT ores precipitate from migrating fluids, which carry base metals often complexed with chlorine ions within a basinal brine. This study identifies metal-contributing source-regions of the Burkesville MVT deposit using Pb-isotope ratios within sphalerite samples collected from the Burkesville deposit. The deposit is found in south-central Kentucky within the Middle-Tennessee ore district along the crest of the Cincinnati Arch, which is the anticlinal divide between the Appalachian Basin and the Illinois Basin. Competing theories argue that …

Evaluation Of Rusle 2 To Estimate Soil Loss From Pastures, Stasha Katrina Balkissoon

Graduate Theses and Dissertations

The accurate estimation of soil erosion by the Revised Universal Soil Loss Equation version 2 (RUSLE2) is critical for several conservation assessments, least of which is its use in the Phosphorus Index (PI) to identify and rank the vulnerability of agricultural fields to phosphorus (P) runoff. Earlier versions of RUSLE reported a soil loss overestimation, which were revised to give RUSLE2, where biomass production in different climatic regions was more accurately represented. RUSLE version 2.0, which contains the new vegetative biomass production routine, was evaluated using two performance indices, the Nash Sutcliffe Efficiency Index (NSE) and Index of Agreement (D) …

Linear Trend Analysis: Implications For A Structural Fracture System And Applications Of Subsurface Fluid Migration, Northwest Arkansas And Eastern Oklahoma, Loren Labusch

Graduate Theses and Dissertations

Lineaments are mappable, simple or composite linear or curvilinear features of the Earth’s surface longer than one mile, which differ from the patterns of adjacent features and are presumed to reflect subsurface phenomenon such as faults and fractures. The usage of the term refers to the description Lattman published in 1958 and was the foundation for work by MacDonald in 1977, which is the basis for this project. Remote sensing techniques have provided a valuable means to analyze lineaments on a large scale in a relatively short time in comparison to field mapping methods. The products of such fracture studies …

A Geochemical Analysis Of The Arkansas Novaculite And Comparison To The Siliceous Deposits Of The Boone Formation, John Byron Scott Philbrick

Graduate Theses and Dissertations

Geochemical analyses of the Arkansas Novaculite, located within core structures of the Ouachita Mountains in west-central Arkansas, and penecontemporaneous chert of the lower Boone Formation, located atop the Springfield Plateau of southwest Missouri, northwest Arkansas, and northeast Oklahoma, have identified a significant concentration of both aluminum and potassium. This would seem to eliminate a biogenic origin and favor a volcanic source of the silica that comprises these units. Trace and rare earth element (REE) analysis also suggests that the Arkansas Novaculite and the chert in the lower Boone Formation may have both been formed from the same volcanic source.

The …

Statistical Analysis Of Fluvial Channel Belts, Kyle Ryan Spencer

Graduate Theses and Dissertations

As meandering rivers laterally migrate over time, they build channel belts. The accumulation of all previous flow paths creates the channel belt. To better understand these ancient rivers, modern river systems are being mapped to find statistical relationships between current flow path and the channel belt of river systems. It is important to examine a wide range of systems in terms of age, size, and location. The rivers are being mapped using an ImageJ, interpretations from Saucier (1994) and Google Earth. Three channel belt morphologies are mapped for 15 modern channel belts; the width of the river in relation to …

Investigating Mineral Stability Under Venus Conditions: A Focus On The Venus Radar Anomalies, Erika Kohler

Graduate Theses and Dissertations

Radar studies of the surface of Venus have identified regions with high radar reflectivity concentrated in the Venusian highlands: between 2.5 and 4.75 km above a planetary radius of 6051 km, though it varies with latitude. Previous research has proposed several theories on the source of these anomalies, including increased surface roughness, metallic materials with higher dielectric constants, or ferroelectric materials. Prior work suggests several processes that could be the origin of these anomalies, such as surface-atmospheric interactions or low lying clouds or fog. Alternatively, these anomalies could result from a semi-metallic compound trapped at the cooler conditions in the …