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Subsurface Planetary Investigation Techniques And Their Role For Assessing Subsurface Planetary Composition, Ahmed Elshafie

Graduate Theses and Dissertations

Subsurface planetary investigation techniques are of high interest and importance for the scientific community. Not only they can enhance our knowledge of the history of planetary formation but also can lead to information about its future. Whether the investigation is being conducted remotely using imagers, radars or physically using penetrometers or drills, a pre-existed knowledge of the mechanical and electrical properties of the subsurface regolith should be acquired for better data interpretation and analysis. Therefore, the main objective of this work is to investigate the mechanical and electrical properties of planetary analogs, understand their role for assessing the subsurface structure …

Orbital Periodicities Reflected In Ancient Surfaces Of Our Solar System And The Implications For A Record Of Early Life, Dixie Lee Androes

Graduate Theses and Dissertations

Uniformitarian processes, governed by invariant physical laws, remain the most reliable source for reconstructing the past. Driving many of the repetitive, predictable processes are the orbital dynamics of the Sun-Planet-Moon systems. Astronomical periodicities range from a few hours (tides) to thousands of years (Milankovitch). These periodicities, combined with geomorphic observations of planetary surfaces, constrain the time-dependent processes and allow for reconstruction of events and conditions favorable for sedimentary accumulations. This research suggests that seasonal sedimentary processes are dominant on Titan and Mars, and have played a significant role in the formation of ancient banded-iron formations (BIF's) on Earth.

Earth, Mars, …

Outcrop Investigation Of The Reeds Spring (Boone, Mississippian) Of The Hindsville Quarry Using Terrestrial Lidar, Terryl Glenn Daniels

Graduate Theses and Dissertations

In northern Oklahoma and southern Kansas the Reeds Springs Formation (Boone, Mississippian) is a hydrocarbon exploration objective (Mazullo et al, 2011). The Hindsville quarry located in the northeastern portion of Washington County in Arkansas is the focus of this study. The objective of this study is to characterize the Reeds Spring at the Hindsville Quarry. The use of terrestrial light detecting and ranging(LiDAR) is used to assist in the characterization of the quarry.

The unit architecture within the Hindsville Quarry outlines varying transitional periods that give insight into the deposition of the Reeds Springs Formation. There are comparable formations within …

The Silent Arms Race: The Role Of The Supercomputer During The Cold War, 1947-1963, David Warren Kirsch

Graduate Theses and Dissertations

One of the central features of the Cold War is the "Arms Race." The United States and the Union of Soviet Socialist republics vied for supremacy over the globe for a fifty-year period in which there were several arms races; atomic weapons, thermonuclear weapons and various kinds of conventional weapons. However, there is another arms race that goes unsung during this period of history and that is in the area of supercomputing. The other types of arms races are taken for granted by historians and others, but the technological competition between the superpowers would have been impossible without the historically …

Sequence Stratigraphy And Depositional Systems Of The Mansfield Sand, Upper Atoka Formation, Arkoma Basin, Arkansas, Scott Cherry

Graduate Theses and Dissertations

The Mansfield sand is an informally named member of the Pennsylvanian Atoka Formation in Arkansas. Once a productive gas reservoir, the Mansfield is situated in a double plunging anticline in the southern portion of the Arkoma Basin. The formation is internally composed of sandstone units ranging in thickness from tens of feet to over a hundred feet interbedded with shale units ranging in thickness from several tens of feet to hundreds of feet. Previous studies have focused on the stratigraphy of the lower and middle Atoka. A detailed subsurface study of the stratigraphic framework of the Mansfield sand was conducted …

Dynamical Properties Of Ferroelectric Perovskites (Ba,Sr)Tio3 And Pb(Zr,Ti)O3 Systems From First Principles, Jeevaka Weerasinghe

Graduate Theses and Dissertations

A first-principles-based effective Hamiltonian scheme which incorporates coupling between ferroelectric (FE) and antiferrodistortive (AFD) motions is applied to Pb(Zr,Ti)O₃ alloys. It validates the existence of two modes of E symmetry (rather than the single E(1TO) soft mode) in the 50-75 cm^-1 range for temperatures smaller than 200 K and for compositions falling within the Rhombohedral R3c phase. Coupling between long-range-ordered FE and AFD motions is shown to be the cause of the additional mode and more insight into its nature is provided. This scheme is further used to reveal a field-induced anticrossing involving FE and AFD degrees of …

The Ipad As An Instructional Tool: An Examination Of Teacher Implementation Experiences, Brandie Kay Benton

Graduate Theses and Dissertations

At present, handheld devices and tablet computers are infiltrating public schools across the nation, the most popular model being the Apple iPad. Schools and teachers are attempting to integrate the devices and are using a variety of methods and models for implementation. The purpose of this study was to examine the implementation of the iPad as an instructional tool through the experiences of classroom teachers.A review of related literature was conducted to inform the conceptual framework, design, data collection, analysis, and synthesis components and stages of this study. Qualitative methods, including teacher-participant interviews and classroom observations, were utilized in this …

Stability Of Phyllosilicates On Mars, Patricia Gavin

Graduate Theses and Dissertations

This study investigates the stability of phyllosilicates on the surface of Mars through laboratory experiments and analysis of terrestrial analogs. Phyllosilicates are mostly found in the oldest Noachian terrains on Mars and hence hold clues to the planet's earliest aqueous and geologic history. Phyllosilicates relevant to Mars were heated up to ~1100°C for up to 24 hours and impacted with projectile velocities up to ~4.5 km/s. Heated samples were analyzed using x-ray diffraction (XRD) and Fourier Transform Infrared (FT-IR) spectroscopy in the near- (NIR, 1.0-2.5 µm) and mid-infrared (MIR, 5.0-15.0 µm) ranges. Impacted samples were also analyzed using Raman spectroscopy …

The Neglected Minority: Interviews With Successful Community College Students From Poverty, Heather Hollifield-Hoyle

Graduate Theses and Dissertations

Poverty in the US is growing at an alarming rate. The current economic climate demands higher education to embrace the economic diversity of all students and to prepare them, regardless of economic class, for a globally competitive workplace. Unfortunately, the higher education community is not as adept at serving low-income students, as it is middle- and upper- income students. Low-income students are less likely than their more affluent peers to enroll in college or graduate. Employing qualitative narrative methods, this dissertation explores the factors that contributed to the persistence and success of 18, low-income, community college students. This study addresses …

A Subsurface Stratigraphic Study Of The Middle Atoka, Sebastian County, Arkansas, Sara Beth Sutton

Graduate Theses and Dissertations

Raster log images were analyzed to study the subsurface stratigraphy of the Middle Atoka in the Arkoma Basin of the western portion (Sebastian County) of Arkansas. The most significant sandstone units of the Middle Atoka in this area were determined to be two generally coarsening-upward sequences in the lower portion of the formation. Based on lithologic correlations, these two units were determined to be the informally named Casey and Freiburg members of the Middle Atoka. Thickness information based on picked tops was used to create isopach maps of the units of interest. The log signatures and geometry of the sand …

Atomistic Simulations Of Defect Nucleation And Intralayer Fracture In Molybdenum Disulphide During Nanoindentation, James A. Stewart

Graduate Theses and Dissertations

Molybdenum disulphide (MoS2) is a layered, hexagonal crystal that has a very low coefficient of friction. Due to this low coefficient of friction, MoS2 has become a well-known solid lubricant and liquid lubricant additive. As such, nanoparticles of MoS2 have been proposed as an additive to traditional liquid lubricants to provide frictional properties that are sensitive to different temperature and pressure regimes. However, to properly design these MoS2 nanoparticles to be sensitive to different temperature and pressure regimes, it is necessary to understand the mechanical response of crystalline MoS2 under mechanical loading. Specifically, the fundamental mechanism associated with the nucleation …

Polarization Properties Of Maxwell-Gauss Laser Beams, Jessica Patricia Conry

Graduate Theses and Dissertations

Laser beams are wave-like optical disturbances. They are characterized by a dominant direction of propagation and a finite extent transverse to the direction of propagation. Many characteristics of laser beams can be described in terms of a scalar function multiplied by a constant vector, which can be real (for linear polarization) or complex (for elliptical polarization). The scalar function is a solution to the paraxial scalar wave equation. This scalar description, however, fails to describe the polarization and focusing characteristics of laser beams correctly. For a correct accounting of these characteristics, the electric and magnetic fields associated with laser beams …

The Inclusion Of The Nature Of Science And Its Elements In Recent Popular Science Writing For Adults And Young Adults, Feng Jiang

Graduate Theses and Dissertations

This study was conducted to examine the inclusion of nature of science (NOS) in popular science writing to determine whether it could serve supplementary resource for teaching NOS. Four groups of documents published from 2001 to 2010 were included in the analysis: Scientific American, Discover magazine, winners of the Royal Society Winton Prize for Science Books, and books listed in National Science Teacher Association's (NSTA) Outstanding Science Trade Books for Students K-12.

First, computer analysis was performed to categorize passages in the selected documents based on their inclusions of NOS. Then, follow-up human analysis was conducted to assess the frequency, …

The Relationship Between Middle Level School Science Programs And A Residential Environmental Learning Center, Ryan Mathew Walker

Graduate Theses and Dissertations

A multiple case study investigation examines the relationship between a residential environmental learning center and six schools that attend their program. Pre-experience interviews were conducted with teachers to gain understanding of how they integrate the residential experience with formal classroom instruction. On-site observations of teacher participation during the program provided insight into how they foster student learning during the experience. A student questionnaire was used to reveal students' perceptions of three areas of interest: 1) most meaningful aspects of the experience, 2) most confusing aspects of the experience and 3) topics they would like to know more about. These data …

Market Analysis Of Fresh Berries In The United States, Kristina Sobekova

Graduate Theses and Dissertations

This thesis contains a market analysis of fresh berries in United States. Specifically, it addresses strawberry, blueberry, blackberry and raspberry markets during 2008-2011. A double log model and the Almost Ideal Demand model are used to gain insight into the demand side of the market. An equilibrium displacement model is used to develop suggestions for producers and decision makers. The results demonstrate that retail demand for berry crops is elastic and that the different berries are substitutes for one another. The equilibrium displacement model is used to predict producer surplus changes to industry wide efforts aimed at both production efficiencies …

Modeling The Adoption Of Identification Standards Within The Healthcare Supply Chain, Angelica Burbano

Graduate Theses and Dissertations

The adoption of identification standards and its associated technology in the healthcare supply chain has been slow over the past twenty five years, despite the evidence of the benefits that can be achieved. The widespread use of identification standards in the form of barcode labeled medical products can contribute to the reduction of point of care errors and can increase the efficiency of healthcare supply chain related processes. This research is focused on the analysis of the adoption of identification standards in the healthcare supply chain with a particular focus on the healthcare provider adoption challenges. The research is divided …

Semiconductor Nanocrystals: From Quantum Dots To Quantum Disks, Zheng Li

Graduate Theses and Dissertations

The bottom-up colloidal synthesis opened up the possibility of finely tuning and tailoring the semiconductor nanocrystals. Numerous recipes were developed for the preparation of colloidal semiconductor nanocrystals, especially the traditional quantum dots. However, due to the lack of thorough understanding to those systems, the synthesis chemistry is still on the empirical level. CdS quantum dots synthesis in non-coordinating solvent were taken as a model system to investigate its molecular mechanism and formation process, ODE was identified as the reducing agent for the preparation of CdS nanocrystals, non-injection and low-temperature synthesis methods developed. In this model system, we not only proved …

Part I - A Study Of The Formation Of Carbenes By Elimination Of Α-Bromosilanes And Application Toward The Synthesis Of Transition Metal Complexed Quinone Methide Analogs. Part Ii - Development Of Novel 7-Membered Ring Carbene Ligands For Palladium Catalyzed Cross Coupling Reactions., Christian Michael Loeschel

Graduate Theses and Dissertations

In part I, we wish to report our approaches toward transition metal complexed ortho-quinone methide analogs. ortho-Quinone Methides are a class of highly reactive compounds with a wide range of chemical and biological applications. Previously, a stable iron complexed benzannulated 5-membered ring quinone methide analog was reported by Allison and Neal27. Herein, we report our approaches to improve the reactivity of that system by removing benzannulation as well as changing the metal from iron to manganese and rhenium.

Furthermore, a methodological study on generating carbenes under mild conditions by elimination of α-halosilanes and its application towards metal complexed quinone methide …

A Daily Temperature Record For Central Texas, 1896-2011, Matthew Kain Taylor

Graduate Theses and Dissertations

A continuous record of 882,693 daily maximum, minimum, and mean temperature measurements for seven weather stations in central Texas dating from August 1, 1896, to August 31, 2011, were screened and corrected for missing values and inhomogeneities. The resulting data were averaged to create a 115-year unbroken regional record of daily temperature for central Texas. This record indicates warming in daily, seasonal, and annual temperatures. Winter warm temperature extremes have increased over the period of record while warm temperature extremes during the summer months have remained largely unchanged. Summer heat wave days and the length of heat waves have increased …

A Reexamination Of The Eastern Collared Lizard (Crotaphytus Collaris Collaris) In Arkansas, Ashley A. Grimsley

Graduate Theses and Dissertations

Loss of suitable habitat is a threat to species worldwide. Habitat destruction, including loss, change, and fragmentation of habitat, is the leading cause of species extinction. Eastern collared lizards (Crotaphytus collaris collaris) are habitat specialists on glades. Both C. c. collaris and glade habitats are rare and of special concern in the state of Arkansas. Many glade populations have already been extirpated in the Ozarks of Arkansas and Missouri. Increasing knowledge of the distribution, habitat structure, and population dynamics of C. c. collaris is important to ensure the survival of this species in Arkansas.

A literature review of …

Multiliteracies In The Classroom: An Explanatory Sequential Mixed Methods Approach To Teachers' And Students' Perspectives Toward Integration Of Technology, Laura Janine Chitty

Graduate Theses and Dissertations

An increased number of students graduating from high school lack college and career readiness skills to earn credit in entry-level college courses or begin a career in an entry-level position. Many schools across America have prepared to address students' college and career readiness with the adoption of Common Core State Standards. Twenty-five teachers and 92 students participated in this dissertation study conducted at a high school (grades 10-12) in the southern United States. The purpose of this study was to describe and explain teachers' and students' perspectives toward the integration of technology that enhances multiliteracies in the classroom. An explanatory …

Ultra-Low Voltage Digital Circuits And Extreme Temperature Electronics Design, Aaron J. Arthurs

Graduate Theses and Dissertations

Certain applications require digital electronics to operate under extreme conditions e.g., large swings in ambient temperature, very low supply voltage, high radiation. Such applications include sensor networks, wearable electronics, unmanned aerial vehicles, spacecraft, and energyharvesting systems. This dissertation splits into two projects that study digital electronics supplied by ultra-low voltages and build an electronic system for extreme temperatures. The first project introduces techniques that improve circuit reliability at deep subthreshold voltages as well as determine the minimum required supply voltage. These techniques address digital electronic design at several levels: the physical process, gate design, and system architecture. This dissertation analyzes …

Time Waits For No One: Using Time As A Lens In Information Systems Research, Christopher M. Conway

Graduate Theses and Dissertations

Despite considerable research interest, IT projects still fail at a higher rate than other projects. Primary causes for these failures are relational, motivational, and scheduling issues on the team. Using the concept of time as a lens, the four essays in this dissertation examine how the ways that individuals and teams structure time can help explain these failures. The essays formulate the concept of temporal dissonance at the individual and team level, and explore how temporal dissonance causes negative consequences for IT workers and IT teams.

Essay one synthesizes temporal dissonance from concepts of temporal congruity and cognitive dissonance. It …

Water Quality Trends And Nutrient Loads For The Watershed Research And Education Center In Northwest Arkansas, 2009-2012, John Metrailer

Graduate Theses and Dissertations

Nitrogen, phosphorus, and sediment transport is a concern for Northwest Arkansas due to high exports through riverine discharge. Urban, agricultural, and pastured watersheds have been associated with increased N, P, and sediment concentrations when compared to forested catchments. The objective of this study was to evaluate discharge and nutrient loads associated with a small urban, agricultural (row crop), wetland influenced, and pasture/farmland sub-catchment within four ephemeral drainages and located at the Watershed Research and Education Center in Fayetteville, AR. Samples were collected during base flow conditions and periodic storm flow conditions from 2009-2012. Flow adjusted concentration trends were used to …

Reservoir Characterization And Outcrop Analog: The Osagean Reeds Spring Formation (Lower Boone), Western Osage And Eastern Kay County, Oklahoma, Taylor Friesenhahn

Graduate Theses and Dissertations

The Reeds Spring Formation (Osagean) is a member of the Lower Mississippian carbonate series developed on the Cherokee Platform Province of northeastern Oklahoma. On the western flank of the Ozark Dome, these rocks dip in a west-southwest direction into the subsurface where they are oil and gas reservoirs. A series of road cuts and surface exposures are cropped out in the tri-state area of northwest Arkansas, northeastern Oklahoma, and southwestern Missouri. Outcrop characteristics, including an abundant amount of nodular, anastomosing chert, generally finer-grained carbonate texture, and stratigraphic relationships provide an analog for its subsurface counterpart. Based on core description and …

A Domain Specific Model For Generating Etl Workflows From Business Intents, Wesley Deneke

Graduate Theses and Dissertations

Extract-Transform-Load (ETL) tools have provided organizations with the ability to build and maintain workflows (consisting of graphs of data transformation tasks) that can process the flood of digital data. Currently, however, the specification of ETL workflows is largely manual, human time intensive, and error prone. As these workflows become increasingly complex, the users that build and maintain them must retain an increasing amount of knowledge specific to how to produce solutions to business objectives using their domain's ETL workflow system. A program that can reduce the human time and expertise required to define such workflows, producing accurate ETL solutions with …

Single-Pass Drying Of Rough Rice Using Glass Transition Principles, George Owira Ondier

Graduate Theses and Dissertations

The objective of this research was to study the drying characteristics, milling quality, and functional properties of rough rice subjected to single-pass drying while controlling kernel material states. Drying experiments were conducted at 60, 70, and 80C and relative humidities ranging from 13 to 83%. High drying air relative humidities (greater than 63%) maintained both the kernel surface and core in a rubbery state during drying, whereas low drying air relative humidities caused rapid transitioning of the surface layers from a rubbery to a glassy state. Long-grain pureline cultivar, Wells, medium-grain pureline cultivar, Jupiter, and long-grain hybrid cultivar, CL XL729, …

Gain Of A Single Gas Electron Multiplier, Mythra Varun Nemallapudi

Graduate Theses and Dissertations

Gas Electron Multiplier (GEM) is a gaseous detector used in particle detection and is known for its high rate capability. Ever since its invention in 1997, GEM was applied in many areas and recently has been proposed to be installed in the CMS high η regions for upgrade at LHC, CERN. A complete understanding of the working and gain behaviour does not exist. GEM gain is influenced by charging up and this has been variedly interpreted in literature lacking consensus. I have attempted in this work through simulations and measurements to achieve a better understanding of single GEM gain and …

Livestock Production And Wildlife-Based Tourism: Articulating Land-Use And Policy Conflicts In The Okavango Delta Ramsar Site In Botswana, Nelson Kgamanyane Sello

Graduate Theses and Dissertations

The management of common pool resources and policy conflicts between livestock and wildlife, two land-use types that take place in the same geo-spatial area has been a subject of debate among scholars for decades. This conflict in policies has engendered in communities which are beneficiaries attitudes that are either negative towards wildlife or favorable depending on the benefits they derive from them. This research therefore set out to understand the conflicts in the management of the Okavango Delta Ramsar Site (ODRS) where the OD is situated. The study used the grounded theory to collect and analyze the data in the …

The Effects Of First-Year Students' Self-Perceptions Of Behaviors, Attitudes, And Aptitudes On Their First-To-Second-Year Persistence, Rebecca Jean Lambert

Graduate Theses and Dissertations

Student persistence continues to be a topic of much research and discussion in higher education. Based on Bean and Eaton's (2000) psychological theory of persistence for its theoretical framework, this study examined the effect of students' demographic and background characteristics and students' self-perceptions on their first-to-second-year persistence at a small, private, faith-based institution. Demographic and background characteristics examined were gender, race/ethnicity, first-generation college student status, high school GPA, and type of high school attended. Four constructs from the CIRP Freshman Survey were used to examine student self-perceptions: (a) Habits of the Mind, (b) Academic Self-concept, (c) Social Self-concept, and (d) …