Digital Commons Network^™

Analysis Of Conjugate Heat Transfer In Tube-In-Block Heat Exchangers For Some Engineering Applications, Abdullatif Abdulhadi Gari

USF Tampa Graduate Theses and Dissertations

This project studied the effect of different parameters on the conjugate heat transfer in tube-in-block heat exchangers for various engineering applications. These included magnetic coolers (or heaters) associated with a magnetic refrigeration system, high heat flux coolers for electronic equipment, and hydronic snow melting system embedded in concrete slabs. The results of this research will help in designing the cooling/heating systems and select their appropriate geometrical dimensions and material for specific applications. Types of problems studied in this project are: steady state circular microchannels with heat source in the gadolinium substrate, transient heat transfer in circular microchannels with time varying …

Chemical Investigation Of Two Antarctic Invertebrates, Synoicum Adareanum (Chordata: Ascidiaceae: Enterogona:Polyclinidae) And AustrodorisKergulenensis (Molusca: Gastropoda:Nudibranchia: Dorididae), Thushara Kelum Kaviraj Diyabalanage

USF Tampa Graduate Theses and Dissertations

Synoicum adareanum is a colonial tunicate commonly found on the benthos around Palmer Station on Anvers Island, Antarctica. A comprehensive chemical investigation of the lipophilic extract of the frozen tunicates gave a new series of polyketide macrolides, palmerolides A-E and H. The structure elucidation of these compounds was accomplished by extensive NMR and mass spectral studies.The palmerolides are unusual 20-membered macrolides displaying functionality more commonly found in sponges or cyanobacteria. Palmerolide A, the major member of the group, shows significant and selective in vitro cytotoxicity against melanoma with three orders of greater sensitivity relative to other cell lines tested, in …

Fuzzy Logic In Process Control: A New Fuzzy Logic Controller And An Improved Fuzzy-Internal Model Controller, Yohn E. Garcã­A Z.

USF Tampa Graduate Theses and Dissertations

Two fuzzy controllers are presented. A fuzzy controller with intermediate variable designed for cascade control purposes is presented as the FCIV controller. An intermediate variable and a new set of fuzzy logic rules are added to a conventional Fuzzy Logic Controller (FLC) to build the Fuzzy Controller with Intermediate Variable (FCIV). The new controller was tested in the control of a nonlinear chemical process, and its performance was compared to several other controllers. The FCIV shows the best control performance regarding stability and robustness. The new controller also has an acceptable performance when noise is added to the sensor signal. …

An Attributional Analysis Of Counterproductive Work Behavior (Cwb) In Response To Occupational Stress, Angeline Goh

USF Tampa Graduate Theses and Dissertations

The purpose of this study was to investigate the influence of hostile attribution style (HAS) on the processes linking job stressors and CWB. Self and peer data were collected via online questionnaires from employed participants recruited from undergraduate classes and non-student employees. Using data from 147 dyads of employees and coworkers, the effects of HAS on three areas were examined: the influence of HAS on the appraisal of psychosocial (incivility, interactional justice, and interpersonal conflict) and nonsocial (organizational constraints and workload) stressors; HAS as a moderator of the link between stressors and CWB; and HAS as mediator of the link …

Alcohol Expectancy Cognitions: Psychophysiological Perspective, Inna Fishman

USF Tampa Graduate Theses and Dissertations

Considerable evidence indicates that the expectations individuals hold about the effects of alcohol determine, to a degree, the amount of alcohol they drink. However, the bulk of this evidence was acquired using verbally-based measures of expectancy. The present study sought to extend the validation network by utilizing an electrophysiological measure -- the P300 component of the Event Related Potentials (ERPs) --

which is thought to index fundamental neurophysiological processes sensitive to expectancy.Previous research has demonstrated that, when presented with various outcomes of alcohol consumption, heavier drinkers endorse statements that assert positive and arousing effects of alcohol, while lighter drinkers endorse …

An Instrumental Case Study Of The Phenomenon Of Collaboration In The Process Of Improving Community College Developmental Reading And Writing Instruction, Patricia C. Gordin

USF Tampa Graduate Theses and Dissertations

Focusing upon the intersections between community college faculty and assessment professionals (e.g., institutional researchers) in improving student learning outcomes, the purpose of this study was to describe, analyze, and interpret the experiences of these professionals as they planned for and conducted student learning outcomes assessment in developmental reading, writing, and study skills courses. This instrumental case study at one particular community college in Florida investigated the roles played by these individuals within the larger college effort to develop a Quality Enhancement Plan (QEP), an essential component of a regional accreditation review. The methodology included individual interviews, a focus group interview, …

An Investigation Of The Effects Of Perceived Feedback Accuracy On Performance, Ashley A. Gray

USF Tampa Graduate Theses and Dissertations

This study built upon the theoretical feedback process of Ilgen, Fisher and Taylor (1979), as refined by Kinicki, Prussia, Wu, & Mckee-Ryan (2004), to contribute to a more comprehensive understanding of the mechanism underlying an individual's response to performance feedback. The feedback model implicates source credibility and the feedback-rich environment as critical elements in the process explaining recipient accuracy perceptions and responses. Thus the sign and perceived accuracy of performance feedback were investigated in a 3 x 3 (plus control) experimental design. One hundred fifty-six undergraduate students were randomly assigned to feedback conditions, in which they performed on a three-trial …

Calling All Learners: An Explanatory Integrative Research Study Of Efl Learner-Learner Corrective Feedback Patterns Within On-Line Synchronous Environments, Annmarie Gorenc Zoran

USF Tampa Graduate Theses and Dissertations

This mixed methods research study centers on learner-learner interactions; thus, contributing to the on-going investigation within negotiation and interaction, computer-mediated-communication and its role in second language learning. The specific aim was to investigate corrective feedback types, incidences, and the relationship between error and feedback type among peers within online synchronous environments in EFL classes in Slovenia, Europe. Interactional characteristics of corrective feedback with learners having a documented special need (SN) also were explored using qualitative analyses. The study encompassed 208 students that were randomly placed into 104 dyads within intact classes of Grades 7, 8, 10, and 11. There were …

Development Of A Microsphere-Based Immunoassay For The Detection Of Igm Antibodies To West Nile Virus And St. Louis Encephalitis Virus In Sentinel Chicken Sera, Logan C. Haller

USF Tampa Graduate Theses and Dissertations

West Nile virus (WNV) and St. Louis Encephalitis (SLEV) are arthropod-borne viruses belonging to the genus Flavivirus and are classified as significant human pathogens of global epidemiological importance. Since its introduction into the United States in 1999, WNV has spread throughout most of the country and has caused major epidemics of neuroinvasive disease (Hayes and Gubler, 2005). SLEV is endemic to the United States and is maintained in an enzootic transmission cycle in Florida.The Florida Sentinel Chicken Arboviral Surveillance Network was established in 1978 following a widespread rural epidemic of SLEV in central Florida to monitor the activity of arboviruses …

Modulation Of Neural Plasticity By The Adamtss (A Disintegrin And Metalloproteinase With Thrombospondin Motifs), Michelle Grace Hamel

USF Tampa Graduate Theses and Dissertations

Aggregating proteoglycans (PG) bearing chondroitin sulfate (CS) side chains are well-known inhibitors of neural plasticity and associate with hyaluronan and tenascin-R to form a complex of extracellular matrix (ECM) in the central nervous system (CNS). Little is known about whether proteolytic cleavage of the core protein affects neural plasticity. Several members of the ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) family of metalloproteinases are glutamyl-endopeptidases that cleave aggregating PGs. Our initial studies determined that neural cultures secrete a brevican-containing matrix, and that these neural cultures also produced ADAMTS4, a protease that cleaves brevican. Furthermore, this brevican-containing matrix in astrocytes …

Effect Of Alkalis And Sulfate On Portland Cement Systems, Mahmoud Halaweh

USF Tampa Graduate Theses and Dissertations

The effect of the sulfates and alkalis on the durability of Portland cement systems was investigated through a series of cube and prism mixes. Durability was assessed using expansion of mortar prisms and the compressive strength of mortar cubes. The study covered a large range of both alkali and sulfate contents using 5 different Portland cements. The alkali contents ranged from 0.27 to 3.8%, the sulfate content (as SO3) ranged from 2.54 to 5%. Doping was done using Terra Alba gypsum and potassium hydroxide. In addition to physical measurements, SEM, XRD, chemical analysis and heat of hydration calorimetry were used …

Realism, Sovereignty, And International Relations: An Examination Of Power Politics In The Age Of Globalization, Tyler Harrison

USF Tampa Graduate Theses and Dissertations

Many globalization theorists make the claim that the state, in its current Westphalian context, is no longer a viable unit of analysis in comparative politics or international relations. Globalists claim that in the wake of unprecedented, global integration, the state is either in retreat or on the verge of full scale extinction. In a general sense, this paper explores whether there is a sufficient amount of evidence to supports the claims of globalists that the state is dying. Moreover, the paper looks at the specific issue areas of international trade, multilateralism and the environment to determine what effects globalization has …

Evaluating The Reliability Of Continuous Resistivity Profiling To Detect Submarine Groundwater Discharge In A Shallow Marine Environment: Sarasota Bay, Florida, Arnell Harrison

USF Tampa Graduate Theses and Dissertations

Submarine groundwater discharge (SGD) can be an important pathway for nutrients entering coastal systems. However SGD flow paths can be difficult to identify and flow volumes difficult to quantify. This study assesses whether geophysical techniques are potentially cost effective methods for detecting the presence or lack of SGD within an estuary environment found in Sarasota Bay, Florida. In this area, a rapid increase in urbanization has led to increased nitrogen loading into the bay, with some 10% of this loading attributed to SGD. Discharging groundwater is expected to be fresher and hence higher resistivity, than "background" surface waters. Thus resistivity …

The Early Time Course Of Smoking Withdrawal Symptoms, Peter Schuyler Hendricks

USF Tampa Graduate Theses and Dissertations

Despite the large volume of research on tobacco withdrawal, the vast majority of studies have focused on the onset and remission of symptoms over the course of several days and weeks, with the earliest assessment periods occurring the day after cessation. To date, there has been no systematic study of the very early time course of the tobacco withdrawal syndrome, despite its obvious relevance to the maintenance of both smoking and postcessation abstinence. The published literature contains a range of estimates about the early appearance of withdrawal symptoms, but without reference to empirical data. The main objective of the current …

Ferrite-Ferroelectric Thin Films With Tunable Electrical And Magnetic Properties, Ranko Heindl

USF Tampa Graduate Theses and Dissertations

A growing need for developing new multi-functional materials operating at microwave frequencies is demanding a better understanding of ferroelectric and ferrimagnetic materials and their combinations. Some of these materials exhibit tunable physical properties, giving an extra degree of freedom in the device design. New multifunctional ferroelectric and ferrimagnetic thin film structures are investigated in this dissertation research, in which dielectric and magnetic properties can separately be tuned over a certain frequency range. The materials of choice, Ba0.5Sr0.5TiO3 (BST) and BaFe12O19 (BaM), both well studied and used in many microwave applications, were prepared using rf magnetron sputtering and pulsed laser ablation. …

Brain-Compatible Research: Using Brain-Based Techniques To Positively Impact Student Learning, Laurie A. Herson

USF Tampa Graduate Theses and Dissertations

This thesis discusses brain-based methodology and how educators can use brain-based techniques to impact, support, and advance cognitive growth. Current research on learning and memory is enabling educators to better understand how the brain learns and what environmental factors assist in or detract from student learning. Brain-based learning techniques are considered by brain-based researchers as one way to create a learning environment that fosters student learning at individual academic levels while concurrently challenging each student and promoting academic growth. Teachers can further student academic advancement through the direct manipulation of the classroom environment rather than by purchasing a particular program …

Strategic Geographic Positioning Of Sea Level Gauges To Aid In Early Detection Of Tsunamis In The Intra-Americas Sea, Joshua I. Henson

USF Tampa Graduate Theses and Dissertations

A tsunami is a series of large amplitude, shallow water waves generated by an event capable of displacing a massive volume of water. The displaced water propagates at speeds in excess of 800 kph until it dissipates or impacts a shoreline where it slows to 30 --

50 kph [NOAA and USGS Fact Sheet, 2005]. Earthquakes are the predominant tsunamigenic event, however, landslides, avalanches, submarine slumps or slides, volcanic eruptions, volcano flank failure, and meteor impact into an ocean can also cause a tsunami [McCann, 2004; O'Loughlin and Lander, 2003; Pararas-Carayannis, 2004]. This study includes past Caribbean tsunamigenic events assumed …

Confronting College: Foster Care Youth Deciding Whether To Participate In Higher Education Programs, Linda K. Herlocker

USF Tampa Graduate Theses and Dissertations

This study's purpose was to explore the college choice process for foster care youth who are aging out of Florida's protective services system. The research methodology included three components. First, a survey of the Independent Living Coordinators throughout the state of Florida solicited data regarding participation rates and enrollment patterns among foster care youth. Next, in a meeting setting, a survey was administered to foster care youth, probing the extent to which they considered certain college choice decision factors. Finally, upon completion of the survey, participants remained for a guided focus group discussion to further explore their decision criteria.The results …

The Karst Of West-Central Florida, Lee John Florea

USF Tampa Graduate Theses and Dissertations

Caves, the cornerstone feature of karst aquifers, are little understood in Florida. This dissertation, which analyzes the morphology, elevation, lithologic setting, and hydrology of caves in west-central Florida, demonstrates that the karst of the unconfined Floridan aquifer differs from the paradigm view of karst presented in modern geology textbooks. The differences reflect setting: eogenetic (west-central Florida) vs. telogenetic (conventional). Interpretations about the architecture of cavernous porosity in this dissertation come from detailed surveys (497 stations) of seven air-filled caves.The surveys reveal that solution cavities within the unconfined Floridan aquifer align along NE-SW and NW-SE fractures. The surveys further identify tabular …

Improving Prostate Cancer Detection In Veterans Through The Development Of A Clinical Decision Rule For Prostate Biopsy, Owen T. Hill

USF Tampa Graduate Theses and Dissertations

In the U.S., the number of prostate biopsies increases annually. This is partly due to elevated prostate specific antigen (PSA) values identified during PC screening. This study's goal was improving prostate cancer (PC) detection through developing a clinical decision rule (CDR), based on an elevated PSA and laboratory biomarkers. This decision rule could be used after an elevated PSA, providing the patient and clinician information to consider prior to biopsy. This cross-sectional study evaluated men from the Tampa, Florida, James A. Haley (JH) VA (N=1,378), from January 1, 1998, through April 15, 2005. The study hypothesized that specific lab biomarkers …

Abrupt Climate Change During The Last Glacial Period: A Gulf Of Mexico Perspective, Heather W. Hill

USF Tampa Graduate Theses and Dissertations

Understanding the cause of abrupt climate change in the geologic past can help assess the potential magnitude and variability of future changes in regional and global climate. The research presented here focuses on some of the first records of hydrologic variability in the central North American continent during an interval of Marine Isotope Stage 3 (24-57 thousand years before present (ka)). Sediment core MD02-2551 from the Orca Basin, northern Gulf of Mexico, is used to document the first detailed melting history of the southern margin of the Laurentide Ice Sheet (LIS) during MIS 3, and to record terrestrial inputs from …

Gold Mining In A Tropical Rainforest: Mercury Sorption To Soils In The Mining Region Of Arakaka-Matthew's Ridge, Guyana, Joniqua A'Ja Howard

USF Tampa Graduate Theses and Dissertations

Gold mining by artisinal (small-medium scale) miners causes an immense amount of damage to the environment (i.e. soil erosion, mobilization of heavy metals, etc.).1, 2 One of the most popular gold mining techniques employed by artisinal miners in Guyana is mercury amalgamation. During the amalgamation process approximately 300 metric tons/yr 11, 12 of mercury is used. Mercury once in the environment can be transported through the air, soil, and water column. It is estimated that 90-99% of total mercury (THg) is associated with the sediment. An understanding of the geochemical conditions that affect the fate of mercury in soils, which …

Development And Evaluation Of An Inertial Based Pavement Roughness Measuring System, Fengxuan Hu

USF Tampa Graduate Theses and Dissertations

Roughness is an important indicator of pavement riding comfort and safety. It is a condition indicator that should be carefully considered when evaluating primary pavements. At the same time, the use of roughness measurements plays a critical role in the pavement management system.There are many devices used for roughness evaluation. The major tools used for road roughness quantify are the road profilers. In the thesis research, in order to obtain useful pavement surface condition data for pavement evaluation, an inertial based pavement roughness measuring system was developed with the combination of modern sensor technology and computer technology. The research will …

The Influence Of The “Book Of Job” On The Middle English Morality Plays, Cameron Hunt-Logan

USF Tampa Graduate Theses and Dissertations

The Book of Job was extremely popular in the Middle Ages, especially in England, because of its role in liturgy as well as lay religious devotion. I argue that the Book of Job was heavily influential in the writing of the medieval morality plays Castle of Perseverance, Mankind, Wisdom, and Everyman. In the plays, the dramatists mirrored many of Job's structural and artistic elements, creating direct parallels between the Biblical text and the morality plays. The authors also relied on Job's ideological framework to establish their own arguments, forming not only a textual but ideological linkage. Yet the most intriguing …

Salinity- And Temperature-Dependent Groundwater Flow In The Floridan Aquifer System Of South Florida, Joseph D. Hughes

USF Tampa Graduate Theses and Dissertations

Density-dependent groundwater flow in the Floridan aquifer system (FAS) depends on chloride concentrations and fluid temperature. Previous studies addressing the role of chloride concentration and temperatures on groundwater flow in the FAS have relied on observation data or simplified two-dimensional numerical models. A three-dimensional hydrologic analysis of FAS in peninsular Florida was performed using a modified version of SUTRA (SUTRA-MS) capable of simulating multi-species solute and heat transport. SUTRA-MS was developed during this investigation and is capable of reproducing results for several problems with known solutions.The model was developed using available geometric and hydraulic parameter data and calibrated using hydraulic …

Hollow-Electrode Pulsed Plasma Deposition Of Titanium And Carbon Thin Films, Robert H. Hyde

USF Tampa Graduate Theses and Dissertations

This thesis presents a study of a pulsed distributed arc plasma deposition method that has been developed to produce highly ionized pulsed plasma plumes of metallic species in the presence of a low-pressure inert or reactive gas glow discharge. A pulse-forming network (PFN) is used to form a transient electrical discharge in a hollow electrode which is triggered by two different methods; a pulsed CO2 laser or a pulsed high voltage glow discharge. With the PFN charged to a voltage of 70 - 100 VDC, current pulses with peak currents up to 3 kA and pulse widths as long 3.7 …

Kinematics Of Curved Flexible Beam, Saurabh Jagirdar

USF Tampa Graduate Theses and Dissertations

Compliant mechanism theory permits a procedure called rigidbody replacement, in which two or more rigid links of the mechanism are replaced by a compliant flexure with equivalent motion. Methods for designing flexure with equivalent motion to replace rigid links are detailed in Pseudo-Rigid-Body Models (PRBMs). Such models have previously been developed for planar mechanisms. This thesis develops the first PRBM for spherical mechanisms. In formulating this PRBM for a spherical mechanism, we begin by applying displacements are applied to a curved beam that cause it todeflect in a manner consistent with spherical kinematics. The motion of the beam is calculated …

Differential Coupling Of Rgs3s And Rgs4 To Gpcr-Girk Channel Signaling Complexes, Cristina Jaén

USF Tampa Graduate Theses and Dissertations

'Regulators of G protein signaling' (RGS proteins) modulate the G proteincycle by enhancing the GTPase activity of Ga subunits. These changesaccelerate the kinetics of ion channel modulation by Gai/o-coupled receptors(GPCRs) such as the G protein-gated inward rectifier K+ (GIRK/Kir3) channel. Myexperiments indicate that a single cerebellar granule (CG) neuron, a cell type thatendogenously expresses GIRK channels is able to express a wide variety ofRGS proteins. I selected two of them, which are widely expressed andtranscriptionally regulated during pathophysiologic conditions, to compare theirfunctional properties. I originally described the differential modulatory effects oftwo RGS proteins, the RGS3 short isoform (RGS3s) and RGS4, …

Tampa’S Lafayette Street Bridge: Building A New South City, Lucy D. Jones

USF Tampa Graduate Theses and Dissertations

The late nineteenth and early twentieth century was a time of dynamic social and political change for Tampa, a growing city on Florida's west coast. These changes led Tampa's commercial-civic elite to look beyond the law, the militia, and the church for ways to maintain their sense of order. This thesis illustrates non-violent enforcement of the status quo via public works, specifically bridge construction over the Hillsborough River. Over a period of three decades, three different bridges were built at the same place, at Lafayette Street. Each time the bridge was built or replaced, it was ostensibly for a different …

Effects Of A-Beta Immunotherapy And Omega-3 Fatty Acid Administration In Alzheimer’S Transgenic Mice, Maren T. Jensen

USF Tampa Graduate Theses and Dissertations

Major therapeutics against Alzheimer's disease (AD) are targeted towards reducing beta-amyloid in the brain and improving cognitive performance. Transgenic mouse models of AD have become critical in the development of such therapeutics to protect against or treat AD. This dissertation examined the potential protective effects of both active A-beta immunotherapy and dietary omega-3 fatty acid administration to AD transgenic mice. First, immunization with A-beta 1-42 from 2-16 1/2 months of age provided protection against cognitive impairment in APP/PS1 transgenic mice well into older age. At both adult (4 1/2-6 month) and aged (15-16 1/2 month) test points, an extensive 6-week …