Digital Commons Network^™

Characterization And Formation Of Particulate Nitrate In A Coastal Area, Melissa Cheryl Foster Evans

USF Tampa Graduate Theses and Dissertations

Particulate nitrates play important roles in the atmosphere. They consist mainly of NH₄NO₃ and NaNO₃, products from the reactions of gaseous HNO₃ with gaseous NH₃ and sea salt, respectively. The gas-to-particle phase conversion of nitrate changes its deposition characteristics and ultimately changes the transport and deposition rates of the locally produced species. Studies were conducted to develop background information on the particle concentrations and size distributions and the chemistry and kinetics behind the interactions.

The predominant nitrate species in the Tampa Bay area was identified as coarse mode NaNO₃. NH_{4 …}

Assessing The Reproducibility Of Coral-Based Climate Records: A Multi-Proxy Replication Test Using Three Porites Lutea Coral Heads From New Caledonia, Christie L. Stephans

USF Tampa Graduate Theses and Dissertations

Coral-based climate studies commonly use elemental ratios and stable isotopes of coral skeletons to address seawater temperature and hydrologic balance issues in the tropical surface oceans. Replication, or cross-checking, a standard technique used to assess the fidelity of proxy records in paleoclimatology has not been widely applied in coral-based climate studies, primarily because of the time and cost associated with generating multiple records from a single reef site. Modern and paleoclimate reconstructions based on a single proxy-coral record from a site may contain errors if individual corals from the same reef record different geochemical signals. In this study we perform …

Analysis Of Flow In A Spray Nozzle With Emphasis On Exiting Jet Free Surface, Ryan M. Mead

USF Tampa Graduate Theses and Dissertations

A conical nozzle with two separate inlets within its top plate is analyzed. One of the inlets is in the center of the top plate, which is free to rotate, whereas the other inlet is positioned away from the center. The fluid entering through the outer inlet slot causes the top plate of the nozzle to spin. Several fluids including FC-77, FC-72, FC-87, and Methanol running at different flow rates were investigated to observe the effect that their particular properties have on the geometry of the fluid's free surface exiting the nozzle. Another variation performed was the geometry of the …

Perceptions Of Family Functioning Between Children With Behavior Difficulties And Their Primary Caregiver, Melissa Farino Todd

USF Tampa Graduate Theses and Dissertations

This research study compared perceptions of family functioning among preadolescent children with behavior difficulties and their primary caregivers. Participants consisted of 29 caregiver-child dyads as well as each child's classroom teacher. Eligibility for the study was based on the child's placement within a self-contained Emotionally Handicapped (EH) or Severely Emotionally Disturbed (SED) classroom in one of three elementary schools within two west coast Florida counties. Data collection included teacher rating scales pertaining to the severity of each child's behavior and the presence of Callus Unemotional (CU) traits in addition to caregiver and child interviews tapping perceptions of family functioning.

Results …

Risky Predictions, Damn Strange Coincidences, And Theory Appraisal: A Multivariate Corroboration Index For Path Analytic Models, Kristine Y. Hogarty

USF Tampa Graduate Theses and Dissertations

The empirical testing of theories is an important component of research in any field. Yet despite the long history of science, the extent to which theories are supported or contradicted by the results of empirical research remains ill defined. Quite commonly, support or contradiction is based solely on the "reject" or "fail to reject" decisions that result from tests of null hypotheses that are derived from aspects of theory. Decisions and recommendations based on this forced and often artificial dichotomy have been scrutinized in the past.

In recent years, such an overly simplified approach to theory testing has been vigorously …

Mass Transfer Of Ionic Species In Direct And Reverse Osmosis Processes, Silvana Melania Stefania Ghiu

USF Tampa Graduate Theses and Dissertations

This dissertation investigates the importance of diffusional and convective fluxes for salts in reverse osmosis (RO) and nanofiltration (NF) membranes. Moreover, the physical and thermodynamic factors controlling the salt permeability are analyzed. The study utilizes direct osmosis (DO) experiments and RO experiments, the later using both flat sheet and spiral wound membrane configurations. The salts considered are chlorides and acetates of alkali metals and alkaline earth metals.

The equation governing the salt transport in DO experiments is derived and a phenomenon inverse to concentration polarization in RO is observed. The salt permeability in DO is equal to the salt permeability …

Small And Large Signal Modeling Of Mm-Wave Mhemt Devices, William, Clausen

USF Tampa Graduate Theses and Dissertations

This research effort advances millimeter-wave transistor modeling in a current RF/Microwave circuit simulator (Agilent's Advanced Design System-ADS) for small-signal noise and large signal simulations. The device modeled is a metamorphic High Electron Mobility Transistor (mHEMT) supplied by Raytheon RF components. Because of their structure, these new low noise devices are used in this work to test the abilities to accurately model in the sub 0.5dB noise figure territory and to study model prediction into W-band (75-110 GHz).

New modeling issues discussed in this thesis involve the effects of noise modeling in relation to the small-signal model parameters. The noise modeling …

Fpga-Based Implementation Of Concatenative Speech Synthesis Algorithm, Praveen Kumar Bamini

USF Tampa Graduate Theses and Dissertations

The main aim of a text-to-speech synthesis system is to convert ordinary text into an acoustic signal that is indistinguishable from human speech. This thesis presents an architecture to implement a concatenative speech synthesis algorithm targeted to FPGAs. Many current text-to-speech systems are based on the concatenation of acoustic units of recorded speech. Current concatenative speech synthesizers are capable of producing highly intelligible speech. However, the quality of speech often suffers from discontinuities between the acoustic units, due to contextual differences. This is the easiest method to produce synthetic speech. It concatenates prerecorded acoustic elements and forms a continuous speech …

Crystal Engineering Of Binary Compounds Containing Pharmaceutical Molecules, Leslie Ann Morales

USF Tampa Graduate Theses and Dissertations

The synthesis or the interaction between two or more molecules is known as supramolecular chemistry. The concept of supramolecular chemistry can be applied to the design of new pharmaceutical materials affording new compositions of matter with desirable composition, structure and properties.

The design of a two-molecule, or binary, compound using complementary molecules represents an example of an application of crystal engineering. Crystal engineering is the understanding of intermolecular interactions, in the context of crystal packing, in the design of new solid materials. By identifying reliable connectors through molecular recognition or self-assembly, one can build predictable architectures.

The study of supramolecular …

Cvd Growth Of Sic On Novel Si Substrates, Rachael L. Myers

USF Tampa Graduate Theses and Dissertations

Silicon Carbide has been a semiconductor material of interest as a high power and temperature replacement for Silicon (Si) in harsh environments due to the higher thermal conductivity and chemical stability of SiC. The cost, however, to produce this material is quite high. There are also defects in the substrate material (SiC) that penetrate into the active devices layers which are known device killers. Silicon is a material that provides a low cost substrate material for epitaxial growth and does not contain the defects that SiC substrates have. However, the large (~22%) lattice mismatch between Si and SiC creates dislocations …

Bullying And Victimization In Middle School: The Role Of Individual Characteristics, Family Functioning, And School Contexts, Christine Marie Wienke Totura

USF Tampa Graduate Theses and Dissertations

The present study examined the relationship between individual, family, and school variables and both bullying and victimization. Approximately equal numbers of males and females (N = 1185 and 1174, respectively) were randomly selected from classrooms in 11 middle schools across 6th, 7th, and 8th grades. Students completed questionnaires including items from each domain. Questionnaires assessed bullying and victimization, internalizing and externalizing behaviors, family factors, and school variables. In addition, teachers of the selected classrooms completed a brief rating scale on each of the students, which assessed student moodiness, behavioral difficulties, and learning problems. Achievement and discipline records data were obtained. …

Coge1.5Se1.5 : Structural And Transport Properties Characterization, Randolph Ertenberg

USF Tampa Graduate Theses and Dissertations

Skutterudites have been of great interest for thermoelectric applications over the last ten years. Scientific interest has focused on the unique transport properties Skutterudites possess due to the unique crystal structure. Technical interest has grown since it was discovered that some compounds rival the current best thermoelectric materials. To further the understanding of this material system, and optimize its thermoelectric properties, the synthesis and characterization of polycrystalline n- and ptype CoGe1.5Se1.5 was undertaken. Structural, morphological, chemical, electrical, thermal and magnetic properties were studied. These data are compared to those of the binary Skutterudite CoSb3. The results of this study show …

Energy And Transient Power Minimization During Behavioral Synthesis, Saraju P. Mohanty

USF Tampa Graduate Theses and Dissertations

The proliferation of portable systems and mobile computing platforms has increased the need for the design of low power consuming integrated circuits. The increase in chip density and clock frequencies due to technology advances has made low power design a critical issue. Low power design is further driven by several other factors such as thermal considerations and environmental concerns. In low-power design for battery driven portable applications, the reduction of peak power, peak power differential, average power and energy are equally important. In this dissertation, we propose a framework for the reduction of these parameters through datapath scheduling at behavioral …

Vector Flow Model In Video Estimation And Effects Of Network Congestion In Low Bit-Rate Compression Standards, Balaji Ramadoss

USF Tampa Graduate Theses and Dissertations

The use of digitized information is rapidly gaining acceptance in bio-medical applications. Video compression plays an important role in the archiving and transmission of different digital diagnostic modalities. The present scheme of video compression for low bit-rate networks is not suitable for medical video sequences. The instability is the result of block artifacts resulting from the block based DCT coefficient quantization. The possibility of applying deformable motion estimation techniques to make the video compression standard (H.263) more adaptable for bio-medial applications was studied in detail. The study on the network characteristics and the behavior of various congestion control mechanisms was …

Historical Archaeology Of The Indian Key (8mo15) Warehouse: An Analysis Of Nineteenth-Century Ceramics, Lisa Nicole Lamb

USF Tampa Graduate Theses and Dissertations

This thesis describes the archaeological investigation of the Warehouse Complex on Indian Key (8MO15), Monroe County, Florida, through the study of the ceramics recovered from excavations conducted there by the State of Florida from 1972 to 1973 and by the University of South Florida from 1998 to 2002. The Warehouse Complex is composed of two distinct architectural areas, referred to as Feature A and Feature C. This complex lies on the north shore of Indian Key, located in the Atlantic Ocean in the Middle Keys near Islamorada, Florida. The town of Indian Key was founded in the early 1820s, and …

University Copyright Policies For Online Coures: An Evaluative Resource Tool For Unbundling Rights Of Use, Control, And Revenue, Tamara A. Patzer

USF Tampa Graduate Theses and Dissertations

Who cares about who owns online courses? Nobody, because that is not what the issue is really about. Ownership is an emotional issue, but controlling the rights of a copyrightable work is tangible and logical. The important question to answer is not who owns online courses, but who controls the rights of any copyrightable work. For universities and faculty members, getting over the emotional issues and down to the foundation of what is truly at stake is of major concern. While it is nearly impossible to create qualitative guidelines for copyright policies and/or contracts, it is eminently possible to examine …

Gender Differences In Alcohol Expectancies: Influence Of Context And Specificity Of Items, Andrea Hope Weinberger

USF Tampa Graduate Theses and Dissertations

Studies of alcohol expectancies have been equivocal regarding the existence of gender differences. A review of past studies suggested variables that could be useful for future studies such as investigating context-specific expectancies. The current study was designed to investigate the influence of context and item content on gender differences in expectancies. Undergraduate students who reported going to bars once a month or more (N = 321) completed an expectancy measure either while imagining themselves in a bar situation (Context condition) or with no contextual instructions (No Context condition). The expectancy measure consisted of expectancies that were "general" (Social and Tension …

Dry Sliding Tribological Characteristics Of Hard, Flat Materials With Low Surface Roughness, Subrahmanya Mudhivarthi

USF Tampa Graduate Theses and Dissertations

This thesis focuses on identifying hard material pairs with low roughness, high coefficient of static friction, high wear resistance and high modulus of elasticity, suitable for sliding in dry friction conditions under a normal load. A wide range of materials including various steels, various coatings on tool steels deposited by various deposition techniques and different ceramics were examined and considered for tribological testing. Procedures and sequences were developed for conducting tribology tests on the material pairs. High endurance - low cycle tests were conducted and based on the performance of material pairs with respect to friction, wear and surface roughness …

Design And Performance Evaluation Of A New Spatial Reuse Firewire Protocol, Vijay Chandramohan

USF Tampa Graduate Theses and Dissertations

New generations of video surveillance systems are expected to possess a large-scale network of intelligent video cameras with built-in image processing capabilities. These systems need to be tethered for reasons of bandwidth and power requirements. To support economical installation of video cameras and to manage the huge volume of information flow in these networks, there is a need for new shared-medium daisy-chained physical and medium access control (bus arbitration) layer communication protocols.

This thesis describes the design principles of Spatial reuse FireWire Protocol (SFP), a novel request/grant bus arbitration protocol, architected for an acyclic daisy-chained network topology. SFP is a …

Cross-Cultural Measurement Invariance Of Work/Family Conflict Scales Across English-Speaking Samples, David Evan Loran Herst

USF Tampa Graduate Theses and Dissertations

The factor structure of the work/family conflict scale developed by Carlson, Kacmar, & Williams (2000) was analyzed for measurement invariance between a US and an Australian/New Zealand (ANZ) sample using a multisample confirmatory factor analysis procedure. Results indicated that factor pattern fit between the female samples on the common model was good-to-mediocre, and factor pattern fit between the male samples and the common model was mediocre-to-poor. Both samples exhibited significant changes in chi square when testing for the more restrictive factor loading equivalence. Partial measurement invariance revealed a better fit between the male samples when three of the items were …

Graph-Theoretic Techniques For Web Content Mining, Adam Schenker

USF Tampa Graduate Theses and Dissertations

In this dissertation we introduce several novel techniques for performing data mining on web documents which utilize graph representations of document content. Graphs are more robust than typical vector representations as they can model structural information that is usually lost when converting the original web document content to a vector representation. For example, we can capture information such as the location, order and proximity of term occurrence, which is discarded under the standard document vector representation models. Many machine learning methods rely on distance computations, centroid calculations, and other numerical techniques. Thus many of these methods have not been applied …

Characterization And Modeling Of Planar Spiral Inductors And Pad Stack Parasitic Effects, John Capwell

USF Tampa Graduate Theses and Dissertations

This thesis concentrates on RF/microwave characterization and modeling of planar spiral inductors and pad stack parasitics. The inductors varied in size from 1.9 to 15.3 nH. Several approaches were examined for modeling the planar spiral inductors. The approach developed herein is built around an existing composite model (available in commercial computer-aided design software), with added series and shunt impedances at both the input and output of the existing composite model. Artificial neural network (ANN) software was used to determine the correction impedance values. Another approach investigated was to model the S-parameters of the inductor using a space- mapping model of …

Semiparametric Estimation Of Unimodal Distributions, Jason K. Looper

USF Tampa Graduate Theses and Dissertations

One often wishes to understand the probability distribution of stochastic data from experiment or computer simulations. However, where no model is given, practitioners must resort to parametric or non-parametric methods in order to gain information about the underlying distribution. Others have used initially a nonparametric estimator in order to understand the underlying shape of a set of data, and then later returned with a parametric method to locate the peaks. However they are interested in estimating spectra, which may have multiple peaks, where in this work we are interested in approximating the peak position of a single-peak probability distribution.

One …

A Reinforcement Learning Approach To Obtain Treatment Strategies In Sequential Medical Decision Problems, Radhika Poolla

USF Tampa Graduate Theses and Dissertations

Medical decision problems are extremely complex owing to their dynamic nature, large number of variable factors, and the associated uncertainty. Decision support technology entered the medical field long after other areas such as the airline industry and the manufacturing industry. Yet, it is rapidly becoming an indispensable tool in medical decision making problems including the class of sequential decision problems. In these problems, physicians decide on a treatment plan that optimizes a benefit measure such as the treatment cost, and the quality of life of the patient. The last decade saw the emergence of many decision support applications in medicine. …

Organizational Office Space In The Virtual Age: The Role Of Shared Space In Communication, Sheila Gobes-Ryan

USF Tampa Graduate Theses and Dissertations

This thesis takes a phenomenological approach to the examination of the organizational need for shared office space. Questions are developed in a reflexive narrative that introduces challenges to the assumption that space is a given in organizations. The narrative also uses the process of questioning this basis assumption to develop a new understanding of the role of space in organizations in supporting the development of common language needed for the creation of organizational knowledge. Key ideas from systems theory, autopoiesis, organizational theory, semiotics, and psychology are utilized as resources developing the ideas.

A Molecular Approach To Assessing Meiofauna Diversity In Marine Sediments, Heather C. Hamilton

USF Tampa Graduate Theses and Dissertations

A Molecular Approach to Assessing Meiofauna Diversity in Marine Sediments Heather C. Hamilton Abstract The purpose of this study was to determine if a molecular approach could be applied to calculating the diversity of meiofauna in marine sediments from two sites in Tampa Bay, FL, similar to the approach of McCaig et al, 1999 in calculating the diversity of microbes in pastureland soils. The approach includes extracting total DNA directly from the sediment and amplifying the 18S rRNA gene by PCR. Clone libraries from the 18S gene would be created for each site and 300 sequences from each clone library …

Falun Gong In The United States: An Ethnographic Study, Noah Porter

USF Tampa Graduate Theses and Dissertations

Falun Gong, also known as Falun Dafa, has been described in many ways. It has been called qigong, one of many schools of physical exercises that aim at improving health and developing "supernatural abilities". Scholars and mainstream media have referred it to as a "spiritual movement" or religion, although practitioners claim it is not a religion. It has been called a cult, in the pejorative sense rather than in a sociological context, by the Chinese government and by some Western critics. In the writings of Li Hongzhi, the founder of Falun Gong, it is referred to in different ways, …

Use Of Silica-Supported Adsorbents, Modified Silica Gel, Modified Montmorillonite Ksf And Magnetite In The Remediation Of Selected Heavy Metals From Aqueous Media, Craig Alcindor Ivan Bowe

USF Tampa Graduate Theses and Dissertations

Pollution of the earth's water resources, including freshwater sources such as lakes and rivers, by heavy metals have been a detriment to the environment for as long as the industrial age of man. As these metallic pollutants accumulate in the supply of precious groundwater and drinking water the need for clean-up technologies to combat the increasing threat is becoming of more importance to government and industry alike. Previous work has established the possibility of using known chelating agents, such as LIX-54® supported on silica gel in the removal of selected heavy metal ions such as copper(II), nickel(II) , and cadmium(II) …

A Qualitative Exploration Of Reflective Thinking In Experiential Learning Debriefings, Lynn D. Grinnell

USF Tampa Graduate Theses and Dissertations

The purpose of this study was to explore the nature of cognitive and emotional processes during the three reflective stages of the experiential learning cycle of experiential activities using written debriefings. The study examined three written debriefings from five senior-level undergraduate management students enrolled in a business management course. The debriefings consisted of four to five free-response questions modeled after Kolb’s experiential learning cycle: concrete experience, reflective observation, abstract conceptualization, and active experimentation. The study triangulated results using two qualitative methods, a grounded theory analysis and a content analysis. In the grounded theory analysis, two process maps were developed from …

Embedded Cryptography: An Analysis And Evaluation Of Performance And Code Optimization Techniques For Encryption And Decryption In Embedded Systems, Jayavardhan R. Kandi

USF Tampa Graduate Theses and Dissertations

It is clear that Cryptography is computationally intensive. It is also known that embedded systems have slow clock rates and less memory. The idea for this thesis was to study the possibilities for analysis of cryptography on embedded systems. The basic approach was the implementation of cryptographic algorithms on high-end, state-of-the-art, DSP chips in order to study the various parameters that optimize the performance of the chip while keeping the overhead of encryption and decryption to a minimum.

Embedded systems are very resource sensitive. An embedded system is composed of different components, which are implemented in both hardware and software. …