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Design And Development Of A Silicon Carbide Chemical Vapor Deposition Reactor, Matthew T. Smith

USF Tampa Graduate Theses and Dissertations

The goal of this thesis is to present the design and development of a chemical vapor deposition reactor for the growth of high quality homoepitaxy silicon carbide films for electronic device applications. The work was performed in the Nanomaterials and Nanomanufacturing Research Center at the University of South Florida from 8/2001-5/2003.

Chemical vapor deposition (CVD) is the technique of choice for SiC epitaxial growth. Epitaxial layers are the building blocks for use in various semiconductor device applications. This thesis reports on a SiC epitaxy process where a carrier gas (hydrogen) is saturated with reactive precursors (silane and propane) which are …

Optimizing Cost And Data Entry For Assignment Of Patients To Clinical Trials Using Analytical And Probabilistic Web-Based Agents, Bhavesh Dineshbhai Goswami

USF Tampa Graduate Theses and Dissertations

A clinical trial is defined as a study conducted on a group of patients to determine the effect of a treatment. Assignment of patients to clinical trials is a data and labor intensive task. Usually, medical personnel manually check the eligibility of a patient for a clinical trial based on the patient's medical history and current medical condition. According to studies, most clinical trials are under-enrolled which negatively affects their effectiveness. We have developed web-based agents that can test the eligibility of patients for many clinical trials at once. We have tested various heuristics for optimizing cost and data entry …

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 …

Evaluation Of Pile Driving Lead Section, Kadir Uslu

USF Tampa Graduate Theses and Dissertations

Driving piles constitute a large portion of the high-capacity foundations used today. They transfer structural loads to deep bearing strata when adequate surficial soils are not available. The mechanisms required to install these piles generally consist of a hammer, hammer lead, a crane, and various support rigging.

This study focused on lead sections, specifically, one which was manufactured by Berminghammer Foundation Equipment, Inc. The dimensions and strength of a lead section must be capable of supporting both the pile driving hammer and the longest anticipated pile for a given site. The strength of the section must be capable of withstanding …

Genetic Changes In Natural Populations Caused By The Release Of Cultured Fishes, Michael Dominic Tringali

USF Tampa Graduate Theses and Dissertations

Genetic changes likely occur in wild fish populations as a consequence of interactions with cultured fish, but to what extent do those changes threaten the maintenance of natural genetic diversity and population viability? Following a review and categorization of numerous processes suspected of being agents of post-release genetic change in recipient wild populations (Chapter 1), I focus on risks relating to the magnitude and duration of releases -- but with a twist. That is, I assume that the mean fitness of released, cultured individuals does not differ from that of the recipient natural population. Throughout, attention is devoted to potential …

Monaural Speech-In-Noise Thresholds Using The Hearing In Noise Test (Hint), Denise Parrish

USF Tampa Graduate Theses and Dissertations

Understanding speech in background noise is occasionally difficult for normal hearing listeners and is often impossible for the listener with sensorineural hearing loss. The ability to understand speech in noise depends upon multiple factors such as the characteristics of the speech signal, the signal-to-noise ratio, and the listener's degree of hearing impairment. A routine hearing evaluation usually does not provide ample information about a listener's functional communication abilities. The Hearing-in-Noise Test (HINT) developed by The House Ear Institute provides an efficient and reliable method for evaluating an individual's suprathreshold speech understanding ability in quiet and in noise.

The purpose of …

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 …

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 …

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 …

Effect Sizes, Significance Tests, And Confidence Intervals: Assessing The Influence And Impact Of Research Reporting Protocol And Practice, Melinda Rae Hess

USF Tampa Graduate Theses and Dissertations

This study addresses research reporting practices and protocols by bridging the gap from the theoretical and conceptual debates typically found in the literature with more realistic applications using data from published research. Specifically, the practice of using findings of statistical analysis as the primary, and often only, basis for results and conclusions of research is investigated through computing effect size and confidence intervals and considering how their use might impact the strength of inferences and conclusions reported.

Using a sample of published manuscripts from three peer-rviewed journals, central quantitative findings were expressed as dichotomous hypothesis test results, point estimates of …

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 …

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. …

Congruence Among Mathematics Skills Used On The Job By Practical Nurses Vs. The Prerequisite Skills Required For Admission Into The Practical Nursing Program, G H. Clary

USF Tampa Graduate Theses and Dissertations

The standard for evaluating a student's mathematic ability (grade level) for admission to many vocational-technical programs is through the administration of the Tests of Adult Basic Education (TABE). There has come forth a concern from vocational educators, that students entering programs may not be prepared for the mathematics required by the curriculum, even though the student has met the criteria for entry as established by the state curriculum frameworks as evidenced by their scores on a TABE which had recently been administered. Furthermore, questions raised among instructional, administrative and guidance personnel about the congruence of math skills required on the …

The Effects Of Citizenship Performance, Task Performance, And Rating Format On Performance Judgments, David R. Coole

USF Tampa Graduate Theses and Dissertations

The current study examined the effects of citizenship performance, task performance, and rating format on overall and task performance ratings. Levels of citizenship performance (high, medium, low), task performance (high, medium, low), and rating format (inclusion or exclusion of citizenship performance) were experimentally manipulated in a 3x3x2 between-subjects full factorial design. Ratings were provided by 360 undergraduate psychology students evaluating experimentally developed supervisory logs of first line financial managers. Targets' levels of citizenship and task performance were positively related to raters' judgments of overall and task performance. The prediction that this relationship would be moderated by task performance level was …

Signs Of Life: Rediscovering Nineteenth Century Indian Key Through Glass Analysis, Alexis Broadbent Sykes

USF Tampa Graduate Theses and Dissertations

Archaeological investigations of Indian Key Historic State Park in the Florida Keys have uncovered a wide range of historical artifacts from throughout the nineteenth century that reveal how the site was reused and reoccupied through time. This thesis focuses on the glass component recovered from a house cistern complex (Feature F) and a warehouse (Features A and C) during the 1998 to 2002 field seasons. Glass artifacts range from a variety of bottle glass including alcohol bottles and proprietary medicines, to cut glass such as tumblers and decanters, to window glass.

Feature F's analysis has shown that it maintained a …

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 …

Implementation Of An Acoustic Echo Canceller Using Matlab, Srinivasaprasath Raghavendran

USF Tampa Graduate Theses and Dissertations

The rapid growth of technology in recent decades has changed the whole dimension of communications. Today people are more interested in hands-free communication. In such a situation, the use a regular loudspeaker and a high-gain microphone, in place of a telephone receiver, might seem more appropriate. This would allow more than one person to participate in a conversation at the same time such as a teleconference environment. Another advantage is that it would allow the person to have both hands free and to move freely in the room. However, the presence of a large acoustic coupling between the loudspeaker and …

Diversity And Production Of Phytoplankton In The Offshore Mississippi River Plume And Coastal Environments, Boris Wawrik

USF Tampa Graduate Theses and Dissertations

River discharge leads to extensive phytoplankton blooms often observed in ocean color satellite images to extend far into the open ocean as high chlorophyll plumes. We investigated diversity, distribution and ecology of phytoplankton populations in the Mississippi River plume, both spatially and in the water column using molecular tools. A method was developed for the quantification of diatom/pelagophyte rbcL (large subunit of Ribulose-1,5-bisphosphate Carboxylase/Oxygenase) mRNA using quantitative PCR and applied to cultures and in the plume. The vertical structure of phytoplankton species in the Mississippi River plume was described by flow cytometry, pigments, rbcL mRNA and rbcL cDNA libraries. High …

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 …

The Bases Of Opposition To Affirmative Action: An Attitude Change Effort, Meisha-Ann Martin

USF Tampa Graduate Theses and Dissertations

The present study examined the effects of perceptions of fairness, prejudice and collective self-interest on the affirmative action attitudes of 85 White undergraduate students. Participants were classified as non-racists, modern racists or old-fashioned racists based on their scores on the Implicit Association Test and Attitudes Toward Blacks scale. In the first phase of the study, participants read affirmative action information preceded by either high or low attention instructions. In the second phase, fairness, status of position and race of the target of an affirmative action plan were manipulated using vignettes. No significant differences were found in the first phase of …

Your Computer Is Watching You: Intelligent Agents And Social Facilitation, Jason R. Read

USF Tampa Graduate Theses and Dissertations

This study investigates whether the social facilitation effect takes place when a person performs a computerized task that includes an animated intelligent agent (IA). The moderating effects of two individual differences, locus of control (LOC) and microcomputer playfulness (MCP), are tested for. It was proposed that an IA's presence would cause participants to exhibit this effect and that LOC and MCP would moderate a participant's arousal, measured as state anxiety, such that those possessing an internal LOC and those exhibiting high MCP would experience less arousal when performing computerized tasks with an IA present. Data was analyzed using a 2 …

Packet Loss Concealment In Voice Over Internet, Rishikesh S. Gokhale

USF Tampa Graduate Theses and Dissertations

Traditional telephony networks with their cumbersome and costly infrastructures are being replaced with voice being transmitted over the Internet. The Internet is a very commonly used technology that was traditionally used to transmit data. With the availability of large bandwidth and high data rates the transmission of data, voice and video over the Internet is gaining popularity. Voice is a real time application and the biggest problem it faces is the loss of packets due to network congestion. The Internet implements protocols to detect and retransmit the lost packets. However, for a real time application it is too late before …

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, …

Relative Motion History Of The Pacific-Nazca (Farallon) Plates Since 30 Million Years Ago, Douglas T. Wilder

USF Tampa Graduate Theses and Dissertations

Relative plate motion history since 30 Ma between the Pacific and the southern portion of the Nazca (Farallon) plates is examined. The history is constrained by available seafloor magnetic anomaly data and a two-minute grid of predicted bathymetry derived from satellite altimetry and shipboard sensors. These data are used to create a new plate motion reconstruction based on new magnetic anomaly identifications and finite poles of motion. The new identified magnetic isochrons and tectonic reconstruction provides greater resolution to the tectonic history between chrons 7y (24.73 Ma) and 3 (4.18 Ma) than previous interpretations.

Shipboard magnetics and aeromagnetic data from …

Serial Murder In Institutional Settings, Jennifer D. Grine

USF Tampa Graduate Theses and Dissertations

This research explored the topic of professional caregivers who commit serial murder in institutional settings. In-depth case studies were created for individuals convicted of serial murder in institutional settings in the United States. The purpose of this research was to identify the characteristics of this group of institutional serialists and compare the current data to existing data on serial killers. A technique of secondary data analysis was utilized to gather information on the sample of 17 individuals. Only public information was reviewed. Results of the data comparison between the current sample and existing information on serial killers indicated that institutional …