Digital Commons Network^™

Sorption Of Organic Vapors By Copolymers Of Poly (Styrene-Butadiene) Using A Piezoelectric Microbalance, Anant K. Upadhyayula

USF Tampa Graduate Theses and Dissertations

Thickness shear mode (TSM) sensors, also known as quartz crystal microbalances (QCM) are a class of acoustic wave sensors that have been used for gas phase sensing. In this thesis this device is used to measure vapor-liquid equilibrium data for copolymers of poly(styrene-butadiene) at 294K.

Copolymers of poly(styrene-butadiene) with varying percentages of styrene (85%, 45% and 21 %) were studied with benzene, n-hexane, dichloroethane and chloroform as solvents. Literature data for pure polystyrene/benzene and polystyrene/chloroform and polybutadiene/benzene were obtained to complement the measured data.

Obtained experimental data were fit with a modified Flory-Huggins model and compared with the predictions of …

Three Studies Of Problem Solving In Collaborative Software Development, Madeline Ann Domino

USF Tampa Graduate Theses and Dissertations

A potential solution to producing quality software in an acceptable time frame may be found by using the newer, innovative methods, such as collaborative software development. The purpose of this dissertation is to examine the individual developer characteristics, developmental settings, collaborative methods and the processes during development that impact collaborative programming performance and satisfaction outcomes.

Understanding individual differences in performance in the collaborative development setting is important, since it may help us understand how the collaborative setting may raise the lowest level of performance to much higher levels, as well as how to select individuals for collaborative development. Exploring the …

Integrated Uv-Vis Multiangle-Multiwavelength Spectrometer For Characterization Of Micron And Sub-Micron Size Particles, Yong-Rae Kim

USF Tampa Graduate Theses and Dissertations

Characterization of micron and sub-micron size particles requires the simultaneous measurement of the joint particle property distribution (JPPD). The JPPD is comprised of particle size, shape, orientation, composition, optical properties, and surface properties. Measurement of each of the particle properties independently is a difficult task and it has been only partially successful. To determine as many particle properties as possible using optical methods it is necessary to simultaneously measure all aspects of the interaction of the incident light with the particles of interest. This approach leads to the concept of multidimensional spectroscopy suggested by Prof. Garcia-Rubio. Dr. Bacon proved the …

The Construct Validation Of An Instrument Based On Students’ University Choice And Their Perceptions Of Professor Effectiveness And Academic Reputation At The University Of Los Andes, Josefa Maria Montilla

USF Tampa Graduate Theses and Dissertations

The purpose of this study was to examine the construct validation of an instrument based on students university choice and their perceptions of professor effectiveness and academic reputation at the University of Los Andes (ULA). Moreover, a comparative analysis was carried out to determine how the selected factors that influence the students decisions and perceptions differ according to student demographic factors such as: gender and university campus.

This instrument was developed with items based on the three domains formulated: university choice process, professor effectiveness, and university academic reputation. To determine the instruments appropriateness to measure the students decisions in university …

Multi-Event Crisis Management Using Non-Cooperative Repeated Games, Upavan Gupta

USF Tampa Graduate Theses and Dissertations

The optimal allocation of the resources to the emergency locations in the event of multiple crises in an urban environment is an intricate problem, especially when the available resources are limited. In such a scenario, it is important to allocate emergency response units in a fair manner based on the criticality of the crisis events and their requests. In this research, a crisis management tool is developed which incorporates a resource allocation algorithm. The problem is formulated as a game theoretic framework in which the crisis events are modeled as the players, the emergency response centers as the resource locations …

Development Of A Generic Pda Based Control Mechanism For In-House Fabricated Miniature Sensors, Sunny Kedia

USF Tampa Graduate Theses and Dissertations

A novel method of controlling miniature sensors using Handspring Visor Prism PDA has been implemented. A generic motherboard was developed to map the data and address lines from the Visor onto a Complex Programmable Logic Device (CPLD) to provide basic electrical signals to the sensor board. The sensor board housed the sensor and contained application specific circuitry. The PDA, the motherboard, and the sensor board completed the control mechanism for the sensor. Miniature sensors and PDA based control mechanism scaled down the size of the complete system making the unit portable. This unit facilitated a faster analysis of data on …

Characteristics Of A Chronically, Rapidly Eroding Beach: Long Key, Pinellas County, Florida, Alyssa L. Saint John

USF Tampa Graduate Theses and Dissertations

Long Key, on the central western coast of Florida, has been nourished repeatedly since 1975. Following nourishment, the beach has rapidly eroded. This study documents rates, processes, and mechanisms for the rapid erosion. To better understand the beach performance, it is crucial to quantify the background erosion rate when artificial beach fill is at its minimum. This year long study from February 2003 through March of 2004 provides a detailed examination of the performance of a natural beach experiencing intense erosion.

The primary objective is to analyze the performance of Long Key through detailed investigation of shoreline and beach-volume changes …

Morphodynamics Of Bunces Pass, Florida, Jack C. Wilhoit Ii

USF Tampa Graduate Theses and Dissertations

Bunces Pass is an unstructured tide-dominated inlet just north of the main entrance to Tampa Bay, Florida. The inlet has been stable for at least 130 years, as the size, shape, and orientation have remained unchanged. The morphological evolution of the Bunces Pass ebb-tidal delta is influenced by adjacent inlets. Historically, the ebb tidal delta was extremely large, due to the presence of the south channel of Pass-A-Grille Pass. As the tidal prism decreased through the south channel, the sheltering effect produced by the large ebb tidal delta diminished, and large volumes of sand began migrating shoreward. Sediment from the …

Road Crack Condition Performance Modeling Using Recurrent Markov Chains And Artificial Neural Networks, Jidong Yang

USF Tampa Graduate Theses and Dissertations

Timely identification of undesirable pavement crack conditions has been a major task in pavement management. Up to date, myriads of pavement performance models have been developed for forecasting pavement crack condition with the traditional preferred techniques being the use of regression relationships developed from laboratory and/or field statistical data. However, it becomes difficult for regression techniques to predict the crack performance accurately and robustly in the presence of a variety of tributary factors, high nonlinearity, and uncertainty. With the advancement of modeling techniques, two innovative breeds of models, Artificial Neural Networks and Markov Chains, have drawn increasing attention from researchers …

Antenna Array Output Power Minimization Using Steepest Descent Adaptive Algorithm, Sandra Gomulka Johnson

USF Tampa Graduate Theses and Dissertations

A beamforming antenna array is a set of antennas whose outputs are weighted by complex values and combined to form the array output. The effect of the complex valued weights is to steer lobes and nulls of the array pattern to desired directions. These directions may be unknown and so the antenna weights must be adjusted adaptively until some measure of array performance is improved, indicating proper lobe or null placement.

An adaptive algorithm to adjust the complex weights of an antenna array is presented that nulls high power signals while allowing reception of GPS signals as long as the …

Caffeine And Airway Resistance, Gwyn N. Crump M.D.

USF Tampa Graduate Theses and Dissertations

This study investigated the effect of caffeine on airway resistance. The subjects were drawn from volunteers (18-90 years old) in good health, with no major cardiopulmonary conditions.

We found no association between the consumption of a single cup of the caffeinated beverage coffee and a decrease in airway resistance within one hour in a normal sample of subjects as measured by impulse oscillometry nor with conventional spirometry . It appears that any possible bronchodilatory effect of the caffeine from a single cup of coffee in a normal population is below the limit of detection of spirometry and impulse oscillometry or …

Efforts To Promote Tourism As A Catalyst For Urban Redevelopment In Florida: Insights From The Anthropology Of Tourism And An Annotated Bibliography., John F. Collins

USF Tampa Graduate Theses and Dissertations

Tourism is a major contributor to the global economy and is an agent of cultural change. Tourism has been utilized throughout the United States as an engine of economic renewal in the promotion of redevelopment within many of our most celebrated urban centers. Urban tourism as it is found within Florida is explored. A chapter is dedicated to Tampa, Florida. Anthropology has spent little time or effort in attempting to understand the complexities of urban tourism and what it means for the cities of 21st century. The anthropology of tourism is utilized in exploring the political economy of tourism within …

High Voltage Conversion For Mems Applications Using Micromachined Capacitors, Puneet Khanna

USF Tampa Graduate Theses and Dissertations

This thesis explores high voltage converter circuits for MEMS applications using micromachined devices. A novel MEMS based tunable DC-DC converter has been developed. Conventional high voltage converters based on charge pumps are unable to convert voltages to higher than few tens of volts due to power handling limitations of the CMOS components. In order to overcome this limitation a high voltage circuit has been proposed, which when integrated with micromachined switches will generate output voltages in the range of 100 Volts. The converter is based on a two phase switched capacitor circuit, and allows regulation of voltage conversion ratio. Three …

Studies On Modeling Angular Soil Particles Using The Discrete Element Method, Amr M. Sallam

USF Tampa Graduate Theses and Dissertations

The Discrete Element Method was first introduced by Cundall and Strack (1979) to model granular soils within the context of geotechnical engineering. The material is modeled as a random assembly of discrete elements. Each particle interacts with neighboring particles through contact forces that can be built up and broken at any time. The particles were modeled as discs in 2-D or as spheres in 3-D. Research studies have been conducted to improve the simulation of actual grain shapes. Ashmawy et al. (2003) developed the overlapping rigid clusters (ORC) method to accurately model irregular particle shapes. The idea relies on clumping …

Chemical And Photolytic Degradation Of Polyacrylamides Used In Potable Water Treatment, Peiyao Cheng

USF Tampa Graduate Theses and Dissertations

Polyacrylamides (PAMs) are a class of polymers formed from acrylamide alone or copolymerized with other monomers. PAMs have been used in drinking water treatment as flocculants or coagulants in the highest volume among all the polymer types. In potable water treatment processes, polyacrylamides are often exposed to oxidants (e.g. chlorine and permanganate) and UV irradiation from sunlight or artificial sources. The purpose of this study is to evaluate the possible degradation of PAMs caused by chemical oxidation and/or UV irradiation.

Three types of PAM products (nonionic, cationic and anionic) were studied under free chlorine and permanganate oxidation, UV irradiation, and …

Mineral Solubilization From Municipal Solid Waste Combustion Residues: Implications For Landfill Leachate Collection Systems, Lisa R. Rhea

USF Tampa Graduate Theses and Dissertations

Leachate collection systems consist of a series of pipes installed beneath the waste at the base of a landfill. The liquid drains toward a central location where it is pumped and then treated, discharged, or recirculated. In some landfills, solid precipitates form in the collection system resulting in clogging and malfunctions of the drainage system. The formation of the precipitates is linked to the chemical and biological stability of the leachate generated within the landfill. To control the formation of precipitates and prevent clogging of leachate collection systems, it is important to understand factors that influence leachate characteristics.

Ashes from …

Modeling Alternate Strategies For Airline Revenue Management, Kapil Joshi

USF Tampa Graduate Theses and Dissertations

Ever since the deregulation of the airline industry in 1978, fierce competition has made every airline try and gain a competitive edge in the market. In order to accomplish this, airlines are turning to advanced optimization techniques such as revenue management. Revenue management is a way for airlines to maximize capacity and profitability by managing supply and demand through price management.

Over the last few years research in the field of revenue management has steadily progressed from seat inventory control techniques such as single leg seat inventory and network inventory control to ticket pricing techniques. Ticket pricing techniques involve setting …

Gait-Based Recognition At A Distance: Performance, Covariate Impact And Solutions, Zongyi Liu

USF Tampa Graduate Theses and Dissertations

It has been noticed for a long time that humans can identify others based on their biological movement from a distance. However, it is only recently that computer vision based gait biometrics has received much attention. In this dissertation, we perform a thorough study of gait recognition from a computer vision perspective. We first present a parameterless baseline recognition algorithm, which bases similarity on spatio-temporal correlation that emphasizes gait dynamics as well as gait shapes. Our experiments are performed with three popular gait databases: the USF/NIST HumanID Gait Challenge outdoor database with 122 subjects, the UMD outdoor database with 55 …

Lake Stage Fluctuation Study In West-Central Florida Using Multiple Regression Models, Jie Gao

USF Tampa Graduate Theses and Dissertations

Multiple linear regression models were developed to calculate lake fluctuation that occurs between 10 percent, 50 percent, and 90 percent of the time lake surface elevation is exceeded. A total of 48 lakes were selected from Hillsborough, Pasco, Highlands and Polk counties, which were identified as natural lakes through the study the Southwest Florida Water Management District (SWFWMD) conducted in 1999 and 2002 to develop the models. "Natural lake" refers to lakes that were not impacted by ground water pumping.

Among these 48 lakes, 22 lakes from Hillsborough and Pasco counties sit in the coastal lowlands area. 26 lakes from …

Performance Evaluation Of Multi-Product Kanban-Like Control Systems, Sachin S. Deokar

USF Tampa Graduate Theses and Dissertations

Over the years, much attention has been given to the analysis of the pull type ordering system to reduce in-process inventory and to improve product quality. Kanban Control Systems are widely used to control the release of parts in multi-stage manufacturing systems operating under a pull mechanism. Considerable research has been done to study the individual manufacturing systems for multi stage and single product. However, not much research has been done to compare different pull control policies for multi product manufacturing systems.

Most of the research done in multi-product system assumes that a kanban card is dedicated to a part …

Low Power Technology Mapping And Performance Driven Placement For Field Programmable Gate Arrays, Hao, Li

USF Tampa Graduate Theses and Dissertations

As technology geometries have shrunk to the deep sub-micron (DSM) region, the chip density and clock frequency of FPGAs have increased significantly. This makes computer-aided design (CAD) for FPGAs very important and challenging. Due to the increasing demands of portable devices and mobile computing, low power design is crucial in CAD nowadays. In this dissertation, we present a framework to optimize power consumption for technology mapping onto FPGAs. We propose a low-power technology mapping scheme which is able to predict the impact of choosing a subnetwork covering on the ultimate mapping solution. We dynamically update the power estimation for a …

An Event Driven Single Game Solution For Resource Allocation In A Multi-Crisis Environment, Rashmi S. Shetty

USF Tampa Graduate Theses and Dissertations

The problem of resource allocation and management in the context of multiple crises occurring in an urban environment is challenging. In this thesis, the problem is formulated using game theory and a solution is developed based on the Nash equilibrium to optimize the allocation of resources to the different crisis events in a fair manner considering several constraints such as the availability of resources, the criticality of the events, the amount of resources requested etc. The proposed approach is targeted at managing small to medium level crisis events occurring simultaneously within a specific pre-defined perimeter with the resource allocation centers …

Modelling Distance Functions Induced By Face Recognition Algorithms, Soumee Chaudhari

USF Tampa Graduate Theses and Dissertations

Face recognition algorithms has in the past few years become a very active area of research in the fields of computer vision, image processing, and cognitive psychology. This has spawned various algorithms of different complexities. The concept of principal component analysis(PCA) is a popular mode of face recognition algorithm and has often been used to benchmark other face recognition algorithms for identification and verification scenarios. However in this thesis, we try to analyze different face recognition algorithms at a deeper level. The objective is to model the distances output by any face recognition algorithm as a function of the input …

Bayesian Inference In Forecasting Volcanic Hazards: An Example From Armenia, Jennifer N. Weller

USF Tampa Graduate Theses and Dissertations

Scientists worldwide are increasingly faced with the need to assess geologic hazards for very infrequent events that have high consequence, for instance, in siting nuclear facilities for volcanic hazards. One of the methods currently being developed for such assessments is the Bayesian method. This paper outlines the Bayesian technique by focusing on the volcanic hazard assessment for the Armenia Nuclear Power Plant, (ANPP), which is located in a Quaternary volcanic field. The Bayesian method presented in this paper relies on the development of a probabilistic model based on the spatial distribution of past volcanic events and a geologic process model. …

Efficient And Effective? The Hundred Year Flood In The Communication And Perception Of Flood Risk, Heather Bell

USF Tampa Graduate Theses and Dissertations

In response to the rising costs of floods, the United States has adopted sophisticated programs to mitigate the loss of life and property. However, the efficient implementation of certain aspects of flood policy has taken precedence over effective communication. The scope of the National Flood Insurance Program and the efficient coding of "the 100 year flood" have led to a pervasive use of the term in both formal and informal risk communication. When officials began consciously communicating flood policy to the public, they assumed a narrow "engineering" model and did not fully anticipate the influence of informal communication on the …

A Sensitivity Analysis Of A Heuristic Model Used For The Placement Allocation Of Utilities In Transportation Right-Of-Way Corridors, Steve Clarence Christian

USF Tampa Graduate Theses and Dissertations

The requirements for public utility systems in the United States of America have grown enormously over the years triggering a tremendous shortage for space available to public utilities on and within transportation right-of-ways (ROW). Overcrowding and improper location of utilities has resulted in problems such as, damage to infrastructure, traffic accidents and, interruption of service to customers. The project titled, "Optimal Placement of Utilities within FDOT Right-of-Way", sponsored by the Florida Department of Transportation (FDOT), and currently being investigated at the University of South Florida, presents a decision-making heuristic aimed at developing a better utility placement allocation system (Kranc et. …

Numerical Simulation Of Thermal Comfort And Contaminant Transport In Air Conditioned Rooms, Son Hong Ho

USF Tampa Graduate Theses and Dissertations

Health care facilities, offices, as well as workshops and other commercial occupancies, require ventilation and air conditioning for thermal comfort and removal of contaminants and other pollutions. A good design of ventilation and air conditioning provides a healthy and comfortable environment for patients, workers, and visitors.

The increasing developments of computational fluid dynamics (CFD) in the recent years have opened the possibilities of low-cost yet effective method for improving HVAC systems in design phase, with less experiment required. This work presents numerical simulations of thermal comfort and contaminant removal for two typical working spaces where these factors are critical: a …

Analysis Of Flow In A 3d Chamber And A 2d Spray Nozzle To Approximate The Exiting Jet Free Surface, Chin Tung Hong

USF Tampa Graduate Theses and Dissertations

The purpose of this investigation is to analyze the flow pattern of cooling fluids in the 3D "twister-effect" mixing chamber and to approximate the free surface behaviors exiting the 2D spray nozzle. The cone angle and free surface height located at the end of the free surface are two significant factors to determine the spraying area on a heated plane. This process is a reasonable representation of many industrial cooling application. The whole system consists of 4 inlet tubes connected to the top of the mixing chamber, and the spray nozzle is located under the chamber. Four different refrigerants, like …

Modeling Of Qe, I-V Characteristics Of Msm (Metal-Semiconductor-Metal) Mercuric Iodide Thin Films With MediciTm, Vikram Rupavatharam

USF Tampa Graduate Theses and Dissertations

Mercuric Iodide is the most promising of all semiconductor materials currently under investigation for use as radiation detectors at room temperature. While substantial studies have been conducted on single crystal HgI₂, polycrystalline HgI₂ remains a comparatively less studied form.

The HgI₂ films are deposited on TEC-15 LOF glass with a Tin Oxide (SnO₂) coating which acts as the growth surface and front contact. The back contact, Palladium (Pd), is deposited by sputtering through a shadow mask. The films are circular in shape with an approximate diameter of 2.5 cm and thicknesses ranging from 50-600 …

Slurry Sand Content And Concrete Interaction In Drilled Shaft Construction, Gregory Gene Deese

USF Tampa Graduate Theses and Dissertations

Due to the widespread use of drilled shafts in state and federal highway bridges, strict regulation of the design and construction has been imposed by the respective agencies. However, documented cases of anomalies and/or poorly performing shafts continue to arise. To this end, this thesis investigates several aspects of drilled shaft construction that may affect the quality of the finished product. These areas include bentonite slurry properties and performance as well as reinforcement cage and concrete flow interactions.

Recent research indicates tremie poured concrete does not flow as predicted. Instead of even rising, a differential between the height of concrete …