Digital Commons Network^™

A Viewpoint Of Tanzania E-Commerce And Implementation Barriers, George S. Oreku, Fredrick Mtenzi, Al-Dahoud Ali

Articles

The growing rate of ICT utilization particularly the Internet and mobile phones has influenced at an exponential rate online interaction and communication among the generality of the populace. However, with the enormity of businesses on the Internet, Tanzania is yet to harness the opportunities for optimal financial gains. This study is exploratory in nature as it attempts to unveil the prospects of ecommerce implementation, participation, motivation and opportunity to the developing countries like Tanzania where by the domestic market is very big to ensure the growth of agricultural sector. The paper proposes to investigate the ability of consumers to purchase …

Analysis Of Model Uncertainty In Hydraulic Modeling: The Bstem Application To The Osage River, Annabell Leigh Ulary

Masters Theses

"Uncertainty is inevitable when creating any kind of model. A model can be used in the most accurate way possible, if the uncertainties are understood. This study determines the level of uncertainty in the Bank Stability and Toe Erosion Model (BSTEM) of the Osage River downstream of Bagnell Dam between Lake Ozark, MO and Jefferson City, MO. The statistical analysis of the BSTEM model was performed using the aid of SAS statistical computer modeling software. There were 4 different analysis values used to determine the best fit model for all dependent variables. These values include the F-test, the coefficient of …

Comparison Of Class Ii Injection Well Area Of Review Requirements With Area Of Evaluation For Hydraulically Fractured Wells, Yashesh Jitendra Panchal

Masters Theses

"Since 2010 the US Environmental Protection Agency (EPA) has been proposing plans to study, and has now initiated research regarding the potential impact of hydraulic fracturing processes on drinking water sources. Their work refers to an 'Area of Evaluation' around a hydraulically fractured well, inferring that the wells immediately around hydraulic fractured wells should be studied, to evaluate the conditions of these wells and their potential to contaminate overlying USDWs. Class II injection wells must have a minimum 1/4 mile radius area of review to determine the condition of wells surrounding the proposed injection well. All wells within this AOR …

Parallel-Connected Solar Arrays, Majed Meshal Alabbass

Masters Theses

"The purpose of this thesis is to investigate the advantages of having various series-parallel configurations of solar arrays and make a comparison between them. The objective is to determine the best PV system configuration and thus improve the overall efficiency of a solar array. The primary focus of this thesis is to study the parallel connection of PV panels for achieving maximum efficiency while extracting maximum energy from the solar radiation. A comparison between a series connected and a parallel connected solar PV array justifies the need for installing a parallel configured solar PV array to achieve optimum performance. The …

Robust Methods For Construction Of Global Potential Energy Surfaces, Phalgun Lolur

Masters Theses

"This thesis is about the development of robust methods for construction of global potential energy surfaces to study the spectroscopy and dynamics of molecular systems. A potential energy surface represents the electronic energy of a molecule as a function of its geometry. This is central to how chemists view molecular systems in terms of motion across a rich energy landscape where barriers separate wells corresponding to different stable structures. The range of molecular distortions defines the potential energy surface. Computing the potential energy surface of a molecule has become a fundamental operation in modern theoretical chemistry studies. The Born-Oppenheimer approximation …

Assessment Of An Enterprise Employee Portal Using Dashboard Monitoring System: A Case Study, Aditi Mishra

Masters Theses

"A portal is a browser-based application that provides a web platform for users to improve inter-department collaboration and customer service. Portals are classified either as internal facing portals or external public facing portals. This study addresses the problems facing an internal portal related to its contents, functions and usability and provides a list of essential contents and functions that it should include through integrating theories and industry best practices. The theory framework is based on literature review and the industry best practices are based on the analysis of a number of internal portals of companies used as case studies. These …

Transmission Shaft Design For Hydrokinetic Turbine With Reliability Consideration, Goutham Pusapati

Masters Theses

"Hydrokinetic energy, a relatively new kind of renewable energy, can be generated from flowing water in rivers or oceans. Hydrokinetic turbines (HKTs) are a major system for hydrokinetic energy, and the reliability of the HKTs is critical for both their lifecycle cost and safety. The objective of this work is to apply advanced methodologies of reliability analysis and reliability-based design to the transmission shaft design for a horizontal-axis, non-submerged HKT. The deterministic shaft design is performed first by considering failure modes of strength and deflection using distortion energy, maximum shear and deflection theories. Then the reliability analysis of the shaft …

Hybridizing And Applying Computational Intelligence Techniques, Jeffery Scott Shelburg

Masters Theses

"As computers are increasingly relied upon to perform tasks of increasing complexity affecting many aspects of society, it is imperative that the underlying computational methods performing the tasks have high performance in terms of effectiveness and scalability. A common solution employed to perform such complex tasks are computational intelligence (CI) techniques. CI techniques use approaches influenced by nature to solve problems in which traditional modeling approaches fail due to impracticality, intractability, or mathematical ill-posedness. While CI techniques can perform considerably better than traditional modeling approaches when solving complex problems, the scalability performance of a given CI technique alone is not …

Liquid Phase Sintering Of 20bi(Zn₀.₅Ti₀.₅)O₃-80batio₃ Dielectrics With Bismuth-Zinc-Borate And Bismuth Borosilicate Glasses, David I. Shahin

Masters Theses

"Dielectrics in the Bi(Zn₀.₅Ti₀.₅O₃-BaTiO₃ system (specifically 20BZT-80BT, in mol%) are promising candidates for high energy density capacitor applications due to broad temperature-dependent dielectric constant maxima and a relatively field-independent permittivity. Bulk samples require sintering temperatures of greater than 1180ºC to reach useful densities. Due to incompatibility of Bi with low-pO₂ processing, BZT-BT-based multilayer capacitors must utilize noble metal electrodes that resist oxidation during sintering. Sintering temperatures must be reduced to allow use of less expensive electrode materials (Cu, etc.). This work studies the reduced temperature sintering behavior and dielectric properties of BZT-BT sintered with 30 Bi₂O₃-30ZnO-40B₂O₃ and 50Bi₂O₃-25B₂O₃-25SiO₂ (mol%) liquid …

Secure Design Defects Detection And Correction, Wenquan Wang

Masters Theses

"Bad design and software defects often make source codes hard to understand and lead to maintenance difficulties. In order to detect and fix such defects, researchers have systematically investigated these issues and designed different effective algorithms to tackle the problems. However, most of these methods need source codes/models for defect detection and correction. Commercial companies, like banks, may not be willing to provide their source models due to data security. Therefore, it is a huge challenge to detect software detects by a consulting company as well as to keep source models confidential. This thesis analyze security issues in existing approaches …

Lexis In Chemical Engineering Discourse: Analyzing Style In Chemical Engineering Research Articles Through A Rhetorical Lens, David Lamar Young

Masters Theses

"This study examines the style of chemical engineering research articles to discover stylistic trends that may be applicable to authors looking to publish their own research. Rhetorical stylistic analysis was used as a research method to allow for thorough analysis of all articles in the sample. Ten research articles from the two prominent chemical engineering journals were chosen using specific criteria to constitute a sample of articles that could most accurately represent the population of chemical engineering research articles. Each article was then analyzed line by line to identify markers of chemical engineering research article style, including the following: ▬Use …

Production Of 1,3-Propanediol From Glycerol Under Haloalkaline Conditions By Halanaerobium Hydrogeniformans, Daniel William Roush

Masters Theses

"With increased demands around the world to make modern lifestyles more environmentally friendly, the chemical commodity market has rapidly shifted. Through new technologies in chemical production, certain high value products have oversaturated the market and have become high-volume, low value waste products. The expansion of biodiesel production offers a prime example; high volumes of glycerol byproduct from this process have shifted glycerol from a high priced commodity to a common waste product. A number of microorganisms are known to synthesize the polymeric precursor 1,3-propanediol from glycerol; however, crude glycerol from biodiesel production creates a harsh environment for most microbes, and …

Harmonic Compensation In A Grid Using Doubly Fed Induction Generators, Omkar Amol Ghatpande

Masters Theses

"Ideally, electric utilities are expected to deliver a sinusoidal voltage with a constant rated frequency, while customers are expected to draw a sinusoidal current with unity power factor. The recent widespread use of harmonic producing equipment in industrial applications, especially non-linear loads, has increased the distortion of electric currents and voltages in transmission and distribution systems. This thesis proposes a method of using multiple reference frame theory for measuring and mitigating harmonic currents of nonlinear loads using a doubly fed induction generator. The most significant low-order harmonics to be compensated are calculated using a multiple reference frame harmonic observer. This …

Wetting And Drying Cycles And The Fungal Communities On Leaf Litter In Streams, Kele Qwinn Thrailkill

Masters Theses

"Leaf litter is a major source of energy for streams in deciduous forests. Fungi play a critical role by converting the leaves into nutritional material for the rest of the food web. The breakdown of leaf litter and associated biota, including invertebrates and fungi, have been proposed as measures of stream health in systems affected by anthropogenic activity. Rates of leaf breakdown can be depressed in streams affected by acidity, metals, organic contaminants, and other stressors. Climate change may lead to alterations in stream hydrology such that streams experience more frequent floods as well as drying episodes. Fungal communities can …

Insufficient Ct Data Reconstruction Based On Directional Total Variation (Dtv) Regularized Maximum Likelihood Expectation Maximization (Mlem) Method, Fahima Fahmida Islam

Masters Theses

"Sparse tomography is an efficient technique which saves time as well as minimizes cost. However, due to few angular data it implies the image reconstruction problem as ill-posed. In the ill posed problem, even with exact data constraints, the inversion cannot be uniquely performed. Therefore, selection of suitable method to optimize the reconstruction problems plays an important role in sparse data CT. Use of regularization function is a well-known method to control the artifacts in limited angle data acquisition. In this work, we propose directional total variation regularized ordered subset (OS) type image reconstruction method for neutron limited data CT. …

Examining The Efficiency Of Multimodal Transportation Systems: A Systems Dynamics Approach, Lizzette Pérez-Lespier

Masters Theses

"With international trade becoming a big part of the world's economic activity, the demand for good freight transportation systems has grown substantially. The appropriate use of transportation is an integral part of the supply chain's effectiveness. Therefore, the continuous economic globalization, the growing demand for speed-to-market product delivery, and the need to manage global supply chains more effectively, has led to the sustained increase in demand towards multimodal transportation systems (MTS). MTS play an essential role in corporations competing in global markets in the 21st century. In transportation, the effectiveness and efficiency of the whole system depends upon the interconnectivity …

Provenance Framework For Mhealth, Aarathi Prasad, Ronald Peterson, Shrirang Mare, Jacob Sorber, Kolin Paul, David Kotz

Dartmouth Scholarship

Mobile health technologies allow patients to collect their health information outside the hospital and share this information with others. But how can data consumers know whether to trust the sensor-collected and human-entered data they receive? Data consumers might be able to verify the accuracy and authenticity of the data if they have information about its origin and about changes made to it, i.e., the \emphprovenance\/ of the data. We propose a provenance framework for mHealth devices, to collect and share provenance metadata and help the data consumer verify whether certain provenance properties are satisfied by the data they receive. This …

Supply Chain Management And Lean Six Sigma In A Retail Environment, Brittain Cliff Ladd

Apparel Design and Hospitality Management

This qualitative research evaluated the as-is supply chain management and logistics retail processes of Dell, a manufacturing company that also has retail operations globally. Dell has an online channel capable of serving millions of customers annually. This research focused on Dell’s retail operations in Canada and the United States and the challenges of managing the supply chain requirements of meeting customer demand. The goal was to identify issues with process execution leading to decreased service to customers and increased costs to the manufacturer. A literature review provided information regarding best practices in supply chain management and the leading process-improvement methodology. …

Spatial And Temporal Trends Of Snowfall In Central New York - A Lake Effect Dominated Region, Justin Joseph Hartnett

USF Tampa Graduate Theses and Dissertations

Central New York is located in one of the snowiest regions in the United States, with the city of Syracuse, New York the snowiest metropolis in the nation. Snowfall in the region generally begins in mid-November and lasts until late-March. Snow accumulation occurs from a multitude of conditions: frontal systems, mid-latitude cyclones, Nor'easters, and most notably lake-effect storms. Lake effect snowfall (LES) is a difficult parameter to forecast due to the isolated and highly variable nature of the storm. Consequently, studies have attempted to determine changes in snowfall for lake-effect dominated regions. Annual snowfall patterns are of particular concern as …

Evaluation Of Four Portable Cooling Vests For Workers Wearing Gas Extraction Coveralls In Hot Environments, Joseph Kevin Johnson

USF Tampa Graduate Theses and Dissertations

Excessive exposure to heat stress can cause a host of heat-related illnesses. For laborers, job specific work demands and protective garments greatly increase the risk of succumbing to the effects of heat stress. Microclimate cooling has been used to control heat stress exposure where administrative or engineering controls are not adequate. This study tested the performance of four personal cooling vests for use with insulated protective clothing (gas extraction coveralls) in warm-humid (35 ° C, 50% relative humidity) and hot-dry (40°C, 30% relative humidity) conditions. On 10 separate occasions, 5 male volunteers walked on a treadmill to elicit a target …

Spin Dependent Transport In Novel Magnetic Heterostructures, Priyanga Buddhika Jayathilaka

USF Tampa Graduate Theses and Dissertations

Magnetic oxides have become of interest source for spin transport devices due to their high spin polarization. But the real applications of these oxides remains unsatisfactory up to date, mostly due to the change of properties as a result of nano structuring. Magnetite (Fe₃O₄) is one such a material. High Curie temperature and the half metallicity of Fe₃O₄ make it a good potential candidate for spin transport devices. Studies have shown that the nano structuring Fe₃O₄ changes most of it's important properties. This includes high saturation magnetization and drop of …

Bayesian Estimation Of Panel Data Fractional Response Models With Endogeneity: An Application To Standardized Test Rates, Lawrence Kessler

USF Tampa Graduate Theses and Dissertations

In this paper I propose Bayesian estimation of a nonlinear panel data model with a fractional dependent variable (bounded between 0 and 1). Specifically, I estimate a panel data fractional probit model which takes into account the bounded nature of the fractional response variable. I outline estimation under the assumption of strict exogeneity as well as when allowing for potential endogeneity. Furthermore, I illustrate how transitioning from the strictly exogenous case to the case of endogeneity only requires slight adjustments. For comparative purposes I also estimate linear specifications of these models and show how quantities of interest such as marginal …

Effect Of Solids Retention Time On The Denitrification Potential Of Anaerobically Digested Swine Waste, Maureen Njoki Kinyua

USF Tampa Graduate Theses and Dissertations

Three continuously stirred tank reactors (CSTR) were operated in semi continuous mode treating swine waste using anaerobic digestion. The reactors were used to test the effect of solid retention time (SRT) on CH4 yield, total ammonia nitrogen (TAN) concentrations, % volatile solids (VS), chemical oxygen demand (COD) and volatile fatty acids (VFA) removal, readily biodegradable COD concentration and the denitrification potential for the effluent in a biological nutrient removal (BNR) system. During Phase I of the study, the three reactors were operated at the same 28 day SRT for 16 weeks. SRTs were then changed during the 12 week Phase …

A Rheological Examination Of Polymer Composites: Including Functionalized Carbon Nanotubes, Viable Polyurethane Alternates, And Contact Lens Hydrogels, Bernard Knudsen

USF Tampa Graduate Theses and Dissertations

From medicine to aerospace, innovation in multiple fields will not occur without addressing current questions that still exist in polymer behavior and manipulation. This dissertation represents the research carried out over the course of three separate experiments using rheometry as the key technique to explore the behavior of polymer composites. In all three studies, polymer composites were investigated for changes to their known physical properties caused through the addition of a filler or functionalization.

Chapter Two examines the possibility of enhancing poly(4-methyl-1-pentene) through the use of soluble carbon nanotubes. In this series of experiments, carbon nanotubes were covalently functionalized using …

Do Personality Tests Have A Place In Academic Preparation Of Undergradute Hospitality Students, Gunce Malan

USF Tampa Graduate Theses and Dissertations

This is a descriptive study that poses the questions and discussion regarding use of personality tests in prediction of future job performance of the current undergraduate hospitality students. A gap exists between the perception of the skills and competencies of high performers and the perception of hospitality students (Berezina et al., 2011; Malan, Berezina & Cobanoglu, 2012). The purpose of this study is to investigate if personality tests will help in predicting the success of students in their preferred job setting as compared to current high performers (managers).

The use of personality tests increased substantially after 1988, when the government …

Biochemical Aspects Of The Thermal Sensitivity And Energy Balance Of Polar, Tropical And Subtropical Teleosts, Eloy Martinez

USF Tampa Graduate Theses and Dissertations

The maintenance of a functional energy balance in ectothermic fauna could be challenging in a thermally disparate environment. Biochemical adaptations at the enzyme and membrane levels allows for a set compensatory mechanism that allow the individual to maintain an energetic surplus, thus allocating energy for growth and reproduction. The present work describes how the energetic machinery in the cell, particularly the mitochondrion, could be affected by temperature changes. More specifically, this work aimed to determine how environmental temperature affects the mitochondria energetic performance of fishes from disparate thermal regimes.

Mitochondrial ATP production efficiency was evaluated in fishes from polar, tropical …

Reaction Enthalpy And Volume Profiles For Excited State Reactions Involving Electron Transfer And Proton-Coupled Electron Transfer, William Antonio Maza

USF Tampa Graduate Theses and Dissertations

Electron transfer, ET, and proton-coupled electron transfer, PCET, reactions are central to biological reactions involving catalysis, energy conversion and energy storage. The movement of electrons and protons in either a sequential or concerted manner are coupled in a series of elementary reaction steps in respiration and photosynthesis to harvest and convert energy consumed in foodstuffs or by absorption of light into high energy chemi-cal bonds in the form of ATP. These electron transfer processes may be modulated by conformational dynamics within the protein matrix or at the protein-protein interface, the energetics of which are still not well understood. Photoacoustic calorimetry …

Development Of Novel Nano-Composite Membranes As Introduction Systems For Mass Spectrometers: Contrasting Nano-Composite Membranes And Conventional Inlet Systems, Luis Miranda

USF Tampa Graduate Theses and Dissertations

This dissertation presents the development of novel nano-composite membranes as introduction systems for mass spectrometers. These nano-composite membranes incorporate anodic aluminum oxide (AAO) membranes as templates that can be used by themselves or modified by a variety of chemical deposition processes. Two types of nano-composite membranes are presented. The first nano-composite membrane has carbon deposited within the pores of an AAO membrane. The second nano-composite membrane is made by coating an AAO membrane with a thin polymer film. The following chapters describe the transmission properties these nano-composite membranes and compare them to conventional mass spectrometry introduction systems. The nano- composite …

Reliability Assessment Of Ion Contamination Residues On Printed Circuit Board, Minh Tam Tran Nguyen

USF Tampa Graduate Theses and Dissertations

Ion contaminants from Printed Circuit Board (PCB) assembly processes pose a high reliability risk because they result in damaged circuits. Therefore, it is essential to understand the level of ionic species on the electronic circuitry as well as the reliability risks caused by these contaminants. There are a number of approaches available in the industry to assess the reliability risks ; for example, the water drop test (WDT) is one of the techniques used to determine the propensity of an ionic contaminant to cause electrical short failures by dendrite formation. The objective of this research is to determine the time …

Dynamic Processes In Network Goods: Modeling, Analysis And Applications, Arnut Paothong

USF Tampa Graduate Theses and Dissertations

The network externality function plays a very important role in the study of economic network industries. Moreover, the consumer group dynamic interactions coupled with network externality concept is going to play a dominant role in the network goods in the 21st century. The existing literature is stemmed on a choice of externality function with certain quantitative properties. The utility function coupled with the network externality function is used to investigate static properties of rational equilibrium. The aim of this work is to systematically initiate a development of quantitative effects of the concept of network externality and its influence on the …