Physical Sciences and Mathematics Commons^™

Application Of Colloidal Unimolecular Polymer (Cup) Particles In Coatings, Sagar Vijay Gade

Doctoral Dissertations

"Colloidal unimolecular polymer (CUP) particles were prepared by the process of water reduction on copolymers containing hydrophobic and hydrophilic monomers at definite ratio using free radical polymerization. The CUPs are formed by the effect of hydrophilic /hydrophobic interactions of the polymer with a change in the solvent environment around them. Once formed these colloidal particles are thermodynamically stable with collapsed hydrophobic groups forming a spheroidal core and hydrophilic charges on the surface stabilizing the particle by the charge repulsion. CUPs contain only the charged CUP particles, water and counterions with all the functionality on the surface for further chemistry. CUP …

Enhanced Lasso Recovery On Graph, Xavier Bresson, Thomas Laurent, James Von Brecht

Mathematics, Statistics and Data Science Faculty Works

This work aims at recovering signals that are sparse on graphs. Compressed sensing offers techniques for signal recovery from a few linear measurements and graph Fourier analysis provides a signal representation on graph. In this paper, we leverage these two frameworks to introduce a new Lasso recovery algorithm on graphs. More precisely, we present a non-convex, non-smooth algorithm that outperforms the standard convex Lasso technique. We carry out numerical experiments on three benchmark graph datasets.

A Stochastic Model For Microbial Fermentation Process Under Gaussian White Noise Environment, Yanping Ma

Mathematics, Statistics and Data Science Faculty Works

In this paper, we propose a stochastic model for the microbial fermentation process under the framework of white noise analysis, where Gaussian white noises are used to model the environmental noises and the specific growth rate is driven by Gaussian white noises. In order to keep the regularity of the terminal time, the adjustment factors are added in the volatility coefficients of the stochastic model. Then we prove some fundamental properties of the stochastic model: the regularity of the terminal time, the existence and uniqueness of a solution and the continuous dependence of the solution on the initial values.

Solving The Ko Labyrinth, Alissa Crans, Robert J. Rovetti

Mathematics, Statistics and Data Science Faculty Works

The KO Labyrinth is a colorful spherical puzzle with 26 chambers, some of which can be connected via holes through which a small ball can pass when the chambers are aligned correctly. The puzzle can be realigned by performing physical rotations of the sphere in the same way one manipulates a Rubik’s Cube, which alters the configuration of the puzzle. The goal is to navigate the ball from the entrance chamber to the exit chamber. We find the shortest path through the puzzle using Dijkstra’s algorithm and explore questions related to connectivity of puzzle with the adjacency matrix, distance matrix, …

A New Characterization Of Fine Scale Diffusion On The Cell Membrane, Flor A. Espinoza, Stanly L. Steinberg

Faculty Articles

We use a large single particle tracking data set to analyze the short time and small spatial scale motion of quantum dots labeling proteins in cell membranes. Our analysis focuses on the jumps which are the changes in the position of the quantum dots between frames in a movie of their motion. Previously we have shown that the directions of the jumps are uniformly distributed and the jump lengths can be characterized by a double power law distribution. Here we show that the jumps over a small number of time steps can be described by scalings of a single double …

The Effect Of Spatial Patterns Of Soil Hydraulic Conductivity And Depth On Local And Hillslope Scale Shallow Water Table Dynamics, Casey E. Ryan

Graduate Student Theses, Dissertations, & Professional Papers

Much research in forested headwater catchments has focused on the role of topography for organizing subsurface flow and the hydrologic connectivity of upland flow paths to stream networks. However, little work has been conducted to evaluate how localized and hillslope scale patterns of hydraulic conductivity and soil depth contribute to spatial patterns of water table duration, magnitude, and connectivity. I monitored shallow groundwater dynamics in wells distributed across a 1st order hillslope in the Lubrecht Experimental Forest, Montana. Additionally, I collected in-situ measurements of soil saturated hydraulic conductivity and soil depth at 10m intervals across the study hillslope and compared …

Interpretation Of Complexometric Titration Data: An Intercomparison Of Methods For Estimating Models Of Trace Metal Complexation By Natural Organic Ligands, I. Pižeta, S. G. Sander, R. J. M. Hudson, D. Omanović, O. Baars, K. A. Barbeau, K. N. Buck, R. M. Bundy, G. Carrasco, P. L. Croot

OES Faculty Publications

With the common goal of more accurately and consistently quantifying ambient concentrations of free metal ions and natural organic ligands in aquatic ecosystems, researchers from 15 laboratories that routinely analyze trace metal speciation participated in an intercomparison of statistical methods used to model their most common type of experimental dataset, the complexometric titration. All were asked to apply statistical techniques that they were familiar with to model synthetic titration data that are typical of those obtained by applying state-of-the-art electrochemical methods – anodic stripping voltammetry (ASV) and competitive ligand equilibration-adsorptive cathodic stripping voltammetry (CLE-ACSV) – to the analysis of natural …

Sparse Representation Based Classification: Towards Efficiency And Accuracy, Soheil Shafiee

Computer Science and Engineering Dissertations

With the fast growing deployment of machine intelligence in several real-life applications, there are always increasing needs for faster and more precise machine learning algorithms, especially classification and object recognition. One of the most recent methods proposed for this purpose is Sparse Representation-based Classification (SRC) which works based on the emerging theory of Compressive Sensing. SRC shows excellent classification results in comparison to many well-known classification approaches. However, despite its high recognition power, SRC suffers from high computational and memory costs as it directly uses all original ground truth data as representatives to build its training model. Given high recognition …

Considerations For Screening Designs And Follow-Up Experimentation, Robert D. Leonard

Theses and Dissertations

The success of screening experiments hinges on the effect sparsity assumption, which states that only a few of the factorial effects of interest actually have an impact on the system being investigated. The development of a screening methodology to harness this assumption requires careful consideration of the strengths and weaknesses of a proposed experimental design in addition to the ability of an analysis procedure to properly detect the major influences on the response. However, for the most part, screening designs and their complementing analysis procedures have been proposed separately in the literature without clear consideration of their ability to perform …

Experimental Investigation Of Encapsulated Phase Change Materials For Thermal Energy Storage, Tanvir E. Alam

USF Tampa Graduate Theses and Dissertations

Thermal energy storage (TES) is one of the most attractive and cost effective solutions to the intermittent generation systems like solar, wind and other renewable sources, compared to alternatives. It creates a bridge between the power supply and demand during peak hours or at times of emergency to ensure the continuous supply of energy. Among all the TES systems, latent heat thermal energy storage (LHTES) draws lots of interests as it has high energy density and can store or retrieve energy isothermally. Two major technical challenges associated with the LHTES are low thermal conductivity of the phase change materials (PCMs), …

Sound Attenuation Performance Of Fiber-Reinforced Polymer Composite Circumaural Hearing Protection Devices, Steven Christopher Augustine

USF Tampa Graduate Theses and Dissertations

Personnel who work on the flight deck of an aircraft carrier are exposed to extreme levels of jet engine noise often in excess of 140 decibels (dB). The current circumaural hearing protective devices (CAHPD) employed by flight deck crewmen are inadequate for the level of protection required for these extreme levels of noise. Fiber-reinforced thermoset polymer composite (FRPC) materials such as aramid fibers used in body armor, have high theoretical values of acoustic impedance due to a fundamentally high modulus of elasticity and may offer a superior level of hearing protection over original equipment (OE) thermoplastic CAHPDs. The objective of …

The Use Of Textural Kinetic Habitats To Mine Diagnostic Information From Dce Mr Images Of Breast Tumors, Baishali Chaudhury

USF Tampa Graduate Theses and Dissertations

Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) of the breast is a widely used non-invasive approach to gather information about the underlying physiology of breast tumors. Recent studies indicate that breast tumor heterogeneity may reflect the presence of different levels of cellular aggressiveness or habitats within the tumor. This heterogeneity has been correlated to the variations in the contrast enhancement patterns within the tumor apparent on gadolinium-enhanced DCE-MRI. Although pathological and qualitative (based on contrast enhancement patterns) studies suggest the presence of clini- cal and molecular predictive tumor sub-regions, this has not been fully investigated in the quantitative domain.

The …

Achieving Reliable Generation \& Delivery Of Energy Through Robust Optimization, Anna Danandeh

USF Tampa Graduate Theses and Dissertations

In this dissertation, we elaborate on the inherent risks and uncertainties in power systems and associated industries, and develop practical solution methods to eliminate their adverse effects.

our research agenda consists of practice-driven problems in different stages of power generation as follows. (1) Affordable fuel procurement through developing a comprehensive fuel supply chain design and operations planning system for electricity generation companies, (2) reliable electricity generation through incorporating dynamic asset rating concept in the unit commitment problem, and (3) efficient demand management through proposing a job scheduling model for effective local generation consumption.

Since reliability cannot be compromised in energy …

Analysis Of Carbon Policies For Electricity Networks With High Penetration Of Green Generation, Felipe Feijoo

USF Tampa Graduate Theses and Dissertations

In recent decades, climate change has become one of the most crucial challenges for humanity. Climate change has a direct correlation with global warming, caused mainly by the green house gas emissions (GHG). The Environmental Protection Agency in the U.S. (EPA) attributes carbon dioxide to account for approximately 82\% of the GHG emissions. Unfortunately, the energy sector is the main producer of carbon dioxide, with China and the U.S. as the highest emitters. Therefore, there is a strong (positive) correlation between energy production, global warming, and climate change. Stringent carbon emissions reduction targets have been established in order to reduce …

Effects Of Solids Retention Time And Feeding Frequency On Performance And Pathogen Fate In Semi-Continuous Mesophilic Anaerobic Digesters, Nathan Daniel Manser

USF Tampa Graduate Theses and Dissertations

Anaerobic digestion is a biochemical process in which organic carbon is biodegraded in an oxygen free environment through a microbial consortium. Engineered biological systems used for resource recovery often utilize anaerobic digestion to treat anthropogenic organic wastes by reclaiming the carbon as energy (methane gas) and a soil amendment (biosolids). Small-scale, or household, semi-continuous anaerobic digesters have been used in developed and developing countries for many decades to produce biogas from human and livestock waste, which is used for heating, lighting, and cooking. This application has been shown to improve the quality of life of the user. Although there is …

Assessment Of Public Health Risks Associated With Petrochemical Emissions Surrounding An Oil Refinery, Erin L. Pulster

USF Tampa Graduate Theses and Dissertations

Refinery operations have been associated with a wide variety of atmospheric emissions consisting of criteria air pollutants, volatile organic components, hazardous air pollutants as well as other pollutants. With approximately 100 oil refineries in the Wider Caribbean region (WCR), hydrocarbons in this region pose significant environmental and human health risks. One of the oldest and largest refineries in the WCR is the Isla Refineriá, which is located on the island of Curaçao, and has been the basis of historical debates and conflict between the public and the local government over the environmental and human health risks. This research aims to …

Theoretical Investigations Of Gas Sorption And Separation In Metal-Organic Materials, Tony Pham

USF Tampa Graduate Theses and Dissertations

Metal--organic frameworks (MOFs) are porous crystalline materials that are synthesized from rigid organic ligands and metal-containing clusters. They are highly tunable as a number of different structures can be made by simply changing the organic ligand and/or metal ion. MOFs are a promising class of materials for many energy-related applications, including H₂ storage and CO₂ capture and sequestration. Computational studies can provide insights into MOFs and the mechanism of gas sorption and separation. Theoretical studies on existing MOFs are performed to determine what structural characteristics leads to favorable gas sorption mechanisms. The results from these studies can provide …

2,4-Disubstituted Quinazolines With Antileishmanial Or Antibacterial Activity, Megan Marie Barber

USF Tampa Graduate Theses and Dissertations

Herein 47 2,4-disubstituted quinazolines were synthesized and tested against Leishmania donovani intracellular amastigotes. A structure-activity relationship was conducted and lead to the identification of quinazolines with EC50s in the single digit and high nanomolar range with favorable antileishmanial selectivity indexes. Quinazoline 2.6 and 2.31 underwent in vivo efficacy studies in murine models of visceral leishmaniasis, reducing liver parasitemia by 12 % and 24 %, respectively, when given by the intraperitoneal route at 15 mg/kg/day x 5 days. The antileishmanial efficacy and easy of synthesis make the 2,4-disubstituted quinazoline compound series a suitable platform for the future development of antileishmanial agents. …

Glaciological Applications Of Terrestrial Radar Interferometry, Denis Voytenko

USF Tampa Graduate Theses and Dissertations

Terrestrial Radar Interferometry (TRI) is a relatively new ground-based technique that combines the precision and spatial resolution of satellite interferometry with the temporal resolution of GPS. Although TRI has been applied to a variety of fields including bridge and landslide monitoring, it is ideal for studies of the highly-dynamic terminal zones of marine-terminating glaciers, some of which are known to have variable velocities related to calving and/or ocean-forced melting. My TRI instrument is the Gamma Portable Radar Interferometer, which operates at 17.2 GHz (1.74 cm wavelength), has two receiving antennas for DEM (digital elevation model) generation, and images the scenes …

Endocrine-Disrupting Compounds: Measurement In Tampa Bay, Removal From Sewage And Development Of An Estrogen Receptor Model, Monica Mion Cook

USF Tampa Graduate Theses and Dissertations

The significance of endocrine-disrupting compounds (EDCs) in the environment has only recently come to the forefront of scientific research, policy debates, water utilities management and public awareness. EDCs have the ability to interfere with the normal functioning of the endocrine system of humans and other animals. Numerous chemicals are included in the class of compounds known as EDCs, and exposure is widespread. These compounds are found in a variety of environmental matrices (e.g., marine and freshwater systems, sediment, soil), transported there primarily through sewage effluent discharge and recycling of sewage sludge for topical fertilizer use. This transport to the environment …

A Composite Spatial Model Incorporating Groundwater Vulnerability And Environmental Disturbance To Guide Land Management, Johanna L. Kovarik

USF Tampa Graduate Theses and Dissertations

Research has long recognized and studied the dynamics of groundwater processes. More recently, groundwater dependent ecosystems (GDEs) are being recognized for their diversity and vulnerability to anthropogenic impact. Groundwater in karst landscapes presents a distinctive situation where flow through the subsurface often moves rapidly on the scale of days and weeks as opposed to years or millennia in other systems. This distinctive situation of karst systems and their vulnerability to human impacts necessitate an integrated and multifaceted approach for the management of these important resources. However, development of such an approach is complicated by the difficulty of obtaining detailed data …

Enhanced Magnetoimpedance And Microwave Absorption Responses Of Soft Ferromagnetic Materials For Biodetection And Energy Sensing, Jagannath Devkota

USF Tampa Graduate Theses and Dissertations

A combination of magnetic sensors with magnetic nanoparticles offers a promising approach for highly sensitive, simple, and rapid detection of cancer cells and biomolecules. The challenge facing the field of magnetic biosensing is the development of low-cost devices capable of superconducting quantum interference device (SQUID)-like field sensitivity at room temperature. In another area of interest, improving the sensitivity of existing electromagnetic field sensors for microwave energy sensing applications is an important and challenging task. In this dissertation, we have explored the excellent magnetoimpedance and microwave absorption responses of soft ferromagnetic amorphous ribbons and microwires for the development of high-performance magnetic …

Statistical Learning With Artificial Neural Network Applied To Health And Environmental Data, Taysseer Sharaf

USF Tampa Graduate Theses and Dissertations

The current study illustrates the utilization of artificial neural network in statistical methodology. More specifically in survival analysis and time series analysis, where both holds an important and wide use in many applications in our real life. We start our discussion by utilizing artificial neural network in survival analysis. In literature there exist two important methodology of utilizing artificial neural network in survival analysis based on discrete survival time method. We illustrate the idea of discrete survival time method and show how one can estimate the discrete model using artificial neural network. We present a comparison between the two methodology …

New Tracer To Estimate Community Predation Rates Of Phagotrophic Protists, Alexander B. Bochdansky, Melissa A. Clouse

OES Faculty Publications

Predation of eukaryotic microbes on prokaryotes is one of the most important trophic interactions on Earth, representing a major mortality term and shaping morphology and composition of prokaryotic communities. Here we introduce and validate a new tracer to determine predation rates on prokaryotes. Minicells of Escherichia coli marked with a bright green fluorescent protein (GFP) vector have many operational advantages over previously used prey analogs such as fluorescently labeled bacteria. GFP-minicells are similar in size to naturally occurring bacteria from a variety of environments including the oligotrophic open ocean and the deep sea. They are relatively stable against microbial and …

How Do Personal Connections Play A Role In Risk Perception Of Climate Change And Sea Level Rise?, Katelyn Sheeley

OUR Journal: ODU Undergraduate Research Journal

The threat of sea level rise is unknown to many coastal residents living in the United States, including Virginians. Climate Central, a nonprofit research-based organization, has created the Risk Finder tool to help inform the public about the potential dangers posed by sea level rise. Risk Finder is an interactive, online mapping tool intended to inform residents of useful data concerning sea level rise. Dr. Daniel Richards and Mrs. Megan Mckittrick from Old Dominion University acted as primary investigators for a study of the Risk Finder tool, serving client Dan Rizza of Climate Central. Students of ENGL 231C served as …

Livestock Production From Grasslands With Improved Management Compared To Traditional Management, Florian Leiber

IGC Proceedings (1993-2023)

The value of traditional versus improved management systems for grassland is discussed. The set target is the persistence of the ecological, economic and social multifunctionality of grasslands and the increase of food output from these areas without increasing parallel requirements for arable crop or energy inputs. Based on the fact that historically traditional systems were stable and sustainable in many cases, while severe damage is faced nowadays, it is argued that lot of improvement should be based on the acknowledgment of successful traditional practises. The challenge might rather be to define improvement as a contemporary development of traditional techniques. The …

Mapping Robinia Pseudoacacia Forest Health Conditions By Using Combined Spectral, Spatial, And Textural Information Extracted From Ikonos Imagery And Random Forest Classifier, Hong Wang, Yu Zhao, Ruiliang Pu

School of Geosciences Faculty and Staff Publications

The textural and spatial information extracted from very high resolution (VHR) remote sensing imagery provides complementary information for applications in which the spectral information is not sufficient for identification of spectrally similar landscape features. In this study grey-level co-occurrence matrix (GLCM) textures and a local statistical analysis Getis statistic (Gi), computed from IKONOS multispectral (MS) imagery acquired from the Yellow River Delta in China, along with a random forest (RF) classifier, were used to discriminate Robina pseudoacacia tree health levels. Specifically, eight GLCM texture features (mean, variance, homogeneity, dissimilarity, contrast, entropy, angular second moment, and correlation) were first calculated from …

Multi-Year Observations Of Breiðamerkurjökull, A Marine-Terminating Glacier In Southeastern Iceland, Using Terrestrial Radar Interferometry, Denis Voytenko, Timothy H. Dixon, Ian M. Howat, Noel Gourmelen, Chad Lembke, Charles L. Werner, Santiago De La Peña, Björn Oddsson

School of Geosciences Faculty and Staff Publications

Terrestrial radar interferometry (TRI) is a new technique for studying ice motion and volume change of glaciers. TRI is especially useful for temporally and spatially dense measurements of highly dynamic glacial termini. We conducted a TRI survey of Breiðamerkurjökull, a marine-terminating glacier in Iceland, imaging its terminus near the end of the melt season in 2011, 2012 and 2013. The ice velocities were as high as 5 m d−1, with the fastest velocities near the calving front. Retreat of the glacier over the 3 year observation period was accompanied by strong embayment formation. Iceberg tracking with the radar shows high …

Self-Reported Experiences Of Climate Change In Nigeria: The Role Of Personal And Socio-Environmental, Idowu Ajibade, Frederick Ato Armah, Vincent Kuuire, Isaac Luginaah, Gordon Mcbean

Geography Faculty Publications and Presentations

In this study, we examined the individual and socio-environmental factors that mediate differential self-reported experiences of climate change in coastal communities in Lagos, Nigeria. Binary complementary log-log multivariate regression was used to model residents’ experiences of changing rainfall patterns, ocean surges, and flood events. An analysis of both compositional and contextual factors showed that there were urban communities where vulnerability to flooding tends to be clustered, and that this was not fully explained by the characteristics of the people of whom the community was composed. This study, thus, underscores the importance and complex nature of the interaction between personal and …

Discourses Of Deflection: The Politics Of Framing China’S South North Water Transfer Project, Britt Crow-Miller

Geography Faculty Publications and Presentations

Despite significant financial, ecological and social trade-offs, China has moved forward with constructing and operationalising the world’s largest interbasin water transfer project to date, the South-North Water Transfer Project (SNWTP). While it is fundamentally linked to broader political-economic goals within the context of China’s post-Mao development agenda, the SNWTP is frequently discussed in apolitical terms. Based on extensive discourse analysis and interviews with government officials across North China, I argue that the Chinese government is using "discourses of deflection" to present the project as politically neutral in order to serve its ultimate goal of maintaining the high economic growth rates …