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Development Of Watershed-Based Modeling Approach To Pollution Source Identification, Yangbin Tong

LSU Master's Theses

Identification of unknown pollution sources is essential to environmental protection and emergency response. A review of recent publications in source identification revealed that there are very limited numbers of research in modeling methods for rivers. What’s more, the majority of these attempts were to find the source strength and release time, while only a few of them discussed how to identify source locations. Comparisons of these works indicated that a combination of biological, mathematical and geographical method could effectively identify unknown source area(s), which was a more practical trial in a watershed. This thesis presents a watershed-based modeling approach to …

Reaction Of Green Leaf Volatiles As A Source Of Secondary Organic Aerosols In Fog Droplets, Amie Kathryn Hansel

LSU Master's Theses

Green leaf volatiles (GLVs) are a group of biogenic volatile organic compounds (BVOCs) released into the atmosphere by vegetation when plants undergo stress or mechanical damage. BVOCs produce secondary organic aerosol (SOA) in the gas phase; however, their oxidation as a source of SOA in the liquid phase has not been investigated. Once released into the atmosphere, water-soluble GLVs partition into atmospheric water phases such as fog, mist, dew or rain, where they are oxidized by hydroxyl radicals (ÿOH). Photochemical oxidation yields products that are higher in molecular weight, more polar, more oxygenated, and lower in vapor pressure. When the …

Erosional Resistance Of Cohesive Sediments In Coastal Saltmarshes, Hem Raj Pant

LSU Master's Theses

Louisiana’s saltmarshes, one of the most productive wetlands in the nation, are undergoing severe erosion due to hydrodynamic forces (storm surge) and sea level rise. The erosional behavior of coastal saltmarshes, which possess cohesive sediments as their integral components, are very difficult to analyze and understand. The erosional resistance of cohesive sediments determines the stability and sustainability of coastal wetlands. This erosional resistance is expressed as an erosion threshold or critical shear stress, which depends on various soil properties (e.g. water content, root content, organic matter content, and pore water salinity) affecting saltmarsh erodibility integratively. A cohesive strength meter was …

Effect Of Microwave Heating On The Migration Of Additives From Ps, Pp And Pet Container Into Food Simulants, Ruoyin Cai

Theses

Microwave food packaging has become a tremendous element in the food manufacturing process. The purpose of any food packaging regulations concerned with the safety of the food is to control and limit the migration of substances from the packaging into the food. The main objective of this thesis is to test three different microwaving packaging materials that are the most common material in the market, viz. polystyrene (PS), polypropylene (PP), and polyethylene terephthalate (PET), migrated into four food simulant solutions. Four different simulant solutions were used based on the food type and FDA recommendations and regulations. These food simulants include …

Modeling And Design Of Photocatalytic Reactors For Air Purification, Yangyang Zhang

USF Tampa Graduate Theses and Dissertations

Photocatalysis is a promising technique for the remediation of indoor air pollution. Photocatalysis utilizes semiconductor photocatalysts (such as TiO₂ or ZnO) and appropriate light to produce strong oxidizing agents (OH*) that are able to break down organic compounds and inactivate bacteria and viruses. The overall goal of the research is to develop an efficient photocatalytic reactor based on mass transfer for indoor air purification. This study has focused on the enhancement of the effectiveness of the photocatalytic process by the introduction of artificial roughness on the reactor catalyst surface. The major effect of artificial roughness elements on the catalytic …

Model Pt- And Pd-Based Electrocatalysts For Low Temperature Fuel Cells Applications, Selasi Ofoe Blavo

USF Tampa Graduate Theses and Dissertations

In the search for alternative energy technologies, low temperature fuel cells continue to feature as technologies with the most promise for mass commercialization. Among the low temperature fuel cells, alkaline and proton exchange membrane fuel cells are the most popular. Alkaline fuel cells have typically been used for water generation as well as auxiliary power for space shuttles. Their bulkiness however makes them undesirable for other applications, especially in automobiles, where there is a great demand for alternative technologies to internal combustion engines. Proton exchange membrane fuel cells on the other hand possess numerous qualities including their compact size, high …

An Acoustic-Based Microfluidic Platform For Active Separation And Mixing, Myeong Chan Jo

USF Tampa Graduate Theses and Dissertations

Particle separation is of great interest to many biological and biomedical applications. Flow-based methods have been used to sort particles and cells. However, the main challenge with flow based particle separation systems is the need for a sheath flow for successful operation. Existence of the sheath liquid dilutes the analyte, necessitates precise flow control between sample and sheath flow, requires a complicated design to create sheath flow and separation efficiency depends on the sheath liquid composition. In addition, current gold standard active separation techniques are only capable of separation based on particle size; hence, separation cannot be achieved for same-size …

Fabricating And Characterizing Physical Properties Of Electrospun Polypeptide-Based Nanofibers, Dhan Bahadur Khadka

USF Tampa Graduate Theses and Dissertations

This dissertation has aimed to fabricate polypeptide based biomaterial and characterize physical properties. Electrospinning is used as a tool for the sample fabrication. Project focused on determining the feasibility of electrospinning of certain synthetic polypeptides and certain elastin-like peptides from aqueous feedstocks and to characterize physical properties of polymer aqueous solution, cast film and spun fibers and fiber mats. The research involves peptide design, polymer electrospinning, fibers crosslinking, determining the extent of crosslinking, fibers protease degradation study, fibers stability and self-organization analysis, structure and composition determination by various spectroscopy and microscopy techniques and characterization of mechanical properties of individual suspended …

Modeling Nitrogen Transformations In A Pilot Scale Marine Integrated Aquaculture System, Brian Mccarthy

USF Tampa Graduate Theses and Dissertations

Integrated aquaculture systems (IAS) are a type of recirculating aquaculture systems (RAS) where the wastewater is treated and returned to the fish tanks. The important difference between the two is that in an IAS, wastes from the aquaculture component are recovered as fertilizer to produce an agricultural product whereas in an RAS, waste organics, nutrients and solids are treated and discharged. A pilot marine IAS at Mote Aquaculture Research Park in Sarasota, FL was studied for this project. Water quality monitoring, measurements of fish health and growth rates of fish and plants were performed over a two-year period to determine …

Quantifying The Ergonomic Impact On Healthcare Workers Using A Needle-Free Injector Device, Humberto Jose Olivero Lara

USF Tampa Graduate Theses and Dissertations

Background: Jet injectors are advantageous over needle injectors by eliminating sharps hazards. The Government Accountability Office estimates 29% preventable sharp injuries with an estimated direct cost of more than $500 million out of the CDC's reported incidence of 385,000 needle stick injuries per year among US hospital healthcare workers. Yet the forces required to set and trigger devices using spring mechanisms for medication delivery have not been explored. This laboratory experiment measured forces exerted by healthcare workers (HCWs) using a particular jet injector approved by FDA in 2011.

Objectives: In order to quantify the ergonomic impact on HCWs using a …

Magnetization Dynamics And Related Phenomena In Nanostructures, Sayan Chandra

USF Tampa Graduate Theses and Dissertations

Collective magnetic behavior in nanostructures is a phenomenon commonly observed in various magnetic systems. It arises due to competing inter/intra–particle interactions and size distribution and can manifest in phenomena like magnetic freezing, magnetic aging, and exchange bias (EB) effect. In order to probe these rather complex phenomena, conventional DC and AC magnetic measurements have been performed along with radio–frequency transverse susceptibility (TS) measurements. We also demonstrate the magnetic entropy change as a parameter sensitive to subtle changes in the magnetization dynamics of nanostructures. The focus of this dissertation is to study the collective magnetic behavior in core-shell nanostructures of Fe/γ–Fe …

Synthesis Of Titanium Dioxide Photocatalyst With The Aid Of Supercritical Fluids, Haitao Li

USF Tampa Graduate Theses and Dissertations

Titanium Dioxide (TiO2) emerged as one of the most popular photocatalysts since 1970's. However, its photocatalytic activity requires UV irradiation due to its large band gap unless further functionalization or modifications are performed. Furthermore, recovery issue has always been a major drawback, if the more effective form nano particles are utilized.

The key objectives of this research were synthesizing new TiO2 based photocatalyst systems that are effective with both the UV and the visible light while utilizing novel superior environmentally friendly techniques enabling development of nano-structured photocatalysts that can be easily recovered. In this dissertation research, highly porous nano-structured TiO2/WO3/Fe3+ …

Towards Rans Parameterization Of Vertical Mixing By Langmuir Turbulence In Shallow Coastal Shelves, Nityanand Sinha

USF Tampa Graduate Theses and Dissertations

Langmuir turbulence in the upper ocean is generated by the interaction between the wind-driven shear current and the Stokes drift velocity induced by surface gravity waves. In homogenous (neutrally stratified) shallow water, the largest scales of Langmuir turbulence are characterized by full-depth Langmuir circulation (LC). LC consists of parallel counter-rotating vortices aligned roughly in the direction of the wind. In shallow coastal shelves, LC has been observed engulfing the entire water column, interacting with the boundary layer and serving as an important mechanism for sediment re-suspension.

In this research, large-eddy simulations (LES) of Langmuir turbulence with full-depth LC in a …

Improving Implementation Of A Regional In-Line Chlorinator In Rural Panama Through Development Of A Regionally Appropriate Field Guide, Benjamin A. Yoakum

USF Tampa Graduate Theses and Dissertations

Access to safe drinking water has a direct effect on improving human health and their quality of life. One country still struggling with providing access to safe drinking water to all of its population is Panama. Panama's largest indigenous group, the Ngöbe people, is disproportionately affected by lack of access to safe drinking water. One way Panama's Ministry of Health (MINSA) is attempting to increase access to safe drinking water to the Ngöbe people is by disinfecting the water already captured by rural gravity fed water systems constructed within in the Ngöbe-Bugle reservation. This is accomplished using an in-line chlorinator …

Effects Of Partial Confinement And Local Heating On Healing Efficiencies Of Self-Healing Particulate Composites, Jonah Champagne

LSU Master's Theses

Shape memory polymers are smart materials that can be trained to hold a temporary shape through programming and regain their original shape upon heating. Since there discovery in the 1960s, much research has been devoted to the study of these polymers. Of particular interest in recent years is the study of self-healing shape memory polymers. In a previous study, it has been shown that in order for efficient healing to take place in self-healing shape memory polymers, confinement during healing is essential. Moreover, a two-step close-then-heal (CTH) approach to healing was suggested. It was shown that use of this CTH …

A New Versatile Electronic Speckle Pattern Interferometer For Vibration Measurements, Viswanath Bavigadda

Doctoral

Electronic speckle pattern interferometry (ESPI) has been widely used for vibration amplitude and phase measurements. Conventional ESPI systems are bulk and expensive and need careful alignment of all the optical components which is a time consuming task. To overcome these problems alternative compact ESPI systems were developed using fibre-optical components or holographic optical elements (HOEs). The fibre-optic based ESPI systems suffer from random phase fluctuations induced by environmental temperature changes. Hence HOEs can be used as more powerful alternative optical elements to design ESPI systems. The time average ESPI method is widely used for vibration studies. The time average method …

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 …

Nanoscale Electrochemistry By In-Situ Transmission Electron Microscopy, Qi Gao

Dissertations, Master's Theses and Master's Reports - Open

Nanoscale research in energy storage has recently focused on investigating the properties of nanostructures in order to increase energy density, power rate, and capacity. To better understand the intrinsic properties of nanomaterials, a new and advanced in situ system was designed that allows atomic scale observation of materials under external fields. A special holder equipped with a scanning tunneling microscopy (STM) probe inside a transmission electron microscopy (TEM) system was used to perform the in situ studies on mechanical, electrical, and electrochemical properties of nanomaterials. The nanostructures of titanium dioxide (TiO2) nanotubes are characterized by electron imaging, diffraction, and chemical …

Studies Of Functionalized Nanoparticles For Smart Self-Assembly And As Controlled Drug Delivery, Xiaochu Ding

Dissertations, Master's Theses and Master's Reports - Open

This dissertation is related to the studies of functionalized nanoparticles for self-assembly and as controlled drug delivery system. The whole topic is composed of two parts. In the first part, the research was conducted to design and synthesize a new type of ionic peptide-functionalized copolymer conjugates for self-assembly into nanoparticle fibers and 3D scaffolds with the ability of multi-drug loading and governing the release rate of each drug for tissue engineering. The self-assembly study confirmed that such peptide-functionalized amphiphilic copolymers underwent different self-assembly behavior. The bigger nanoparticles were more easily assembled into nanoparticle fibers and 3D scaffolds with larger pore …

Electrophoretic Deposition Of Carbon Nanotubes On Silicon Substrates, Anirban Sarkar

LSU Doctoral Dissertations

This dissertation research describes the feasibility study and investigation of Electrophoretic Deposition (EPD) of carbon nanotubes (CNTs) for applications in semiconductor research. In recent years, the EPD technique has been considered as an economical, room temperature, solution based wet coating technique for thin and thick CNT films on arbitrary substrates. In this study, fabrication of uniform coatings of acid-treated CNTs has been pursued on bare silicon substrates by EPD from aqueous and organic suspensions. Research endeavors are extended to examine EPD of CNTs on silicon substrates with various surface coatings such as metal (aluminum), insulator layers (silicon dioxide and silicon …

Developing Defect-Tolerant Demolding Process In Nanoimprint Lithography, Alborz Amirsadeghi

LSU Doctoral Dissertations

Demolding, the process to separate stamp from molded resist, is most critical to the success of ultraviolet nanoimprint lithography (UV-NIL). In the present study we first investigated adhesion and demolding force in UV-NIL for different compositions of a model UV-curable resist containing a base (either tripropyleneglycol diacrylate with shorter chain length or polypropyleneglycol diacrylate with longer chain length), a cross-linking agent (trimethylolpropane triacrylate) and a photoinitiator (Irgacure 651). The demolding force was measured using a tensile test machine after imprinting the UV resist on a silicon stamp. In general, the shorter monomer shows a larger demolding force. Decreasing the cross-linking …

Size Kinetics And Mechanics Of Clay-Biopolymer Flocs, Hang Yin

LSU Doctoral Dissertations

The suspended cohesive sediments, mostly clay minerals with negative surface charges, usually interact through an array of intermolecular/surface forces (e.g., Coulomb force, van der Waals attractions, and hydrogen bonding) with waterborne organic matter (e.g., exopolymers) and dissolved salts, resulting in fractal, tenuous, and hybrid organic-inorganic flocs or “marine snow”. A pilot and systematic laboratory and theoretical work have been conducted towards a synthetic nanoscale understanding of the flocculation kinetics and mechanics of the clay-exopolymer micro-sized flocs. This systematic study has achieved two impressive objectives: (1) the effect of exopolymer polarity and concentration on the particle size kinetics of clay-exopolymer mixtures …

Designing A Cost Effective Microalgae Harvesting Strategy For Biodiesel Production With Electrocoagulation And Dissolved Air Flotation, Adam James Dassey

LSU Doctoral Dissertations

Microalgal harvesting strategies for biodiesel production have been a major setback in the industry with high energy estimates of $3400/ton biomass by centrifugation. The present study utilized effective mass and energy balances to reduce these large operating costs. The energy for Stage 1 centrifugation was reduced by 82% when harvesting 28.5% of biomass at 18 L/min as opposed to 95% harvesting at 1 L/min. This strategy was further confirmed using electrocoagulation (EC) with Nannochloris and Dunaliella algae with perforated aluminum and iron electrodes at low (< 6 mg/L) metal ion concentrations. Despite 20% lower harvesting efficiencies, the iron electrodes were more energy and cost efficient with operating costs less than $0.03/L oil when flocculating and settling Nannochloris and Dunaliella cultures. Furthermore, a continuous multistage algae harvester using EC and dissolved air flotation (DAF) for Stage 1 harvesting and centrifugation for Stage 2 dewatering was designed. It was determined throughout the testing that greater EC costs for improved harvesting efficiencies were necessary to offset the large energy requirements of the DAF. The multistage system dewatered a low density (100 mg/L) Nannochloris to 20% solids for a final energy requirement of 1.536 kWh/kg algae ($138/ton). Using the data collected from this research and existing literature, a life cycle analysis was assembled to judge the sustainability of microalgal biofuels in Louisiana. High and low energy estimates for culturing (mixing, CO2, nutrients), harvesting, lipid extraction and energy conversion were compared with the current research. Scaling the EC/DAF system for a full size facility was expected to reduce the harvesting costs to 1.133 kWh/kg algae, resulting as $0.44/L oil for a culture with 20% lipids. Despite this improvement in harvesting costs, the production of algal for the sole purpose of biodiesel was not economically viable. Considering a system with a growth rate of 15 g/m2/day and lipid content of 20%, the energy inputs exceeded the outputs from biodiesel production by 36% under the most ideal conditions. However, incorporating additional revenue through wastewater treatment and biogas production from residual biomass could improve sustainability and profitability of algal biodiesel to an 18.5% energy surplus at its current state.

Spider Web Topology: Parameterization And Analysis, Pankaj Rajput, Giovanni Di Ilio, Ronald Diaz

Early Career Technical Journal (ECTJ)

Proceedings of the ASME District F Early Career Technical Conference, November 2-3, 2013. School of Engineering, University of Alabama at Birmingham, Birmingham, Alabama

Section 5: Numerical Methods; pp. 172-179

Design Of A Running Robot And The Effects Of Foot Placement In The Transverse Plane, Timothy James Sullivan

Open Access Theses

The purpose of this thesis is to make advances in the design of humanoid bipedal running robots. We focus on achieving dynamic running locomotion because it is one metric by which we can measure how far robotic technologies have advanced, in relation to existing benchmarks set by humans and other animals. Designing a running human-inspired robot is challenging because human bodies are exceptionally complex mechanisms to mimic. There are only a few humanoid robots designed specifically for running and the existing robots are either constrained to a plane, do not yet exhibit human-like motion, or are unstable.

One aspect of …

Provable Run Time Safety Assurance For A Non-Linear System, Cory Firmin Snyder

Browse all Theses and Dissertations

Systems that are modeled by non-linear continuous-time differential equations with uncertain parameters have proven to be exceptionally difficult to formally verify. The past few decades have produced a number of useful verification tools which can be applied to such systems but each is applicable to only a subset of possible verification scenarios. The Level Sets Toolbox (LST) is one such tool which is directly applicable to non-linear systems, however, it is limited to systems of relatively small continuous state space dimension. Other tools such as PHAVer and the SpaceEx invariant of the Le Guernic-Girard (LGG) support function algorithm are specifically …

The Anisotropic Hyperelastic Biomechanical Response Of The Vocal Ligament And Implications For Frequency Regulation: A Case Study, Jordan E. Kelleher, Thomas Siegmund, Mindy Du, Elhum Naseri, Roger W. Chan

School of Mechanical Engineering Faculty Publications

No abstract provided.

The Case For Interposed Abdominal Compression Cpr In Hospital Settings, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Interposed abdominal compression (IAC)-CPR includes all steps of standard external CPR with the addition of manual mid-abdominal compressions in counterpoint to the rhythm of chest compressions. IAC-CPR can increase blood flow during CPR about two fold compared to standard CPR without IAC, as shown by multiple studies in computer and animal models. The technique increases the rate return of spontaneous circulation (ROSC) for in-hospital resuscitations from roughly 25% to 50%. Improved survival to discharge is demonstrated in two in-hospital trials. IAC as an adjunct technique is quickly taught and is less complex than most other basic life support maneuvers. A …

Induced Damping And Its Relationship To Beneficial Energy Harvesting In Dielectric Elastomers With Application To Walking, Heather L. Lai

Wayne State University Dissertations

This dissertation presents a novel, interdisciplinary research which addresses the potential of applying soft polymeric materials to strategically harvest biomechanical energy in a beneficial manner for use as a viable, low power source for on-board electronics. Of particular interest are electroactive polymers (EAP), which unlike other types of electromechanical smart materials such as piezoelectric ceramics, which are often brittle, have low elastic modulus and can exhibit large strains without substantial stress generations. One type of EAP, the dielectric elastomer (DE), which utilizes electrostatic forces built up across the dielectric polymer to convert between electrical and mechanical energy, is employed in …

Visual Exploration And Information Analytics Of High-Dimensional Medical Images, Darshan Pai

Wayne State University Dissertations

Data visualization has transformed how we analyze increasingly large and complex data sets. Advanced visual tools logically represent data in a way that communicates the most important information inherent within it and culminate the analysis with an insightful conclusion. Automated analysis disciplines - such as data mining, machine learning, and statistics - have traditionally been the most dominant fields for data analysis. It has been complemented with a near-ubiquitous adoption of specialized hardware and software environments that handle the storage, retrieval, and pre- and postprocessing of digital data. The addition of interactive visualization tools allows an active human participant in …