Digital Commons Network^™

Geophysical Mapping Of Preferential Flow Paths Across Multiple Floodplains, Ronald B. Miller, Derek M. Heeren, Garey A. Fox, Daniel E. Storm, Todd Halihan, Aaron R. Mittelstet

Department of Agricultural and Biological Systems Engineering: Faculty Publications

In the Ozark ecoregion of Oklahoma, Arkansas and Missouri, the erosion of carbonate bedrock (primarily limestone) by slightly acidic water has left a residuum of chert gravel, producing gravel-bed streams and floodplains generally consisting of coarse chert gravel overlain by a mantle (1 to 300 cm) of gravelly loam or silt loam. Previous research has documented the occurrence of preferential flow paths (PFP) in an alluvial floodplain hypothesized to be a buried gravel bar. Field experiments have shown that the PFP affected alluvial groundwater flow in the floodplain and that water flow in the PFP was transmitted at rates that …

Antenna Development For Radio Frequency Hyperthermia Applications, Sergio Curto

Doctoral

This thesis deals with the design steps, development and validation of an applicator for radio frequency hyperthermia cancer therapy. An applicator design to enhance targeted energy coupling is a key enabler for preferential temperature increments in tumour regions. A single-element, near-field approach requires a miniaturised solution, that addresses ergonomic needs and is tolerant to patient anatomy. The antenna war-field rriodality and the high-dielectric patient loading introduce significant analytical and computational resource challenges. The antenna input impedance has to be sufficiently insensitive to in-band resonant cletuning and the fields in the tissue can he targeted to selected areas in the patient. …

Effect Of Simulated Visual Impairment On Nighttime Driving Performance, Joanne Wood, Alex Chaparro, Trent Carberry, Byoung Sun Chu

Publications

Purpose. This study investigated the effects of simulated visual impairment on nighttime driving performance and pedestrian recognition under real-road conditions.

Methods. Closed road nighttime driving performance was measured for 20 young visually normal participants (M = 27.5 +- 6.1 years) under three visual conditions: normal vision, simulated cataracts, and refractive blur that were incorporated in modified goggles. The visual acuity levels for the cataract and blur conditions were matched for each participant. Driving measures included sign recognition, avoidance of low contrast road hazards, time to complete the course, and lane keeping. Pedestrian recognition was measured for pedestrians wearing either black …

Epidermal Neural Crest Stem Cell (Epi-Ncsc)--Mediated Recovery Of Sensory Function In A Mouse Model Of Spinal Cord Injury, Yao Fei Hu, Krishnaj Gourab, Clive Wells, Oliver Clives, Brian D. Schmit, Maya Sieber-Blum

Biomedical Engineering Faculty Research and Publications

Here we show that epidermal neural crest stem cell (EPI-NCSC) transplants in the contused spinal cord caused a 24% improvement in sensory connectivity and a substantial recovery of touch perception. Furthermore we present a novel method for the ex vivo expansion of EPI-NCSC into millions of stem cells that takes advantage of the migratory ability of neural crest stem cells and is based on a new culture medium and the use of microcarriers. Functional improvement was shown by two independent methods, spinal somatosensory evoked potentials (SpSEP) and the Semmes-Weinstein touch test. Subsets of transplanted cells differentiated into myelinating oligodendrocytes. Unilateral …

Cell-Mediated Elastic Matrix Regeneration Toward Regression Of Abdominal Aortic Aneurysms, Carmen Gacchina

All Dissertations

Abdominal aortic aneurysms (AAAs) are typically fusiform (symmetric) dilations of the aortic wall most commonly arising below the renal arteries. The progression is typically associated with an activated smooth muscle cell (SMC) phenotype, diminished density of mature medial elastic fibers, and an elevated presence of matrix-degrading enzymes (e.g., matrix-metalloproteases; MMPs), which may ultimately lead to vessel rupture. Currently, no surgical or non-surgical methods are available to regress AAAs via regeneration of new elastin matrices to regain normal vessel contour, particularly due to the inherently poor elastin synthesis by adult vascular cells and absence of methods to stimulate the same. Previously, …

Synthesis Of Pegylated Single Wall Carbon Nanotubes By A Photoinitiated Graft From Polymerization, Pu Zhang, David B. Henthorn

Chemical and Biochemical Engineering Faculty Research & Creative Works

A considerable amount of research has been devoted to carbon nanotubes because of their unique electrical, mechanical, optical, and chemical properties. Here, in this report, we introduce a novel, simple ultraviolet initiated "graft from" polymerization method to synthesize PEGylated carbon nanotubes. This grafting procedure significantly enhanced nanotube aqueous dispersibility and long-term stability in solution. Mass of grafted polymer chains was easily modulated by adjusting polymerization reaction time, and nanomaterials containing up to 80% polymer by weight were synthesized. Nanotube morphology was characterized by SEM, TEM before and after the functionalization. in addition, the covalent bonding of polymer chains to the …

Novel Micron- And Nano-Scale Energetic Materials For Advanced Gun Propulsion, Their Material Properties, And Their Effects On Ballistic Performance, Thelma Gatuz Manning

Dissertations

This dissertation focused on the investigation of novel materials that are both energetic and inert in their micron- and nano-scale crystalline form. The characterization of the materials properties and its effects on the ballistic performance when incorporated into a composite material were evaluated as a gun propellant for application in a future weapon system for the US Army. Some of these materials may find dual use in civilian applications. Applications in small and medium arms, artillery, tank, aircraft, and shipboard gun systems will all benefit from these advancements. Not only will gun system performance be improved for greater stand-off range …

Constitutive Modeling Of Glassy Memory Polymers, Mahesh Khanolkar

Dissertations

The aim of this research is to develop constitutive models for non-linear materials. Here, issues related for developing constitutive model for glassy shape memory polymers are addressed in detail. Shape memory polymers are novel material that can be easily formed into complex shapes, retaining memory of their original shape even after undergoing large deformations. The temporary shape is stable and return to the original shape is triggered by a suitable mechanism such heating the polymer above a transition temperature. Glassy shape memory polymers are called glassy because the temporary shape is fixed by the formation of a glassy solid, while …

Design Of Drug Delivery Strategies Based On Well-Stirred Experiments, Kumud Kanneganti

Theses

Drugs are generally administered to the human body via injections (IV) or through other paths such as the buccal, nasal routes. The main consideration when designing a medication schedule is to maintain a therapeutic level of the drug in the body during the course of treatment. To achieve this goal, when IV drug therapy is selected, particular importance has to given to the dose to be injected and how to maintain the concentration of the pharmaceutical active ingredient (API) in the body between a Minimum Toxic Concentration (MTC) and a Minimum Effective Concentration (MEC). This therapeutic range varies with the …

Minimum Agitation Speed For Solid Suspension And Mixing Time In A Torispherical -Bottomed Pharmaceutical Stirred Tank Under Different Baffling Conditions, Dilanji Bhagya Wijayasekara

Theses

The minimum agitation speed, NS, required to just suspend solid particles dispersed in water was experimentally determined in this work for a glass-lined type of mixing tank provided with a torispherical bottom and agitated with a retreat-blade impeller under different baffling configurations. Ns for the same tank but equipped with a different agitation system, namely an axial impeller, was also experimentally determined for the purpose of comparing of performances of the two systems. The effect of impeller off- bottom clearance and the vessel's liquid level on the minimum agitation speed were also experimentally studied. Njs, was experimentally determined …

Axon Guided Axon Growth In Drg Neurons From The Spinal Cord Of Rat Embryos, Neha Jain

Theses

Early studies in the area of neuronal physiology and injury have shown that axons are guided by a number of physical as well as chemical cues. Although the guidance effect of initial axons and their processes on later axons has been shown from a development point of view, little light has been thrown on the subject from the injury point of view. This important ability of axons which plays a key role during development and formation of neuronal networks could become crucial in repairing damaged nerves and disrupted neuronal tracts.

In the following study, the guidance effect of an older …

Comparison Between Different Techniques Of Preprocessing For Resting State Fmri Analysis, Megha Girdhar

Theses

Resting state functional connectivity as the name suggests is defined as significant temporal correlation between spatially distinct regions of the brain during rest. In this thesis, fMRI resting state dataset was analyzed using different available processing techniques with the same fMRI data to study differences between the various methods. All the imaging data from each of the subjects was processed in an identical fashion. The same method was used for detecting connectivity. The number of independent components in the data was used as the base to differentiate the effect of each of these methods. Independent component analysis was performed on …

Effects Of Monoclonal Anti-Abeta Antibodies On The Amyloid Beta Peptide Fibrillogenesis And Their Involvement In The Clearance Of Alzheimer's Disease Plaques, Jeffy Pilar Jimenez

USF Tampa Graduate Theses and Dissertations

Alzheimer’s disease (AD) is the most common cause of senile dementia worldwide. AD is a neurodegenerative disorder characterized by the loss of memory and language skill, collapse of the cognitive function, and distortion of social behavior. As of today, the onset mechanisms of AD and cure are unknown; however, three hallmarks are commonly encountered: extra and intracellular accumulation of amyloid beta (A!) peptide plaques, formation of intracellular neurofibrillary tangles, and inevitable neuronal death. Hypothetically, a possible scenario provoking or involved in the onset of AD is a cascade effect that starts with an imbalance in the production and clearance of …

Ecotourism And Water Quality: Linking Management, Activities And Sustainability Indicators In The Caribbean, Ken Darrie Thomas

USF Tampa Graduate Theses and Dissertations

Ecotourism from its genesis and founding theories has been set out to conserve and preserve the environment through sustainable operation that includes surrounding communities in efforts to reduce their poverty levels. Over the years ecotourism has been hypothesized to have departed from this ideal with several researchers, through social, qualitative analyses, have said that these non-sustainable ecotourism operations are simply due to poor management. This work sought to test this central hypothesis as a first approach to quantitatively linking ecotourism activities to management with surface water quality as the key indicator of sustainable ecotourism as a complex system through systems …

Application Of Structured Light Imaging For High Resolution Mapping Of Underwater Archaeological Sites, Chris Roman, Gabrielle Inglis, James Rutter

Graduate School of Oceanography Faculty Publications

This paper presents results from recent work using structured light laser profile imaging to create high resolution bathymetric maps of underwater archaeological sites. Documenting the texture and structure of submerged sites is a difficult task and many applicable acoustic and photographic mapping techniques have recently emerged. This effort was completed to evaluate laser profile imaging in comparison to stereo imaging and high frequency multibeam mapping. A ROV mounted camera and inclined 532 nm sheet laser were used to create profiles of the bottom that were then merged into maps using platform navigation data. These initial results show very promising resolution …

The Effect Of Step Load Moving On The Surface Of A Cylindrical Cavity Using Neural Networks, Hamed Saeidi, Mansour Nikkhah-Bahrami

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Potential functions and Fourier series method in the cylindrical coordinate system are employed to solve the problem of moving loads on the surface of a cylindrical bore in an infinite elastic and isotropic medium. The steady state dynamic equations of medium are uncoupled by applying potential functions. The medium responses are obtained by using an appropriate numerical method of Laplace transform inversion. The solution has an integral form; therefore, a feedforward backpropagation neural network is designed and trained using the response evaluated numerically in a finite set of random points to approximate stress and displacement components in the medium. It …

Artificial Neural Network Model For Prediction Of Liquefaction Potential In Soil Deposits, F. Farrokhzad, A. J. Choobbasti, A. Barari

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

With the increase in population, the evaluation of liquefaction is becoming more important for land use planning and development. In soil deposits under undrained condition, earthquakes induce cyclic shear stresses, may lead to soil liquefaction. Artificial neural network (ANN) is one of the, artificial intelligence (AI) approaches that can be classified as machine learning. Simplified methods have been practiced by researchers to assess nonlinear liquefaction potential of soil. In order to address the collective knowledge built up in conventional liquefaction engineering, an alternative general regression neural network model is proposed in this paper. To meet this objective, a total of …

Estimating Seismic Parameters Associated With Previous Earthquakes By Scptu Soundings In The Nmsz, Tianfei Liao, Paul W. Mayne

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Although the New Madrid seismic zone (NMSZ) is the most active seismic region in the eastern United States, paleoliquefaction features are often used to analyze the previous seismic activities, due to the long recurrence interval of large earthquakes. A new methodology is proposed in this paper to estimate the seismic parameters associated with previous earthquakes based on the results of seismic cone penetration tests (SCPT), using the simplified procedure of liquefaction analysis and the attenuation relationships developed for the corresponding seismic areas. This methodology is validated through the paleoliquefaction studies at two sites associated with the 1989 Loma Prieta earthquake …

Rainwater Harvesting And Greywater Treatment Systems For Domestic Application In Ireland, Zhe Li, Fergal Boyle, Anthony Reynolds

Articles

Water shortage has been recognised as one of the key issues facing many countries. Fortunately, there are relatively abundant water resources available in Ireland because of its plenty of rainfall. However, Ireland will inevitably encounter water shortage in the future, especially in urban areas. The water consumption per capita per day in Ireland is one of the highest in Europe. The water demand is still increasing due to population growth and higher standard of living. The use of domestic rainwater harvesting and greywater treatment systems has the potential to supply nearly 94% of domestic water in Irish households. The utilisation …

Social Networking: A Boon To Criminals, Tejashree D. Datar, Richard Mislan

Annual ADFSL Conference on Digital Forensics, Security and Law

With the world getting more and more digitized, social networking has also found a place in the cyber world. These social networking sites (SNSs) which enable people to socialize, and build and maintain relationships are attracting attention of all kinds of people such as teens, adults, sports persons, and even businesses. But these SNSs are also getting unwanted attention from people like sexual predators, spammers, and people involved in criminal and illegal activities. This paper talks about SNSs and how these sites are exploited for criminal or illegal activity. The SNSs are discussed in detail with respect to user profiles, …

Numerical Investigation Of Gas Sampling From Fluidized Beds, John Grace, Tingwen Li, Yongmin Zhang, Xiaotao Bi

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

Gas mixing in a tall narrow fluidized bed operated in the slugging fluidization regime is studied with the aid of computational fluid dynamics. Three-dimensional numerical simulations are performed with an Eulerian-Eulerian model. Predicted axial and radial tracer concentration profiles for various operating conditions are generally in good agreement with experimental data from the literature. Different field variables including voidage, tracer concentration, and gas velocity at upstream and downstream levels are analysed to study gas mixing. Mean tracer concentrations in the dense phase and the bubble phase are evaluated and significant differences between them are found. The time-mean concentration is weighted …

Investigation Of The Effect Of Fluidization Time On Electrostatic Charge Generation In Gas-Solid Fluidized Beds, Amanda Giffin, Andrew Sowinski, Poupak Mehrani

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

This work focused on determining the effect of the fluidization time on particle charging. Charge equilibrium was reached on the bed particles after 60 minutes. The wall particle layer was built with negative and positive charges. Similar sized particles migrated to each region of the bed regardless of fluidization time.

Electricity Generation Characteristics Of An Anaerobic Fluidized Bed Microbial Fuel Cell, Qingjie Guo, Shuju Zhao, Xuyun Wang, Xuehai Yue, Liangyu Hou

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

Anaerobic fluidized bed microbial fuel cell (AFBMFC) was developed to investigate the effect of fluidization behaviors on the electrogenesis capacity. Waste water and active carbon were used as liquid and solid phase, respectively. The fuel cell was started up successfully using anaerobic activated sludge as inoculums. The power density is increased with increasing circular liquid velocity up to 450 mW·m-2. High COD remove rate reached 93% after five days operation. Meanwhile, the effects of cathode area on the electrogenesis capacity of AFB MFC were also investigated.

Hydrodynamic Characteristics Of Liquid-Solid Fluidization Of Binary Mixtures In Tapered Beds, Sankarshana Talapuru Dr, J S N Murthy, S Nandana, Phani Kiran S V G R, V Ramesh

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

The problems associated with fluidization in cylindrical beds like entrainment of particles, limitation of operating velocity could be overcome by adopting tapered beds. There have been no systematic studies reported on fluidization behavior of binary mixtures wherein the effect of size ratio is considered on the hydrodynamic characteristics of liquid-solid fluidization in tapered beds. In the present work, an attempt has been made to study the fluidization behavior and hydrodynamic characteristics of liquid-solid fluidization of binary mixtures of size ratios ranging from 1.2 to 5.13 using sand of different sizes in tapered beds of apex angles 50, 100 and 150. …

A Study On Denitrification In A Fluidized Bed Bioreactor, L. Prasanna Lakshmi, Y. Pydi Setty, K. Vimala

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

The work involves experimental investigation on biological denitrification in a fluidized bed reactor under anaerobic conditions using the microorganism Pseudomonas Stutzeri and plastic beads as fluidizing medium. The influence of various parameters like pH, initial nitrate concentration, Carbon/Nitrogen ratio, hydraulic retention time on nitrate-nitrogen removal rate from synthetic effluent prepared at the laboratory were studied in detail. The optimum operating conditions of pH, initial nitrate concentration, Carbon/Nitrogen ratio and flow rate obtained are 7.0–7.5, 15 mg/l, 1.5–2.0 and 4.41 x 10-5 m3/s respectively.

Development Of A Continuous Nanoparticle Coating With Electrospraying, N. Ellis, J. Ruud Van Ommen, C.U. Yurteri

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

Coating of micron-sized particles (host particles) with nanoparticles can result in modifying the surface properties of host particles leading to various applications. This work presents a novel concept of combining the electrospraying of nanoparticles onto the charged particles entrained out of the fluidized bed for developing a continuous coating process. By controlling the processes to effectively charge and contact particles using electric forces, we are able to fine-tune the properties of the obtained nano-coated particles.

Effect Of Distributor Design On Solids Circulation And Gas Bypass In An Internal Circulating Fluidized Bed Reactor, Xiaotao T. Bi, Terris T. Yang

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

The effect of the distributor design on the gas bypass and solids circulation was investigated for the flat, cylindrical and conical gas distributors in a cold model internal circulating fluidized bed to provide design and operating criteria for the future application of ICFB deNOx reactor. A high gas bypass ratio from the annulus to draft tube and low from the draft tube to annulus were identified for all tested distributors. The solids circulation rates increased with the increase of both annulus and draft tube gas velocities, where the conical distributor exhibited a more flexible and stable operation. The particle size …

Experiments And Modelling Of Micro-Jet Assisted Fluidization Of Nanoparticles, J. Ruud Van Ommen, David M. King, Alan Weimer, Robert Pfeffer, Berend Van Wachem

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

The fluidization of nanoparticle agglomerates can be largely improved by using downward pointing micronozzles, creating a high-velocity jet, as experimentally shown. By discrete particle simulations – treating the agglomerates as single particles – we show that the main reason is probably the reduction of the agglomerate size by agglomerate-agglomerate collisions.

Investigation Of Change Of Volumetric Flow In Fluidized-Bed Reactors, Andrés Mahecha-Botero, Franz Haseidl, Alexander Nguyen, Tingwen Li, John R. Grace

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

Volumetric flow can change due to such factors as variation in the number of moles due to reaction, feed distribution, change of phase, membranes and changes in temperature and pressure. This change in volumetric flow was investigated by varying the fluidized-bed pressure in a two-dimensional steel column. Pressure was impulsively adjusted, showing large transient voids during the transitions after rapid growth of the existing bubbles. The effects of sudden depressurization as well as elevated pressure fluidization were also investigated.

Numerical And Experimental Steady State Flow And Heat Transfer In A Continuous Spouted Bed, Cezar A. Rosa, José T. Freire, Hamid Arastoopour

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

Experimental measurements on heat transfer and flow properties and CFD simulations based on the two-fluid model (Eulerian-Eulerian approach) were performed in a draft tube continuous spouted bed system. The simulated results on the gas-particle flow patterns and the temperature distribution in the bed agreed well with our experimental data.