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Direct Simulations Of Cells Motions And Deformations In Flow, Quan Jin

Dissertations

Direct numerical simulations (DNS) are used to study the motions and deformations of blood cells, especially leukocytes, in pressure driven flows in parallel plate channels with both smooth and uneven walls under adhesion force between the leukocytes and the channel wall.

Leukocytes are represented by two composite fluid models. The first model is the compound-drop model in which the cytoplasm and the nucleus are modeled as fluids, and the second one is the drop-rigid-particle model in which the cytoplasm is modeled as a fluid and the nucleus as a rigid particle. The adhesion force is computed using two adhesion force …

Formation Of Rdx Nanoparticles By Rapid Expansion Of Supercritical Solution : In Situ Characterization By Laser Scattering, Takuya Matsunaga

Dissertations

Cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX), a well-known energetic material, is highly explosive. Reduction of the sensitivity of RDX is desired for safe handling and

storage in military applications. Data on the sensitivity of RDX in the 10-1000 µm crystal size range suggested that the impact sensitivity could be further reduced by reduction of the crystal size to the sub-micron or nano-scale (Armstrong, 1990). Recent research with nano-RDX obtained using Rapid Expansion of Supercritical Solutions (RESS) confirmed these expectations (Stepanov, 2005).

RESS process appeared to be one out of a few techniques of production of nanoscale energetic materials free of the risk of explosion. …

Central And Peripheral Autonomic Influences : Analysis Of Cardio-Pulmonary Dynamics Using Novel Wavelet Statistical Methods, Anne Marie Petrock

Dissertations

The development and implementation of novel signal processing techniques, particularly with regard to applications in the clinical environment, is critical to bringing computer-aided diagnoses of disease to reality. One of the most confounding factors in the field of cardiac autonomic response (CAR) research is the influence of the coupling of respiratory oscillations with cardiac oscillations.

This research had three objectives. The first was the assessment of central autonomic influence over heart rate oscillations when the pulmonary system is damaged. The second was to assess the link between peripheral and central autonomic control schema by evaluating the heart rate variability (HRV) …

In Vitro Studies Of Degradation And Bioactivity Of Aliphatic Polyesther Composites, Georgia Chouzouri

Dissertations

In spite of numerous publications on the potential use of combinations of aliphatic polyester composites containing bioactive fillers for bone regeneration, little information exists on the combined in vitro mechanisms involving simultaneously diffusion for polymer degradation and bioactivity through nucleation and growth of apatite in simulated body fluid (SBF) solution. The objective of this study is to contribute to the understanding of the fundamentals in designing non-porous, solid materials for bone regeneration, from experimental data along with their engineering interpretation.

Bioactivity, in terms of apatite growth, was assessed through several experimental methods such as scanning electron microscopy (SEM), energy dispersive …

In Vitro Feasibility Testing Of Floating Light-Activated Minroelectrical Stimulators, Ammar Riad Abdo

Theses

One of the major challenges of neural stimulation is the mechanical stress and resulting trauma induced on the implanted electrodes by the constant movement of the interconnects. A potential way of eliminating interconnects is to use floating micro-stimulators that can be activated through optical means. As a method of energy transfer to the micro-stimulator, we propose to use a laser beam at near infrared (NIR) wavelengths.

There are two main objectives in this project to test the feasibility of the main approach; investigate the charge injection capacity of titanium nitride (TiN) and iridium oxide (IrOx) as potential contact materials, and …

Mechanisms Causing Ferric Staining In The Secondary Water System Of Brigham City, Utah, Robert Derring Wallace

Theses and Dissertations

Water from Mantua reservoir has, during some years, exhibited reddish-brown staining when used by Brigham City for irrigation. I propose that seasonal fluctuations in the reservoir chemistry create an environment conducive to dissolving iron from the iron-rich sediments, which subsequently precipitate during irrigation, resulting in a staining event. These conditions are produced by chemical and biological decomposition of organic matter, coupled with isolation of the hypolimnetic waters, which results in seasonal low concentrations of dissolved oxygen in these waters. Under these specific circumstances, anaerobic conditions develop creating a geochemical environment that causes iron and manganese reduction from Fe(III) to Fe(II) …

Pt-Ru Nanoparticles Supported On Carbon Nanotubes As Methanol Fuel Cell Catalysts, Liang Li, Yangchuan Xing

Chemical and Biochemical Engineering Faculty Research & Creative Works

Bimetallic Pt - Ru alloy catalysts have been demonstrated to be more active than pure Pt catalysts in the electrooxidation of methanol. We report here a study on Pt - Ru nanoparticle catalysts supported on sonochemically functionalized carbon nanotubes. the catalysts were prepared by directly reducing the corresponding salts, K2PtCl4 and K 2RuCl5, in an ethylene glycol aqueous solution containing dispersed carbon nanotubes. Three catalysts of different Pt to Ru atomic ratios, namely, Pt53Ru47, Pt69Ru31, and Pt77Ru23, were prepared for investigation of the compositional effects, It was shown that highly dispersed bimetallic Pt - Ru alloy nanoparticles with no agglomeration …

Ucf Recommissioning Project Final Report, Florida Solar Energy Center, James Cummings

FSEC Energy Research Center®

A research project was carried out to examine the energy savings which occurred from recommissioning three University of Central Florida buildings. Recommissioning activities completed in two of the three buildings yielded chilled water and whole building electricity savings on the order of 15% to 30%. Recommissioning implementation is pending in the third building, where savings are projected to be in the range of 40% to 50% of total building energy use. Additionally, cooling energy savings were monitored (and calculated) for a green roof installation at one of these three buildings. Calculated savings were found to be 1.05 kWh/day for a …

Pharmacokinetics Of Ultrasonically-Released, Micelle-Encapsulated Doxorubicin In The Rat Model And Its Effect On Tumor Growth, Bryant J. Staples

Theses and Dissertations

Chemotherapy is one of the most successful cancer treatments used today. Unfortunately, the amount of chemotherapy a patient can receive is limited by the associated negative side effects, such as cardiotoxicity, immune system suppression, and nephrotoxicity. Encapsulation of these drugs, Doxorubicin (DOX) in particular, in stabilized Pluronic micelles (Plurogel TM) shows success in limiting these harmful side effects. In previous studies, low-frequency ultrasound (US) has been shown, in vitro, to locally release DOX from these micelles. In this study, a novel drug delivery system involving the encapsulation of DOX in Plurogel and the release of the drug at the tumor …

Characteristics Of Manure Harvested From Beef Cattle Feedlots, William F. Kissinger, Richard K. Koelsch, Galen E. Erickson, Terry J. Klopfenstein

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Open lot cattle production systems present unique challenges for nutrient planning processes. Previous estimates of quantities and characteristics of harvested manure from this type of facility are based upon data from the early 1970s. In addition, harvested manure is impacted by weather, feeding program, season, and pen management decisions. The objectives of this study are to characterize under commercial conditions for open lot beef systems: 1) harvested manure quantities and characteristics; 2) impact of factors such as feeding program, season, and management on harvested manure; and 3) mass balance for nitrogen (N) and phosphorus (P). Data from six commercial feedlots …

Radial Distribution Of Local Concentration Weighted Particle Velocities In High Density Circulating Fluidized Beds, Gorkem Kirbas, Sung Won Kim, Xiaotao Bi, Jim Lim, John R. Grace

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

An extensive experimental investigation of radial profiles of concentration -weighted particle velocities was carried out by simultaneously measuring local transient particle velocity, solids concentration and solids flux using a three-fibre optical probe at five axial levels and seven radial locations in a 0.2 m diameter riser operating over a wide range of solids circulation fluxes (198 to 350 kg/m 2s) and superficial gas velocities (6 to 8 m/s). Particle velocities averaged over time and concentration-weighted particle velocities were compared and found to differ from each other, the latter being smaller than the former at most radial locations. The difference, which …

Effect Of Particle Size Distribution On The Performance Of A Catalytic Fluidized Bed Reactor, Sanjib Das Sharma, Todd S. Pugsley

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

Computational Fluid Dynamics (CFD) has been used to model ozone decomposition in a two-dimensional fluidized bed of 2.0 meters height and 0.1 m width. Simulations were carried out with mono-size, bimodal, and wide catalyst particle size distributions with the same mean diameter to model the effect of fines on the reaction. CFD predictions fall within 20% of the experimental data.

Treatment Of Voc Emissions In A Gas-Solid Fluidized Bioreactor, Kyla Clarke, Gordon A. Hill, Todd S. Pugsley

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

A fluidized bioreactor, with a bed of moist sawdust and glass spheres, successfully treated ethanol-contaminated air. The maximum elimination capacity was 75 g m-3sawdust h-1 for the fluidized bed compared to 225 g m-3sawdust h-1 for a packed bed (essentially a biofilter).

Fluidized Bed Polymer Particle Ald Process For Producing Hdpe/Alumina Nanocomposites, Joseph A. Spencer, Xinhua Liang, Steven M. George, Karen J. Buechler, John Blackson, Charles J. Wood, John R. Dorgan, Alan W. Weimer

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

Micron-sized High Density Polyethylene (HDPE) particles were coated with ultrathin alumina (Al2O3) films in a Fluidized Bed Reactor (FBR) by Atomic Layer Deposition (ALD) at 77 ºC. Al2O3 films on the HDPE particles were confirmed by different methods. These particles were extruded conventionally with the ceramic shells mixing intimately in the polymer matrix. The successful dispersion of the Al2O3 shells in the polymer matrix following extrusion was confirmed using cross sectional Transmission Electron Microscopy (TEM).

Modeling Of An Interconnected Fluidized Bed Reactor For Chemical Looping Combustion, Min Xu, Naoko Ellis, Ho-Jung Ryu , C. Jim Lim

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

Chemical Looping Combustion (CLC) is comprised of two reactors, in which direct contact between air and fuel is avoided. A metal oxide, as oxygen carrier, transports oxygen from the air reactor to the fuel reactor while circulating between them. Based on the hydrodynamics coupled with reaction kinetics of oxygen carrier from the literature, a model for an interconnected fluidized bed reactor has been developed to optimize the design and operation of the reactor system. The model considers the chemical reaction of a single particle and a particle population balance for the calculation of bed particle conversion. The core-annulus and two-phase …

Cold Modelling Of An Internally Circulating Fluidized Bed Membrane Reactor, Tony Boyd, John R. Grace, C. Jim Lim, A. M. Adris

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

A novel fluidized bed membrane reactor with internal catalyst circulation is being developed for the production of high-purity H2 from an autothermal reformer. In order to provide guidance to pilot reactor testing, a cold model was built to study the influence of reactor configuration on hydrodynamics and catalyst circulation. It was found that catalyst circulation was reproducible, but that parallel non-communicating flow channels could lead to flow instability. Solids circulation was found to be adequate for design of the autothermal reformer.

Thermal Conversion Of Biomass And Waste, Liban Yassin, Paola Lettieri, Stefaan Simons, Antonino Germanà

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

This paper investigates the process designs of 2 fluidized bed gasification plants utilizing clean biomass. Energy and mass balances for each process were carried out and ChemCAD was used to evaluate the energy recovery process by simulating the operation of a steam turbine and a combined cycle gas turbine (CCGT).

Hydrodynamic And Rtd Of Sectionalized Bubble Column, Nahidh W. Mecaial, Burhan Sadik

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

The sectionalization of conventional bubble columns to tray partitioned bubble column using perforated trays has been used to investigate the effect of tray hole diameter, tray open area, superficial gas velocity, gas sparger design, and liquid phase properties on gas holdup, residence time distribution (RTD), and overall liquid-phase backmixing. The erected column is sectionalized into three stages using two perforated plates of different holes diameter and open free area. Overall gas holdup is measured experimentally by bed expansion technique. Liquid backmixing, mixing time and axial dispersion model (ADM) is determined using tracer response experiments. In general, it seems that the …

Role Of Intrinsic Kinetics And Catalyst Particle Size Distribution In Cfd Simulations Of Polymerization Reactors, Rong Fan, Rodney O. Fox, Michael E. Muhle

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

Fluidized-bed reactors are widely used in the production of polyethylene. In this work, the quadrature method of moments (QMOM), a chemical reaction engineering (CRE) model, and computational fluid dynamics (CFD) are combined to investigate the role of intrinsic kinetics and the catalyst particle size distribution (PSD) in a gas phase fluidized bed reactor. The catalyst PSD is represented by a few nodes using the QMOM and an intrinsic rate model based on the age of particles is used to solve the evolution of particle temperature, particle size, and catalyst sites with age. Assuming the particle age distribution is well-mixed, the …

Volume Contraction In Liquid Fluidization Of Binary Solids Mixtures, Norman Epstein , R. Escudié, John R. Grace, Xiaotao T. Bi

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

When liquid-fluidized particles of radically different sizes and densities mix, the serial (additive volume) model fails to predict the fluidized bed voidage due to contraction of the mixed bed relative to the volumetric sum of the corresponding monocomponent beds. Models are proposed to predict contraction reported in the literature for both upflow and downflow fluidization.

Monitoring Electrostatic Charges In Fluidized Beds, Xiaotao T. Bi, Aihua Chen, John R. Grace

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

A novel analysis procedure for dynamic collision probes has been developed to monitor the charge density of particles in gas-solids fluidized beds based on the mean and normalized standard deviation of current signals. The contribution from hydrodynamic changes is decoupled from the changes in specific particle charge density based on the principles that the average current is related to charge transfer and/or triboelectrification due to the contact between the probe and particles, whereas the normalized standard deviation of current signals is mainly related to the hydrodynamic changes of the fluidized bed. The correlation between hydrodynamic changes and current signal fluctuations …

Microfluidic Velocity Measurements Using Three-Dimensional Confocal Micro Particle Tracking Velocimetry (Cm-Ptv), Orin Hemminger, Zhao Yu, Chunhe Zhang, L. James Lee, L .S. Fan

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

In the past, confocal microscopy was limited by its slow temporal resolution and was not a practical tool for imaging dynamic systems. Recent improvements in spinning disk confocal microscopy and high-speed camera technology have made it a viable technique for imaging of microfluidic systems. Here, a confocal micro particle tracking velocimetry (CM-PTV) system is demonstrated with the ability to obtain 3D velocity profiles at high flow rates.

Scale-Up Effect On Heat Transfer In A Fluidized Bed Near The Onset Of Turbulent Fluidization, A. Stefanova, John R. Grace, C. Jim Lim, Xiaotao T. Bi, K.S. Lim, J. Sanderson

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

Heat transfer coefficients were measured in 0.29 m ID and 1.56 m ID fluidization columns with the same heater tube, identical alumina particles and geometrically scaled distributors. The maximum coefficients occurred in the turbulent fluidization flow regime. The Froude number based on superficial velocity and column diameter captures the scale-up effect well, so long as the heater is located in a region of similar flow structure.

Time Scale Analysis Of A Fluidized-Bed Catalytic Reactor Based On A Generalized Dynamic Model, Andres Mahecha-Botero, John R. Grace, Said S.E.H. Elnashaie, C. Jim Lim

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

A fluidized-bed reactor model is implemented to simulate a Maleic Anhydride (MA) reactor with special emphasis on its dynamic behaviour. The dynamic model is general enough that it can treat a wide range of catalytic systems, subject to mass and energy balances within the phases. The model represents multiple phases and regions (low-density phase, high-density phase, freeboard region) and can account for heat and mass axial and radial anisotropic dispersion, change in molar/volumetric flow due to reaction, temperature and pressure profiles, hydrodynamic regime variation, catalyst deactivation, energy options, and multiple membranes of various geometries for introduction/extraction of any compound. The …

Title Page - Table Of Contents - Preface - List Of Reviewers, Xiaotao T. Bi, Franco Berruti, Todd S. Pugsley

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

No abstract provided.

Improved Standpipe Entrance For Stable High-Flux Flow, D. Rusnell, John R. Grace, Xiaotao T. Bi, C. Jim Lim, P. Ronan, C. A. Mcknight

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

Cold model tests were used to show the causes of instabilities in the operation of the standpipe entrance (“sore thumb”) in industrial scale fluid cokers. New geometries were tested which might provide higher flows and prevent operating problems such as flow reversals and flooding, while also minimizing the adverse effects of fouling. The tests were conducted using FCC particles in a geometrically and dynamically scaled half-column of approximately 1/9th scale which had previously been used to show the effects of baffles on fluid coker strippers. The addition of sloping surfaces to increase the surface area for ingress of particles was …

Presentation Slides: Analytical Multi-Scale Methodology For Fluidization Systems - Retrospect And Prospect, Jinghai Li

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

No abstract provided.

Flow Characteristics Of Fully Wetted Binary Solid Mixtures In Gas Fluidized Beds With Inclined Gas Distributors, Yusumi Nagahashi, John R. Grace, Norman Epstein, Yutaka Asako, Akira Yokogawa

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

A unique gas-fluidized bed in which fluidization is enhanced by adding a little water has potential for soft abrasive washing of various products. Preliminary experiments were carried out for the washing of farm products. Gas fluidized beds of binary solids mixtures with inclined gas distributors provide hydrodynamic and mixing data assisting the design of dry and wet gas-fluidized beds.

Gas-Solid Structure In The Vicinity Of A Sparger Nozzle In A Fluidized Bed, Pierre Sauriol, Heping Cui, Jamal Chaouki

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

An experimental approach is proposed to investigate the gas-solid structure in the vicinity of a sparger nozzle in a fluidized bed. The local hydrodynamics were studied under injection velocities ranging between 0 and 100 m/s and three orientations. A fiber-optic probe was used to measure the instantaneous local particle holdup near the tip of the sparger nozzle. Under the investigated conditions, the local gas-solid structure was influenced on the measurement position, nozzle orientation and injection velocity. Four distinct zones were identified from the local particle holdup data, with the boundaries corresponding to characteristic jet lengths. Strong discrepancies were found with …

The Differential Effects Of Two Critical Osteoclastogenesis Stimulating Factors On Bone Biomechanics, Yuyu Yuan

All Dissertations

Many skeletal diseases, such as osteoporosis and malignant bone metastases, are generally osteolytic and associated with increased bone resorption and decreased bone strength. Within a complex cytokine environment, the proteins RANKL and M-CSF are critical for osteoclast differentiation and activation, and thus fundamental effectors of osteolytic disorders. Previous studies showed that M-CSF stimulates the proliferation and early differentiation of osteoclast progenitors to osteoclast lineage, while RANKL targets the later stages of fusion and activation, and stimulates the formation of functional active osteoclasts. However, impacts of artificially elevated levels of these proteins on the skeleton system have not been fully characterized. …