An Investigation On The Band Gap And Band Edge Of Semi-Conducting Lanthanum Transition Metal Perovskites For Photocatalytic Applications,
2015
University of South Florida
An Investigation On The Band Gap And Band Edge Of Semi-Conducting Lanthanum Transition Metal Perovskites For Photocatalytic Applications, Divya Suresh
USF Tampa Graduate Theses and Dissertations
For the past few decades, a frenzy of attention has been given towards the development of an assortment of photocatalysts as a solution for various environmental problems. TiO2 is the most widely used photocatalyst. TiO2 is biocompatible, chemically and thermally stable but TiO2 and a vast majority other photocatalysts have large band gaps, and hence they find applicability only in the UV region of the solar spectrum. These large band gap photocatalysts suffer a severe limitation with regard to their overall process efficiency as the UV region contributes to about 3 to 4 % of the solar spectrum in terms …
Applications Of Optical Properties From Nanomaterials For Enhanced Activity Of A Titania Photocatalyst Under Solar Radiation,
2015
University of South Florida
Applications Of Optical Properties From Nanomaterials For Enhanced Activity Of A Titania Photocatalyst Under Solar Radiation, Jon W. Pickering
USF Tampa Graduate Theses and Dissertations
In recent years, employing advanced oxidation processes (AOPs) as a means of wastewater remediation has emerged as a promising route towards maintaining a sustainable global water management program. The heterogeneous photocatalytic oxidation process has been of particular interest due to the prospective of utilizing solar radiation as the driving force behind the degradation of pollutants. Of the photocatalyst studied to date, TiO2 remains the most attractive material for environmental applications due to its affordability, stability, biocompatibility and high quantum yield. A key draw back however is roughly only 5% of solar radiation incident on earth can provide the energy required …
Topographical Enhancement Of Cell Adhesion On Poorly Adhesive Materials,
2015
University of South Florida
Topographical Enhancement Of Cell Adhesion On Poorly Adhesive Materials, Maritza Muniz Maisonet
USF Tampa Graduate Theses and Dissertations
The overall thrust of this dissertation is to gain a fundamental understanding of the synergistic effects between surface topography and chemical functionality of poorly adhesive materials on enhancing the adhesion of mouse embryonic fibroblasts. Cellular response to surface topography and chemical functionality have been extensively studied on their own providing valuable information that helps in the design of new and improved biomaterials for tissue engineering applications. However, there is a lack of understanding of the synergistic effect of microscale and nanoscale topography with chemical functionality and the relative impact and contribution of each in modulating cellular behavior. By understanding the …
Morphology Of Nanoporous Carbon-Binder Domains In Li-Ion Batteries—A Fib-Sem Study,
2015
Albert Ludwigs Universitat Freiburg
Morphology Of Nanoporous Carbon-Binder Domains In Li-Ion Batteries—A Fib-Sem Study, Severin Vierrath, Lukas Zielke, Riko Moroni, Andrew Mordon, Dean R. Wheeler, Roland Zengerle, Simon Thiele
Faculty Publications
FIB-SEM tomography is used to reconstruct the carbon-binder domain (CBD) of a LiCoO2 battery cathode (3.9 × 5 × 2.3 μm3) with contrast enhancement by ZnO infiltration via atomic layer deposition. We calculate the porosity inside the CBD (57.6%), the cluster-size distribution with a peak at 54 nm, and the pore-size distribution with a peak at 64 nm. The tortuosities of the pore space (1.6–2.0) and the CBD (2.3–3.5) show a mild anisotropy, which is attributed to the fabrication process. A comparison to a modeled homogenous CBD reveals that clustering in the CBD decreases its electronic conductivity while increasing …
The Study Of Plga Drug Delivery Systems: Implications For Management Of Crohn’S Disease,
2015
University of Kentucky
The Study Of Plga Drug Delivery Systems: Implications For Management Of Crohn’S Disease, Christin Pramudiati
Kaleidoscope
The purpose of this research is to develop biodegradable drug delivery systems. One of the delivery systems that we have developed is a suture-like structure for the treatment of Crohn’s disease that utilizes a biodegradable polymer, poly(DL-lactideco-glycolide) acid (PLGA). Crohn’s disease is an inflammatory bowel condition. Aside from the gut involvement, perianal complications develop in the form of enterocutaneous fistulas. Medical management of Crohn’s disease consists of various drugs with immunosuppressive properties. Complicated disease manifestation requires surgical interventions in the form of bowel resection or fistula drainage with Setons. Setons are suture-like devices that help to drain associated abscesses and …
Investigation Of Calcium Orthophosphate Chemical Effects In A Post-Loca Nuclear Reactor Containment,
2015
University of New Mexico
Investigation Of Calcium Orthophosphate Chemical Effects In A Post-Loca Nuclear Reactor Containment, Sterling Olson
Chemical and Biological Engineering ETDs
Calcium leached from NUKON fiberglass in containment following a Loss of Coolant Accident (LOCA) could lead to the formation of chemical precipitates that in turn cause head-loss increase due to filtering through a fibrous debris accumulation at the sump pump screens. Experiments conducted on the bench scale show that the level of fiberglass destruction does not affect the concentration of calcium leached. Reduced-scale experiments were conducted on three solution inventory scales (0.5 L, 31.5 L, 1136 L) with three different flow conditions, and two fiberglass concentrations to investigate calcium release from NUKON fiber. Results showed that the calcium leached at …
An Improved Statistical Analysis For Predicting The Critical Temperature And Critical Density With Gibbs Ensemble Monte Carlo Simulation,
2015
Brigham Young University
An Improved Statistical Analysis For Predicting The Critical Temperature And Critical Density With Gibbs Ensemble Monte Carlo Simulation, Richard A. Messerly, Richard L. Rowley, Thomas A. Knotts Iv, W Vincent Wilding
Faculty Publications
A rigorous statistical analysis is presented for Gibbs ensemble Monte Carlo simulations. This analysis reduces the uncertainty in the critical point estimate when compared with traditional methods found in the literature. Two different improvements are recommended due to the following results. First, the traditional propagation of error approach for estimating the standard deviations used in regression improperly weighs the terms in the objective function due to the inherent interdependence of the vapor and liquid densities. For this reason, an error model is developed to predict the standard deviations. Second, and most importantly, a rigorous algorithm for nonlinear regression is compared …
The Effect Of Surface Modification Of Aligned Poly-L-Lactic Acid Electrospun Fibers On Fiber Degradation And Neurite Extension,
2015
Missouri University of Science and Technology
The Effect Of Surface Modification Of Aligned Poly-L-Lactic Acid Electrospun Fibers On Fiber Degradation And Neurite Extension, Nicholas J. Schaub, Clémentine Le Beux, Jianjun Miao, Robert J. Linhardt, Johan G. Alauzun, Danielle Laurencin, Ryan J. Gilbert
Chemical and Biochemical Engineering Faculty Research & Creative Works
The surface of aligned, electro spun poly-L-lactic acid (PLLA) fibers was chemically modified to determine if surface chemistry and hydrophilicity could improve neurite extension from chick dorsal root ganglia. Specifically, diethylenetriamine (DTA, for amine functionalization), 2-(2-aminoethoxy) ethanol (AEO, for alcohol functionalization), or GRGDS (cell adhesion peptide) were covalently attached to the surface of electro spun fibers. Water contact angle measurements revealed that surface modification of electro spun fibers significantly improved fiber hydrophilicity compared to unmodified fibers (p < 0.05). Scanning electron microscopy (SEM) of fibers revealed that surface modification changed fiber topography modestly, with DTA modified fibers displaying the roughest surface structure. Degradation of chemically modified fibers revealed no change in fiber diameter in any group over a period of seven days. Unexpectedly, neurites from chick DRG were longest on fibers without surface modification (1651 ± 488 μm) and fibers containing GRGDS (1560 ± 107 μm). Fibers modified with oxygen plasma (1240 ± 143 μm) or DTA (1118 ± 82 μm) produced shorter neurites than the GRGDS or unmodified fibers but were not statistically shorter than unmodified and GRGDS modified fibers. Fibers modified with AEO (844 ± 151 μm) were significantly shorter than unmodified and GRGDS modified fibers (p< 0.05). Based on these results, we conclude that fiber hydrophilic enhancement alone on electro spun PLLA fibers does not enhance neurite outgrowth. Further work must be conducted to better understand why neurite extension was not improved on more hydrophilic fibers, but the results presented here do not recommend hydrophilic surface modification for the purpose of improving neurite extension unless a bioactive ligand is used.
A Numerical Comparison Of Precipitating Turbulent Flows Between Large-Eddy Simulation And One-Dimensional Turbulence,
2015
University of Utah
A Numerical Comparison Of Precipitating Turbulent Flows Between Large-Eddy Simulation And One-Dimensional Turbulence, Alex W. Abboud, Ben B. Schroeder, Tony Saad, Sean T. Smith, Derek D. Harris, David O. Lignell
Faculty Publications
This study presents the results of computational fluid dynamics simulations of a multiphase, reacting, turbulent mixing layer in an idealized geometry. The purpose is to compare large-eddy simulation (LES) to one-dimensional turbulence (ODT) and examine the trends of the flow under differing mixing conditions. Aqueous streams are mixed together to precipitate polymorphs of calcium carbonate. The polymorphs of calcium carbonate are tracked numerically using population balance equations (PBE). Each PBE contains all of the relevant physical models to track the particle evolution including nucleation, growth, and aggregation. A simple subgrid mixing model that is convenient for use with PBEs was …
Local Time-Averaged Gas Holdup In Fluidized Bed Reactor Using Gamma Ray Computed Tomography Technique (Ct),
2015
Missouri University of Science and Technology
Local Time-Averaged Gas Holdup In Fluidized Bed Reactor Using Gamma Ray Computed Tomography Technique (Ct), Abdelsalam Efhaima, Muthanna H. Al-Dahhan
Chemical and Biochemical Engineering Faculty Research & Creative Works
Many Invasive and Non-Invasive Techniques Have Been Used to Analyze the Hydrodynamics of Fluidized Beds. in This Study, the Effect of Superficial Gas Velocity and Bed Particle Density on the Hydrodynamics of Gas–solid Fluidized Beds Was Investigated by using a Cylindrical Plexiglas Fluidized Bed Column, 14 Cm in Diameter. Air at Room Temperature Was Used as the Fluidizing Gas and Two Different Geldart Type-B Particles Were Used: Glass Beads and Copper Particles with Material Densities of 2.5 and 5.3 G/cm3, Respectively, with the Same Size Particle, 210 µm. to Measure the Time-Averaged Cross-Sectional Gas and Solid Holdup Distribution, Gamma Ray …
An Improved Dynamic Particle Packing Model For Prediction Of The Microstructure In Porous Electrodes,
2015
Brigham Young University - Provo
An Improved Dynamic Particle Packing Model For Prediction Of The Microstructure In Porous Electrodes, Chien-Wei Chao
Theses and Dissertations
The goal of this work is to develop a model to predict the microstructure of Li-ion batteries, specifically focusing on the cathode component of the batteries. This kind of model has the potential to assist researchers and battery manufacturers who are trying to optimize the capacity, cycle life, and safety of batteries. Two dynamic particle packing (DPP) microstructure models were developed in this work. The first is the DPP1 model, which simulates the final or dried electrode structure by moving spherical particles under periodic boundaries using Newton's laws of motion. The experience derived from developing DPP1 model was beneficial in …
The Role Of Biological Fluid And Dynamic Flow In The Behavior And Cellular Interactions Of Gold Nanoparticles,
2015
University of Dayton
The Role Of Biological Fluid And Dynamic Flow In The Behavior And Cellular Interactions Of Gold Nanoparticles, Emily K. Breitner, Saber M. Hussain, Kristen K. Comfort
Chemical and Materials Engineering Faculty Publications
Background: Due to their distinctive physicochemical properties, nanoparticles (NPs) have proven to be extremely advantageous for product and application development, but are also capable of inducing detrimental outcomes in biological systems. Standard in vitro methodologies are currently the primary means for evaluating NP safety, as vast quantities of particles exist that require appraisal. However, cell-based models are plagued by the fact that they are not representative of complex physiological systems. The need for a more accurate exposure model is highlighted by the fact that NP behavior and subsequent bioresponses are highly dependent upon their surroundings. Therefore, standard in vitro models …
Characterization Of Iron Phthalocyanine As The Cathode Active Material For Lithium-Ion Batteries,
2015
University of Dayton
Characterization Of Iron Phthalocyanine As The Cathode Active Material For Lithium-Ion Batteries, Sarwan S. Sandhu, Joseph P. Fellner
Chemical and Materials Engineering Faculty Publications
The developed thermodynamic functions for the determination of Gibbs free energy, enthalpy, and entropy of formation of solid lithium-iron phthalocyanine (LixFePc) from solid lithium and iron phthalocyanine as a function of x, defined as g-moles of the intercalated lithium per g-mole of iron phthalocyanine, at a fixed set of temperature and pressure conditions are presented. In addition, a proposed expression for the evaluation of lithium diffusion coefficient in solid iron phthalocyanine as a function of both x and temperature, and the experimental results from the ongoing research/development work on the lithium/iron phthalocyanine cells are included.
Hydrodynamics, Dissolution, And Mass Transfer Effects In Different Dissolution Testing Apparatuses And Laboratory Systems,
2015
New Jersey Institute of Technology
Hydrodynamics, Dissolution, And Mass Transfer Effects In Different Dissolution Testing Apparatuses And Laboratory Systems, Bing Wang
Dissertations
Dissolution testing apparatuses and shaker flasks agitated by shaker tables are laboratory systems routinely found in many laboratories at most companies and agencies, and especially in pharmaceutical companies. These devices are commonly used in a number of applications, from drug development to quality control. Despite their common use, these systems have not been fully investigated from an engineering perspective in order to understand their operation characteristics. For example, the hydrodynamics of many of these systems have received little attention until relatively recently, and only over the last few years have some of these systems, such as the USP dissolution testing …
Magnetic Ngf-Releasing Plla/Iron Oxide Nanoparticles Direct Extending Neurites And Preferentially Guide Neurites Along Aligned Electrospun Microfibers,
2015
Missouri University of Science and Technology
Magnetic Ngf-Releasing Plla/Iron Oxide Nanoparticles Direct Extending Neurites And Preferentially Guide Neurites Along Aligned Electrospun Microfibers, Jonathan M. Zuidema, Christina Provenza, Tyler Caliendo, Silvio Dutz, Ryan J. Gilbert
Chemical and Biochemical Engineering Faculty Research & Creative Works
Nerve growth factor releasing composite nanoparticles (NGF-cNPs) were developed to direct the extension of neurite outgrowth from dorsal root ganglia (DRG). Iron oxide magnetic nanoparticles were incorporated into poly-l-lactic acid (PLLA) nanoparticles in order to position the NGF-cNPs in a culture dish. Neurites growing from DRG extended toward the NGF released from the NGF-cNPs. DRG were then cultured on aligned PLLA microfibers in the presence of NGF-cNPs, and these biomaterials combined to align DRG neurite extension along one axis and preferentially toward the NGF-cNPs. This combinatorial biomaterial approach shows promise as a strategy to direct the extension of regenerating neurites.
Synthesis, Structure And Electrochemical Performance Of Na2Mnsio4/C Cathode Material For Na-Ion Batteries,
2015
State Key Lab of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;
Synthesis, Structure And Electrochemical Performance Of Na2Mnsio4/C Cathode Material For Na-Ion Batteries, Shou-Ding Li, Jiang-Huai Guo, Yong Xie, Jin-Xiao Mi, Yong Yang
Journal of Electrochemistry
As a promising cathode material for sodium ion batteries, pure phase Na2MnSiO4/C nanocomposite was successfully synthesized by a sol-gel method with a citric acid as a complex agent. The as prepared material was characterized by XRD, FTIR, SEM and TEM techniques. XRD and Rietveld refinement results indicated that the sample was indexed as monoclinic structure with space group of Pn. It was observed by SEM and TEM that the obtained product consisted of micro-scaled secondary particles, which were composed of NaMnSiO4 nanocrystallites and amorphous carbon network. More importantly, the uniform carbon network in the …
Preparation And Characterization Of Carbon Supported Pd-Sb Composite Nanocatalysts For Formic Acid Electrooxidation,
2015
Key Laboratory of Shanghai Colleges and Universities for Corrosion Control in Electric Power System and Applied Electrochemistry, Shanghai University of Electric Power, Shanghai 200090, China;
Preparation And Characterization Of Carbon Supported Pd-Sb Composite Nanocatalysts For Formic Acid Electrooxidation, Long-Long Wang, Xiao-Lu Cao, Ya-Jun Wang, Jin-Hao Ping, Qiao-Xia Li
Journal of Electrochemistry
Palladium is considered as an efficient anode catalyst with high catalytic activity for electrooxidation of formic acid. To further improve the catalytic activity and stability, alloying or surface modification with Sb is an effective way. In this work, the well dispersed carbon supported Pd-Sb composite nanocatalysts (Pd-Sb/C) were synthesized by traditional impregnation reduction method with trisodium citrate as the complexing agent, sodium borohydride as the reducing agent. The morphologies of Pd-Sb/C and the effects of molar ratio of Pd to Sb on the electrocatalytic properties of Pd-Sb/C for HCOOH electrooxidation were studied. The XRD and XPS analyses on the as-prepared …
Effect Of Adsorption Potential On Co Oxidation At Au@Pt Nanoparticles Electrodes, A Surface Enhanced Raman Spectroscopic Study,
2015
Hefei National Laboratory for Physical Science at Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China;
Effect Of Adsorption Potential On Co Oxidation At Au@Pt Nanoparticles Electrodes, A Surface Enhanced Raman Spectroscopic Study, Pu Zhang, Yi Wei, Yong-Li Zheng, Yan-Xia Chen, Zhong-Qun Tian
Journal of Electrochemistry
The adsorption/oxidation of CO on the 55 nm [email protected] nm Pt nanoparticles electrode in both potentiodynamic and potentiostatic modes were investigated by surface enhanced Raman spectroscopy in a thin layer electrochemical flow cell under controlled mass transport, with the aim of clarifying the origin CO oxidation at lower electrode potentials (in current pre-wave region of corresponding cyclic voltammograms). Our results demonstrated that the CO oxidation kinetics differed significantly from the three kinds of different CO adsorption history, with almost no CO oxidation current in the pre-peak potential region after 0.35 VRHE CO adsorption with or without subsequent holding the …
Synthesis And Electrochemical Performance Of Mn3O4/Graphene Composites,
2015
State Key Lab of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;
Synthesis And Electrochemical Performance Of Mn3O4/Graphene Composites, Shan-Shan Yang, Qian Zhang, Xiong-Gui Lin, Ming-Sen Zheng, Quan-Feng Dong
Journal of Electrochemistry
The Mn3O4/Graphene composites were synthesized by hydrothermal method with the in-situ redox reaction of graphene oxide (GO) and manganese acetate (Mn(Ac)2). The phase structures and morphologies of the materials were characterized by XRD, SEM and TEM. The XPS and IR techniques were used for studying the residual function groups of reduced graphene oxide (RGO). The electrochemical performances of the hybrids were tested in a coin cell. Results showed that the composites prepared with the addition of ammonia water (RM-A) have better performance. The graphenes in RM-A were better-reduced and the Mn3O4 …
Tungsten Carbide/Carbon Electrode Material Synthesized By Block Copolymer Template Method,
2015
State Key Laboratory Breeding Base for Green Chemistry Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310032, China;College of Chemical and Materials Science, Longyan University, Longyan 364000, Fujian, China;
Tungsten Carbide/Carbon Electrode Material Synthesized By Block Copolymer Template Method, Xiao-Ling Lang, Ye-Kun Jiang, Mei-Qin Shi, Ling-Zhi Kang, Chun-An Ma
Journal of Electrochemistry
At present, one of the major hurdles for commercialization of system with direct methanol fuel cell (DMFC) is still the requirement of a significant amount of platinum (Pt) catalyst to achieve an acceptable power density. Pt and Pt-based metals are expensive due to limited supplies. In order to find the catalyst alternative to the Pt metal, we selected tungsten carbide (WC) and its composites as the study object. We synthesized WC with carbon materials as the suitable support to modify the electronic structure and to increase the specific surface area of WC. In this study, tungsten carbide/carbon (WC/C) was prepared …
