Engineering Commons^™

Novel Magnetic Nanostructures For Enhanced Magnetic Hyperthermia Cancer Therapy, Zohreh Nemati Porshokouh

USF Tampa Graduate Theses and Dissertations

In this dissertation, I present the results of a systematic study on novel multifunctional nanostructure systems for magnetic hyperthermia applications. All the samples have been synthesized, structurally/magnetically characterized, and tested for magnetic hyperthermia treatment at the Functional Materials Laboratory of the University South Florida. This work includes studies on four different systems: (i) Core/shell Fe/γ-Fe₂O₃ nanoparticles; (ii) Spherical and cubic exchange coupled FeO/Fe₃O₄ nanoparticles; (iii) Fe₃O₄ nano-octopods with different sizes; (iv) High aspect ratio FeCo nanowires and Fe₃O₄ nanorods.

In particular, we demonstrated the enhancement of the heating …

Creation And Evaluation Of Polymer/Multiwall Carbon Nanotube Films For Structural Vibration Control And Strain Sensing Properties, Weiwei Lin

FIU Electronic Theses and Dissertations

Multifunctional materials both with damping properties and strain sensing properties are very important. They promise to be more weight-efficient, and provide volume-efficient performance, flexibility and potentially, less maintenance than traditional multi-component brass-board systems.

The goal of this dissertation work was to design, synthesize, investigate and apply polyaniline/Multiwall carbon nanotube (PANI/MWCNT) and polyurethane (PU) /MWCNT composites films for structural vibration control and strain sensors using free layer damping methods and static and dynamic strain sensing test methods.

The PANI/MWCNT was made by in situ polymerization of PANI in the presence of MWCNT, then frit compression was used to make circular and …

Molybdenum Disulfide-Conducting Polymer Composite Structures For Electrochemical Biosensor Applications, Hongxiang Jia

USF Tampa Graduate Theses and Dissertations

Lactic acid is widely existing in human bodies, animals and microorganisms. Recently, using biosensor to detect the concentration of lactic acid and diagnose disease have attracted great research and development interests. Nanocomposites is one of the best material used for biosensor because their wonderful conductivity, optical and electrochemical properties. In the study, MoS₂ and polypyrrole (PPY) are used for the composite material electrode. To determine whether lactate oxidase (LOD) was helpful for the biosensor’s detective properties, both PPY-MoS₂ film with LOD and PPY-MoS₂ film without LOD are being tested. The fourier transform infrared spectroscopy (FTIR) and Raman …

Video Capture And Post-Processing Technique For Approximating 3d Projectile Trajectory, Chase M. Pfeifer, Judith M. Burnfield, Guilherme M. Cesar, Max H. Twedt, Jeff A. Hawks

Department of Mechanical and Materials Engineering: Faculty Publications

In this paper we introduce a low-cost procedure and methodology for markerless projectile tracking in three-dimensional (3D) space. Understanding the 3D trajectory of an object in flight can often be essential in examining variables relating to launch and landing conditions. Many systems exist to track the 3D motion of projectiles but are often constrained by space or the type of object the system can recognize (Qualisys, Göteborg, Sweden; Vicon, Oxford, United Kingdom; Opti-Track, Corvallis, Oregon USA; Motion Analysis, Santa Rosa, California USA; Flight Scope, Orlando, Florida USA). These technologies can also be quite expensive, often costing hundreds of thousand dollars. …

Exploring Public Values Implications Of The I-Corps Program, Jan Youtie, Philip Shapira

Philip Shapira

The Study Of Dynamical Electrochemical Impedance Spectroscopy For Oxygen Reduction Reaction On Pt/C Catalyst, Kun-Ming Shi, Jian-Wei Guo, Jia Wang

Journal of Electrochemistry

With joint techniques of rotating disc electrode(RDE) and electrochemical impedance spectroscopy(EIS), and further establishment on equivalent circuit model, this paper studied oxygen reduction reaction(ORR) on commercial Pt/C catalyst in acid medium. Our results found that the dynamical interface on Pt/C consists of two independent processes: 1) the PtO reduction from Pt surface, 2) the new PtO formation from ORR, thus providing key clues for catalyst stability and activity. This also implied that the dynamical interface facilitates reconstruction for porous electrode, and matches with mass transfer. One important issue is discovered that at high overpotential, the high reaction rate for ORR …

Template-Assisted Hydrothermal Synthesis Of Nio@Co3O4 Hollow Spheres With Hierarchical Porous Surfaces For Supercapacitor Applications, Wen Zhou, Xue-Feng Lu, Ming-Mei Wu, Gao-Ren Li

Journal of Electrochemistry

Hollow structures have shown great potentials in a variety of important applications, such as energy conversion and storage. In order to further enhance the performance, the rational design of hollow structures with higher complexity in terms of composition and structure is highly desirable and still remains a great challenge. In this work, an efficient strategy was established for the fabrication of novel NiO@Co₃O₄ hollow spheres (HSs) with hierarchical porous surfaces by silica spheres template-assisted hydrothermal synthesis. The as-fabricated NiO@Co₃O₄ HSs showed high specific surface area of 219.68 m²·g^-1, and significant …

Construction And Sodium Storage Performance Of Complex One-Dimensional Nanomaterials, Yuan-Jie Zhang, Wei Li, Xuan-Peng Wang, Chao-Jiang Niu, Li-Qiang Mai

Journal of Electrochemistry

Abstract: One-dimensional nanomaterials have been widely studied in energy storage and conversion fields because of their unique structure and physicochemical properties. Sodium-ion batteries are highly promising and attractive for large-scale energy storage due to the truly abundant sodium resources and low cost. With the growing demand of energy and deepening of research, the evolution of structures and properties of one-dimensional nanomaterials are also experiencing from simplicity to complexity and from ordinary to excellence. Therefore, constructing complex superior one-dimensional nanomaterials has become one of the hotspot in energy storage. Based on the new advance in this field and Mai group’s work, …

Micro/Nano-Structured Electrode Materials For Sodium-Ion Batteries, Shuang Yuan, Yun-Hai Zhu, Sai Wang, Tao Sun, Xin-Bo Zhang, Qiang Wang

Journal of Electrochemistry

Sodium has similar physics and chemical properties to lithium, alternatively, sodium (Na)-ion batteries have again aroused a great deal of interest recently, particularly for large-scale stationary energy storage applications due to the practically infinite sodium resources and low cost. However, the technics and materials for Na-ion batteries are immature. Therefore, development of advanced anode and cathode materials for Na-ion batteries is urgently desired but remains a great challenge. This paper briefly reviews some recent progresses in this field, addressing the morphology effects, as well as functions of carbon composite materials toward Na-ion batteries. Several electrode materials with micro/nano-structures based on …

Evolution From The Plasmon To Exciton State In Ligand-Protected Atomically Precise Gold Nanoparticles, Meng Zhou, Chenjie Zeng, Yuxiang Chen, Shuo Zhao, Matthew Y. Sfeir, Manzhou Zhu, Rongchao Jin

Publications and Research

The evolution from the metallic (or plasmonic) to molecular state in metal nanoparticles constitutes a central question in nanoscience research because of its importance in revealing the origin of metallic bonding and offering fundamental insights into the birth of surface plasmon resonance. Previous research has not been able to probe the transition due to the unavailability of atomically precise nanoparticles in the 1-3 nm size regime. Herein, we investigate the transition by performing ultrafast spectroscopic studies on atomically precise thiolate-protected Au₂₅, Au₃₈, Au₁₄₄, Au₃₃₃, Au_∼520 and Au_∼940 nanoparticles. Our results …

Effects Of Fiber Aspect Radio On Mechanical Performances Of Nano-Short-Fiber-Reinforced Rubber Composites, Zhu Dasheng

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.

Influence Of Imperfections On Carbon Nanotube Properties, Marino Brcic, Marko Canadija, Josip Brnic

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.

Mechanical Properties Of Stainless Steels With Heterogeneous Nanostructures, Hiromi Miura, Masakazu Kobayashi, Natuko Sugiura, Naoki Yoshinaga

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.

Wetting And Interfacial Microstructure Of Porous Si3n4/Si3n4 Joint After Silver Metallization, Yanli Zhuang, Tiesong Lin, Shengjin Wang, Peng He, Dusan P. Sekulic, Dechang Jia, Hongmei Wei

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.

Review On Joining Of Advanced Materials And Dissimilar Materials In Harbin Institute Of Technology, Jun Qu, Yongping Lei, Peng He, Yunlong Chang

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.

Numerical Simulation Of Heat Transfer In Porous Metals For Cooling Applications, Edgar Avalos Gauna, Yuyuan Zhao

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.

Analysis Of Corrosion-Induced Diffusion Layer In Zk60a Magnesium Alloy.Pdf, Shumin Li

Shumin Li

Applied Photoproperties Of Phenylene Ethynylenes, Patrick L. Donabedian

Nanoscience and Microsystems ETDs

Light-absorbing molecules can be used as powerful tools to perturb and understand biological systems by fluorescence, sensitization, or photochemical reactions. A thorough understanding of the delivery of dyes to specific biochemical targets and the processes that control the fate of excited-state energy is needed to engineer useful technology out of organic photochemistry. This thesis presents four projects investigating different aspects of pathogen destruction and biochemical sensing in a variety of systems, using the properties of p-phenylene ethynylenes (PEs), an especially flexible and well-studied class of conjugated molecules. Of particular relevance, some PEs are found to be effective dyes for amyloid …

Modelling And Simulation Of The Flexoelectric Effect On A Cantilevered Piezoelectric Nanoplate, Xining Wang

Electronic Thesis and Dissertation Repository

Piezoelectric nanomaterials have attracted increasing attentions due to their distinct electromechanical features, especially the size-dependent properties, which differ greatly from their bulk counterparts.

Due to the large strain gradients presented in nanostructures, the flexoelectricity is believed to be responsible for such size-dependent properties. In this thesis, based on the Kirchhoff plate model and the extended linear piezoelectric theory, a modified continuum mechanics based model is developed to study the size-dependent flexoelectric effect upon the static bending behaviors of a cantilevered piezoelectric nanoplate (PNP). Finite difference method (DFM) is employed to obtain the approximate numerical solutions.

The numerical results indicate that …

Fabrication And Characterization Of Conductive Melt Electrospun Fibers, Brandon Ross

Graduate Theses & Non-Theses

Conductive polymer nanocomposites are a type of particle reinforced plastic composite where the doping material is electrically conductive. The diverse properties of an engineered composite material allow for the material properties to be fine-tuned for the specific application. This research focuses on using carbon allotropes, such as two-dimensional graphene and one-dimensional carbon nanotubes, to achieve direct current electrical conductivity through a polymer fiber. Melt electrospinning is the process used for creating the micrometer scale fibers by melting thermoplastic materials. High electrostatic fields apply a force to the polymer melt and a single fiber is drawn out. The resistivity of the …

Potential Applications For Halloysite Nanotubes Based Drug Delivery Systems, Lin Sun

Doctoral Dissertations

Drug delivery refers to approaches, formulations, technologies, and systems for transporting a drug in the body. The purpose is to enhance the drug efficacy and to reduce side reactions, which can significantly improve treatment outcomes. Halloysite is a naturally occurred alumino-silicate clay with a tubular structure. It is a biocompatible material with a big surface area which can be used for attachment of targeted molecules. Besides, loaded molecules can present a sustained release manner in solution. These properties make halloysite nanotubes (HNTs) a good option for drug delivery.

In this study, a drug delivery system was built based on halloysite …

Generalized Partial Directed Coherence And Centrality Measures In Brain Networks For Epileptogenic Focus Localization, Joshua Aaron Adkinson

Doctoral Dissertations

Accurate epileptogenic focus localization is required prior to surgical resection of brain tissue for treatment of patients with intractable temporal lobe epilepsy, a clinical need that is partially fulfilled to date through a subjective, and at times inconclusive, evaluation of the recorded electroencephalogram (EEG). Using brain connectivity analysis, patterns of causal interactions between brain regions were derived from multichannel EEG of 127 seizures in nine patients with focal, temporal lobe epilepsy (TLE). The statistically significant directed interactions in the reconstructed brain networks were estimated from three second intracranial multi-electrode EEG segments using the Generalized Partial Directed Coherence (GPDC) and validated …

Metal-Organic Hybrid Nanocomposites For Energy Harvesting Applications, Thulitha Madawa Abeywickrama

Masters Theses & Specialist Projects

Various synthetic methods have been developed to produce metal nanostructures including copper and iron nanostructures. Modification of nanoparticle surface to enhance their characteristic properties through surface functionalization with organic ligands ranging from small molecules to polymeric materials including organic semiconducting polymers is a key interest in nanoscience. However, most of the synthetic methods developed in the past depend widely on non-aqueous solvents, toxic reducing agents, and high temperature and high-pressure conditions. Therefore, to produce metal nanostructures and their nanocomposites with a simpler and greener method is indeed necessary and desirable for their nano-scale applications. Hence the objective of this thesis …

Lab-On-A-Chip Nucleic-Acid Analysis Towards Point-Of-Care Applications, Varun Lingaiah Kopparthy

Doctoral Dissertations

Recent infectious disease outbreaks, such as Ebola in 2013, highlight the need for fast and accurate diagnostic tools to combat the global spread of the disease. Detection and identification of the disease-causing viruses and bacteria at the genetic level is required for accurate diagnosis of the disease. Nucleic acid analysis systems have shown promise in identifying diseases such as HIV, anthrax, and Ebola in the past. Conventional nucleic acid analysis systems are still time consuming, and are not suitable for point-ofcare applications. Miniaturized nucleic acid systems has shown great promise for rapid analysis, but they have not been commercialized due …

Thermal Analysis Of Continuous And Patterned Multilayer Films In The Presence Of A Nanoscale Hot Spot, Jia-Yang Juang, Jinglin Zheng

Department of Mechanical and Materials Engineering: Faculty Publications

Thermal responses of multilayer films play essential roles in state-of-the-art electronic systems, such as photo/micro-electronic devices, data storage systems, and silicon-on-insulator transistors. In this paper, we focus on the thermal aspects of multilayer films in the presence of a nanoscale hot spot induced by near field laser heating. The problem is set up in the scenario of heat assisted magnetic recording (HAMR), the next-generation technology to overcome the data storage density limit imposed by superparamagnetism. We characterized thermal responses of both continuous and patterned multilayer media films using transient thermal modeling. We observed that material configurations, in particular, the thermal …

An Examination Of The Indentation Size Effect In Fcc Metals And Alloys From A Kinetics Based Perspective Using Nanoindentation, David Earl Stegall

Mechanical & Aerospace Engineering Theses & Dissertations

The indentation size effect (ISE) in metals is described as the rise in hardness with decreasing depth of indentation and contradicts conventional plasticity behavior. The goal of this dissertation is to further examine the fundamental dislocation mechanisms that may be contributing to the so-called indentation size effect. In this work, we examined several metals and alloys including 99.999% Aluminum (SFE ~200 mJ/m²), 99.95% Nickel (SFE ~125 mJ/m²), 99.95% Silver (SFE ~22 mJ/m²⁾, and three alloys, alpha brass 70/30 (SFE >10 mJ/m²), 70/30 nickel copper (SFE ~100 mJ/ …

Case Study Of Quantifying Energy Loss Through Ceiling-Attic Recessed Lighting Fixtures Through 3d Numerical Simulation, Ri Na, Shengmao Lin, Zhigang Shen, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

Abstract Air leakage through recessed lighting fixtures has been identified as a common issue that causes extra energy consumption in residential buildings. However, few quantitative studies in this area were found. As such, a preliminary assessment of the magnitude of this type of energy loss was conducted by using three-dimensional (3D) transient computational fluid dynamics (CFD) models. A hypothetical layout of recessed lighting fixtures was designed with boundary conditions of four different seasons, which were obtained from recorded roof/attic temperature data sets. The results of the study indicate that leakage of recessed lighting fixtures could be a significant channel of …

Compositionally Graded Bulk Heterojunction Devices And Methods Of Manufacturing The Same, Jinsong Huang, Zhengguo Xiao

Department of Mechanical and Materials Engineering: Faculty Publications

Systems and methods are described to form compositionally graded BHJ structures utilizing solvent-fluxing techniques. In implementations, the systems and methods described herein involve a high boiling point additive, a solution of a polymer donor and an acceptor, a substrate material, a working solvent, and a flux solvent for formation of compositionally graded BHJ structures.

Development Of Novel Nanomaterials For Lithium Sulfur Batteries, Xia Li

Electronic Thesis and Dissertation Repository

Lithium-sulfur batteries are considered as the most promising next generation high-energy batteries. Compared with other kinds of battery, Li-S batteries have ultra-high theoretical energy density, which is a good candidate for electric vehicles and hybrid electric vehicles in future. However, there are still many challenges to be addressed in Li-S batteries. Design of electrodes, selection of electrolytes, and battery assemble have direct effects on the safety, cost and electrochemical performance of Li-S batteries. Therefore, it is greatly important to develop novel electrodes to achieve high-energy for Li-S batteries. This thesis mainly focuses on the design of sulfur cathode of Li-S …

Hydraulic And Electrokinetic Delivery Of Remediants For In-Situ Remediation, Ahmed I. A. Chowdhury

Electronic Thesis and Dissertation Repository

Nano-scale zero valent iron (nZVI) has shown promising mobility and in-situ reactivity with chlorinated volatile organic compounds when injected into saturated porous media. The current study evaluated nZVI mobility and subsequent reactivity with in-situ contaminants in a variably saturated porous media. The nZVI particles, synthesized onsite at subzero temperatures, demonstrated complete trichloroethene (TCE) degradation within the target area. Furthermore, a three dimensional finite difference model (CompSim) was utilized to investigate nZVI mobility in variably saturated zones. Model predicted well head data were in very good agreement with field observations. Simulation results showed that the injected slurry migrated radially outward from …