Engineering Commons^™

Confinement Effects And Magnetic Interactions In Magnetic Nanostructures, Kristen Lee Stojak Repa

USF Tampa Graduate Theses and Dissertations

Multifunctional nanocomposites are promising for a variety of applications ranging from microwave devices to biomedicine. High demand exists for magnetically tunable nanocomposite materials. My thesis focuses on synthesis and characterization of novel nanomaterials such as polymer nanocomposites (PNCs) and multi-walled carbon nanotubes (MWCNTs) with magnetic nanoparticle (NP) fillers.

Magnetite (Fe₃O₄) and cobalt ferrite (CoFe2O4) NPs with controlled shape, size, and crystallinity were successfully synthesized and used as PNC fillers in a commercial polymer provided by the Rogers Corporation and poly(vinylidene fluoride). Magnetic and microwave experiments were conducted under frequencies of 1-6 GHz in the presence of …

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 …

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 …

Electrospinning Of Polymeric Solutions Using Opuntia Ficus-Indica Mucilage And Iron Oxide For Nanofiber Membranes For Treating Arsenic Contaminated Water, Venkatesh Eppili

USF Tampa Graduate Theses and Dissertations

Water is the essential part of every organism and it is also a vital constituent of healthy living and diet. Unfortunately water contamination over the past decade has increased dramatically leading to various diseases. As technology advances, we are detecting many pollutants at smaller levels of concentrations. Arsenic (As) is one of those major pollutants, and Arsenic poisoning is a condition caused due to excess levels of arsenic in the body. The main basis for Arsenic poisoning is from ground water which naturally contains high concentrations of arsenic. A case study from 2007 states that over 137 million people in …

Preparation And Characterization Of Van Der Waals Heterostructures, Horacio Coy Diaz

USF Tampa Graduate Theses and Dissertations

In this dissertation different van der Waals heterostructures such as graphene-MoS₂ and MoTe₂-MoS₂ were prepared and characterized. In the first heterostructure, polycrystalline graphene was synthesized by chemical vapor deposition and transferred on top of MoS₂ single crystal. In the second heterostructure, MoTe₂ monolayers were deposited on MoS₂ by molecular beam epitaxy.

Characterization of graphene-MoS₂ heterostructures was conducted by spin and angle resolve spectroscopy which showed that the electronic structure of the bulk MoS₂ and graphene in this van der Waals heterostructures is modified. For MoS₂ underneath the graphene, a band …

Al/Ti Nanostructured Multilayers: From Mechanical, Tribological, To Corrosion Properties, Sina Izadi

USF Tampa Graduate Theses and Dissertations

Nanostructured metallic multilayers (NMMs) are well-known for their high strength in smaller bilayer thicknesses. Six Al/Ti (NMM) with different individual layer thickness were tested for their mechanical hardness using a nanoindentation tool. Individual layer thicknesses were chosen carefully to cover the whole confined layer slip (CLS) model. Nano-hardness had a reverse relation with the square root of individual layer thickness and reached a steady state at ~ 5 nm bilayer thickness. Decreasing the layer bilayer thickness from ~ 104 nm to ~ 5 nm, improved the mechanical hardness up to ~ 101%. Residual stresses were measured using grazing incident X-ray …

The Change In Nutritional Status In Traumatic Brain Injury Patients: A Retrospective Descriptive A Retrospective Descriptive Study, Dina A. Masha'al

USF Tampa Graduate Theses and Dissertations

There is a high prevalence in malnutrition among traumatic brain injury (TBI) due to the hypermetabolism and hypercatabolism which develop post injury. Traumatic brain injury patients are different, even among themselves, in their energy requirements and response to nutritional therapy. This implies that there are other factors that affect the energy intake of these patients and enhance the incidence of malnutrition.

This dissertation study examines the nutritional status of TBI patients upon admission to the intensive care unit (ICU) and during their hospital stay to describe baseline status, detect changes in nutritional status over 7 days, and identify the factors …

Elastin Like Polypeptides As Drug Delivery Vehicles In Regenerative Medicine Applications, Alex Leonard

USF Tampa Graduate Theses and Dissertations

Elastin like polypeptides (ELPs) are a class of naturally derived biomaterials that are non-immunogenic, genetically encodable, and biocompatible making them ideal for a variety of biomedical applications, ranging from drug delivery to tissue engineering. Also, ELPs undergo temperature-mediated inverse phase transitioning, which allows them to be purified in a relatively simple manner from bacterial expression hosts. Being able to genetically encode ELPs allows for the incorporation of bioactive peptides and functionalization of ELPs. This work utilizes ELPs for regenerative medicine and drug delivery.

The goal of the first study was to synthesize a biologically active epidermal growth factor-ELP (EGF-ELP) fusion …