Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Engineering (7)
- Materials Science and Engineering (4)
- Condensed Matter Physics (3)
- Nanoscience and Nanotechnology (3)
- Optics (3)
-
- Biochemistry, Biophysics, and Structural Biology (2)
- Biomedical Engineering and Bioengineering (2)
- Biophysics (2)
- Life Sciences (2)
- Anthropology (1)
- Bioimaging and Biomedical Optics (1)
- Biological and Chemical Physics (1)
- Chemical Engineering (1)
- Mechanical Engineering (1)
- Nuclear (1)
- Other Physics (1)
- Quantum Physics (1)
- Social and Behavioral Sciences (1)
- Social and Cultural Anthropology (1)
- Keyword
-
- Films (2)
- Graphene (2)
- Anchored ribbons (1)
- Angle resolve photoemission spectroscopy (1)
- Antiferroelectric (1)
-
- Beta2-micro globulin (1)
- CQED (1)
- Carbon nanotubes (1)
- Chemical Synthesis (1)
- Confinement (1)
- Correlation functions (1)
- Critical biocultural approach (1)
- Critical fluctuation (1)
- Dephasing (1)
- Design of experiments (1)
- Dielectric relaxation (1)
- Dynamic Light Scattering (1)
- Elastic moduli (1)
- Exciton-phonon interaction (1)
- Ferroelectric (1)
- Fiducials (1)
- Finite element modeling (1)
- Fluorescence mode (1)
- Frequency comb (1)
- Gadolinium (1)
- Gas Sensing (1)
- Gas sensing (1)
- Giant unilamellar vesicle (1)
- Heterostructures (1)
- Homogeneous linewidth (1)
Articles 1 - 17 of 17
Full-Text Articles in Physics
Reduced Dimensionality Effects In Gd-Based Magnetocaloric Materials, Hillary Faith Belliveau
Reduced Dimensionality Effects In Gd-Based Magnetocaloric Materials, Hillary Faith Belliveau
USF Tampa Graduate Theses and Dissertations
Magnetic refrigeration based on the magnetocaloric effect (MCE) is a promising alternative to conventional gas compression based cooling techniques. Understanding impacts of reduced dimensionality on the magnetocaloric response of a material such as Gadolinium (Gd) or its alloys is essential in optimizing the performance of cooling devices, which is also the overall goal of this thesis. We have determined, in the first part of the thesis, that laminate structures of pure Gd produced by magnetron sputtering have several disadvantages. The target material (pure Gd), ultra-high vacuum components, and the electrical energy it takes to run the manufacturing process are all …
Resonant Light Scattering From Semiconductor Quantum Dots, Kumarasiri Konthasinghe
Resonant Light Scattering From Semiconductor Quantum Dots, Kumarasiri Konthasinghe
USF Tampa Graduate Theses and Dissertations
In this work, resonant laser spectroscopy has been utilized in two major projects --resonance fluorescence measurements in solid-state quantum-confined nanostructures and laser-induced fluorescence measurements in gases. The first project focuses on studying resonant light-matter interactions in semiconductor quantum dots "artificial atoms" with potential applications in quantum information science. Of primary interest is the understanding of fundamental processes and how they are affected by the solid-state matrix. Unlike atoms, quantum dots are susceptible to a variety of environmental influences such as phonon scattering and spectral diffusion. These interactions alter the desired properties of the scattered light and hinder uses in certain …
Confinement Effects And Magnetic Interactions In Magnetic Nanostructures, Kristen Lee Stojak Repa
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 …
Surface Properties Of Titanium Dioxide And Its Structural Modifications By Reactions With Transition Metals, Sandamali Halpegamage
Surface Properties Of Titanium Dioxide And Its Structural Modifications By Reactions With Transition Metals, Sandamali Halpegamage
USF Tampa Graduate Theses and Dissertations
Surfaces of metal oxides play a vital role in many technologically important applications. The surfaces of titanium dioxide, in particular, show quite promising properties that can be utilized in solid-state gas sensing and photocatalysis applications. In the first part of this dissertation we investigate these properties of TiO2 surfaces through a vigorous surface scientific approach. In the second part, we investigate the possibilities of modifying the TiO2 surfaces by depositing multi-component transition metal oxide monolayers so that the properties of bare TiO2 surface can be influenced in a beneficial way. For instance, via formation of new surface …
Novel Magnetic Nanostructures For Enhanced Magnetic Hyperthermia Cancer Therapy, Zohreh Nemati Porshokouh
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 …
The Role Of Partial Surface Charge Compensation In The Properties Of Ferroelectric And Antiferroelectric Thin Films, Elena Glazkova
The Role Of Partial Surface Charge Compensation In The Properties Of Ferroelectric And Antiferroelectric Thin Films, Elena Glazkova
USF Tampa Graduate Theses and Dissertations
Ferroelectric and antiferroelectric ultrathin films have attracted a lot of attention recently due to their remarkable properties and their potential to allow for device miniaturization in numerous applications. However, when the ferroelectric films are scaled down, it brings about an unavoidable depolarizing field. A partial surface charge compensation allows to control the residual depolarizing field and manipulate the properties of ultrathin ferroelectric films. In this dissertation we take advantage of atomistic first-principles-based simulations to expand our understanding of the role of the partial surface charge compensation in the properties of ferroelectric and antiferroelectric ultrathin films.
The application of our computational …
Effect Of Void Fraction On Transverse Shear Modulus Of Advanced Unidirectional Composites, Jui-He Tai
Effect Of Void Fraction On Transverse Shear Modulus Of Advanced Unidirectional Composites, Jui-He Tai
USF Tampa Graduate Theses and Dissertations
In composite materials, transverse shear modulus is a critical moduli parameter for designing complex composite structures. For dependable mathematical modeling of mechanical behavior of composite materials, an accurate estimate of the moduli parameters is critically important as opposed to estimates of strength parameters where underestimation may lead to a non-optimal design but still would give one a safe one.
Although there are mechanical and empirical models available to find transverse shear modulus, they are based on many assumptions. In this work, the model is based on a three-dimensional elastic finite element analysis with multiple cells. To find the shear modulus, …
Polymer Characteristics Of Polyelectrolyte Polypeptides, Jorge Monreal
Polymer Characteristics Of Polyelectrolyte Polypeptides, Jorge Monreal
USF Tampa Graduate Theses and Dissertations
Polypeptides are polymerized chains of amino acids linked covalently through peptide bonds. Polyelectrolyte polypeptides are polypeptides with electrolyte repeating groups. Several amino acids contain ionizable side chains which result in charge distributions when dissolved in aqueous solutions. This dissertation is motivated by a desire to gain knowledge of polyelectrolyte polypeptides as recent advances in chemical synthesis of polypeptides have made possible the fabrication of designed polypeptides that do not naturally occur in nature. Potential applications of newly designed polypeptides span the range from medical to clothing and energy even to robotics.
In this dissertation we compare the characteristic behavior of …
Preparation And Characterization Of Van Der Waals Heterostructures, Horacio Coy Diaz
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 …
Microcavity Enhanced Raman Scattering, Benjamin James Petrak
Microcavity Enhanced Raman Scattering, Benjamin James Petrak
USF Tampa Graduate Theses and Dissertations
Raman scattering can accurately identify molecules by their intrinsic vibrational frequencies, but its notoriously weak scattering efficiency for gases presents a major obstacle to its practical application in gas sensing and analysis. This work explores the use of high finesse (50 000) Fabry-Pérot microcavities as a means to enhance Raman scattering from gases. A recently demonstrated laser ablation method, which carves out a micromirror template on fused silica--either on a fiber tip or bulk substrates-- was implemented, characterized, and optimized to fabricate concave micromirror templates ~10 µm diameter and radius of curvature. The fabricated templates were coated with a high-reflectivity …
Inquiry Of Lipid Membranes Interacting With Functional Peptides And Polyphenol Drug Molecules, Chian Sing Ho
Inquiry Of Lipid Membranes Interacting With Functional Peptides And Polyphenol Drug Molecules, Chian Sing Ho
USF Tampa Graduate Theses and Dissertations
Cellular membranes are important targets for many membrane-active peptides and drug compounds. Here we are interested in deciphering how lipid membranes are perturbed by several membrane-active molecules, including the transmembrane domain of the influenza M2 protein (M2TM), aggregates formed by a synthetic polyglutamine peptide, and three polyphenol compounds (i.e., tamoxifen, genistein, and verapamil). We employ phase-separated ternary lipid model membranes in the form of giant unilamellar vesicles (GUVs) to simulate raft-like structures that have been proposed to govern many important processes in plasma membranes (e.g., intracellular singling and trafficking). Specifically, we use fluorescent microscopy to interrogate how those membrane additives …
Nano-Photonic Waveguides For Chemical And Biomedical Sensing, Surya Venkatasekhar Cheemalapati
Nano-Photonic Waveguides For Chemical And Biomedical Sensing, Surya Venkatasekhar Cheemalapati
USF Tampa Graduate Theses and Dissertations
In this dissertation, advances in the fields of Photonics, and Plasmonics, and specifically, single cell analysis and waveguide sensing will be addressed. The first part of the dissertation is on Finite Difference Time Domain (FDTD) optimization and experimental demonstration of a nano-scale instrument that allows sensing at the cellular and subcellular levels. A new design of plasmonic coupler into a nanoscale waveguide is proposed and optimized using FDTD simulations. Following this, a subcellular nanoendoscope that can locally excite fluorescence in labelled cell organelles and collect the emitted fluorescent light for detailed spectrum analysis is fabricated and tested. The nanoendoscope has …
Costumbres, Creencias, Y “Lo Normal”: A Biocultural Study On Changing Prenatal Dietary Practices In A Rural Tourism Community In Costa Rica, Allison Rachel Cantor
Costumbres, Creencias, Y “Lo Normal”: A Biocultural Study On Changing Prenatal Dietary Practices In A Rural Tourism Community In Costa Rica, Allison Rachel Cantor
USF Tampa Graduate Theses and Dissertations
This study explores the relationship between tourism, the nutrition transition, and prenatal dietary practices in the Monteverde Zone, Costa Rica. This rural tourism community, located in the central highlands of Costa Rica, has seen rapid growth and development since the tourism boom in the early 1990s, leading to changes in the local food system and increased food insecurity. This investigation added to this work by identifying the ways that prenatal dietary practices have shifted over time in the context of increased tourism and the concomitant nutrition transition, and by describing the relationship between food insecurity and nutritional status among pregnant …
Structure-Interaction Effects In Novel Nanostructured Materials, Nam B. Le
Structure-Interaction Effects In Novel Nanostructured Materials, Nam B. Le
USF Tampa Graduate Theses and Dissertations
Recent advances in experimental and computational methods have opened up new directions in graphene fundamental studies. In addition to understanding the basic properties of this material and its quasi-one dimensional structures, significant efforts are devoted to describing their long ranged dispersive interactions. Other two-dimensional materials, such as silicene, germanene, and transition metal dichalcogenides, are also being investigated aiming at finding complementary to graphene systems with other "wonder" properties. The focus of this work is to utilize first principles simulations methods to build our basic knowledge of structure-interaction relations in two-dimensional materials and design their properties. In particular, mechanical folding and …
Increasing 18f-Fdg Pet/Ct Capabilities In Radiotherapy For Lung And Esophageal Cancer Via Image Feature Analysis, Jasmine Alexandria Oliver
Increasing 18f-Fdg Pet/Ct Capabilities In Radiotherapy For Lung And Esophageal Cancer Via Image Feature Analysis, Jasmine Alexandria Oliver
USF Tampa Graduate Theses and Dissertations
Positron Emission Tomography (PET) is an imaging modality that has become increasingly beneficial in Radiotherapy by improving treatment planning (1). PET reveals tumor volumes that are not well visualized on computed tomography CT or MRI, recognizes metastatic disease, and assesses radiotherapy treatment (1). It also reveals areas of the tumor that are more radiosensitive allowing for dose painting - a non-homogenous dose treatment across the tumor (1). However, PET is not without limitations. The quantitative unit of PET images, the Standardized Uptake Value (SUV), is affected by many factors such as reconstruction algorithm, patient weight, and tracer uptake time (2). …
Biophysical Investigation Of Amyloid Formation And Their Prion-Like Self-Replication, Mentor Mulaj
Biophysical Investigation Of Amyloid Formation And Their Prion-Like Self-Replication, Mentor Mulaj
USF Tampa Graduate Theses and Dissertations
Growth and deposition of amyloid fibrils, polymers of proteins with a cross beta-sheet structure, are associated with a significant number of human pathologies including Alzheimer’s disease, Parkinson’s disease, prion diseases, type II diabetes, and senile systematic or dialysis-related amyloidoses. The broader objective of my research is to identify the basic mechanisms regulating nucleation and growth of amyloid fibrils. There is increasing evidence that amyloid formation may proceed along at least two distinct assembly pathways for the formation of rigid fibrils. One pathway involves the nucleated polymerization of the characteristic rigid fibrils from partially denatured monomers and the other proceeds via …
Exciton Dynamics And Many Body Interactions In Layered Semiconducting Materials Revealed With Non-Linear Coherent Spectroscopy, Prasenjit Dey
Exciton Dynamics And Many Body Interactions In Layered Semiconducting Materials Revealed With Non-Linear Coherent Spectroscopy, Prasenjit Dey
USF Tampa Graduate Theses and Dissertations
Atomically thin, semiconducting transition metal dichalogenides (TMDs), a special class of layered semiconductors, that can be shaped as a perfect two dimensional material, have garnered a lot of attention owing to their fascinating electronic properties which are achievable at the extreme nanoscale. In contrast to graphene, the most celebrated two-dimensional (2D) material thus far; TMDs exhibit a direct band gap in the monolayer regime. The presence of a non-zero bandgap along with the broken inversion symmetry in the monolayer limit brands semiconducting TMDs as the perfect candidate for future optoelectronic and valleytronics-based device application. These remarkable discoveries demand exploration of …