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Full-Text Articles in Nanoscience and Nanotechnology

Editorial: Disease Biomarker Analysis Based On Optical Biosensing, Tianshu Chen, Fanben Meng, Binwu Ying, Xiaoli Zhu Apr 2023

Editorial: Disease Biomarker Analysis Based On Optical Biosensing, Tianshu Chen, Fanben Meng, Binwu Ying, Xiaoli Zhu

Department of Mechanical and Materials Engineering: Faculty Publications

Disease biomarker analysis has become a crucial tool for diagnosing and evaluating disease prognosis, especially with the increasing understanding of diseases at the molecular level. Abnormalities in various biomarkers can indicate diseased states, and can be used to rapidly and specifically detect and quantify diseases using optical biosensing techniques (Gao et al., 2023). Optical biosensing techniques have several advantages over traditional methods including higher sensitivity, specificity, and faster analysis times (Plikusiene and Ramanaviciene, 2023). It also allows for non-invasive sample collection. With advancements in optical biosensing technology, many medical conditions including cancers, infectious diseases, and autoimmune disorders can be accurately …


Region-Specified Inverse Design Of Absorption And Scattering In Nanoparticles By Using Machine Learning, Alex Vallone, Nooshin M. Estakhri, Nasim Mohammadi Estrakhri Apr 2023

Region-Specified Inverse Design Of Absorption And Scattering In Nanoparticles By Using Machine Learning, Alex Vallone, Nooshin M. Estakhri, Nasim Mohammadi Estrakhri

Engineering Faculty Articles and Research

Machine learning provides a promising platform for both forward modeling and the inverse design of photonic structures. Relying on a data-driven approach, machine learning is especially appealing for situations when it is not feasible to derive an analytical solution for a complex problem. There has been a great amount of recent interest in constructing machine learning models suitable for different electromagnetic problems. In this work, we adapt a region-specified design approach for the inverse design of multilayered nanoparticles. Given the high computational cost of dataset generation for electromagnetic problems, we specifically investigate the case of a small training dataset, enhanced …


Considering The Influence Of Coronary Motion On Artery‑Specific Biomechanics Using Fluid–Structure Interaction Simulation, Nicholas A. T. Fogell, Miten Patel, Pan Yang, Roosje M. Ruis, David B. Garcia, Jarka Naser, Fotios Savvopoulos, Clint Davies Taylor, Anouk L. Post, Ryan M. Pedrigi, Ranil De Silva, Rob Krams Apr 2023

Considering The Influence Of Coronary Motion On Artery‑Specific Biomechanics Using Fluid–Structure Interaction Simulation, Nicholas A. T. Fogell, Miten Patel, Pan Yang, Roosje M. Ruis, David B. Garcia, Jarka Naser, Fotios Savvopoulos, Clint Davies Taylor, Anouk L. Post, Ryan M. Pedrigi, Ranil De Silva, Rob Krams

Department of Mechanical and Materials Engineering: Faculty Publications

The endothelium in the coronary arteries is subject to wall shear stress and vessel wall strain, which influences the biology of the arterial wall. This study presents vessel-specific fluid–structure interaction (FSI) models of three coronary arteries, using directly measured experimental geometries and boundary conditions. FSI models are used to provide a more physiologically complete representation of vessel biomechanics, and have been extended to include coronary bending to investigate its effect on shear and strain. FSI both without- and with-bending resulted in significant changes in all computed shear stress metrics compared to CFD (p = 0.0001). Inclusion of bending within …


A Threshold Helium Leakage Detection Switch With Ultra Low Power Operation, Sulaiman Mohaidat, Fadi M. Alsaleem Apr 2023

A Threshold Helium Leakage Detection Switch With Ultra Low Power Operation, Sulaiman Mohaidat, Fadi M. Alsaleem

Department of Mechanical and Materials Engineering: Faculty Publications

Detecting helium leakage is important in many applications, such as in dry cask nuclear waste storage systems. This work develops a helium detection system based on the relative permittivity (dielectric constant) difference between air and helium. This difference changes the status of an electrostatic microelectromechanical system (MEMS) switch. The switch is a capacitive-based device and requires a very negligible amount of power. Exciting the switch’s electrical resonance enhances the MEMS switch sensitivity to detect low helium concentration. This work simulates two different MEMS switch configurations: a cantilever-based MEMS modeled as a single-degreefreedom model and a clamped-clamped beam MEMS molded using …


Crystalline–Amorphous Nanostructures: Microstructure, Property And Modelling, Binqiang Wei, Lin Li, Lin Shao, Jian Wang Apr 2023

Crystalline–Amorphous Nanostructures: Microstructure, Property And Modelling, Binqiang Wei, Lin Li, Lin Shao, Jian Wang

Department of Mechanical and Materials Engineering: Faculty Publications

Crystalline metals generally exhibit good deformability but low strength and poor irradiation tolerance. Amorphous materials in general display poor deformability but high strength and good irradiation tolerance. Interestingly, refining characteristic size can enhance the flow strength of crystalline metals and the deformability of amorphous materials. Thus, crystalline–amorphous nanostructures can exhibit an enhanced strength and an improved plastic flow stability. In addition, high-density interfaces can trap radiation-induced defects and accommodate free volume fluctuation. In this article, we review crystalline–amorphous nanocomposites with characteristic microstructures including nanolaminates, core–shell microstructures, and crystalline/amorphous-based dual-phase nanocomposites. The focus is put on synthesis of characteristic microstructures, deformation …


Plasmon Enhanced Quantum Properties Of Single Photon Emitters With Hybrid Hexagonal Boron Nitride Silver Nanocube Systems, Mohammadjavad Dowran, Andrew Butler, Suvechhya Lamichhane, Adam Erickson, Ufuk Kilic, Sy_Hwang Liou, Christos Argyropoulos, A. Laraoui Apr 2023

Plasmon Enhanced Quantum Properties Of Single Photon Emitters With Hybrid Hexagonal Boron Nitride Silver Nanocube Systems, Mohammadjavad Dowran, Andrew Butler, Suvechhya Lamichhane, Adam Erickson, Ufuk Kilic, Sy_Hwang Liou, Christos Argyropoulos, A. Laraoui

Department of Mechanical and Materials Engineering: Faculty Publications

Hexagonal boron nitride (hBN) has emerged as a promising ultrathin host of single photon emitters (SPEs) with favorable quantum properties at room temperature, making it a highly desirable element for integrated quantum photonic networks. One major challenge of using these SPEs in such applications is their low quantum efficiency. Recent studies have reported an improvement in quantum efficiency by up to two orders of magnitude when integrating an ensemble of emitters such as boron vacancy defects in multilayered hBN flakes embedded within metallic nanocavities. However, these experiments have not been extended to SPEs and are mainly focused on multiphoton effects. …


Pamam- Cyclodextrin Conjugate Upregulates Brain-Derived Neurotropic Factor In Arpe-19 Cells, Gopika Ashokan Mar 2023

Pamam- Cyclodextrin Conjugate Upregulates Brain-Derived Neurotropic Factor In Arpe-19 Cells, Gopika Ashokan

USF Tampa Graduate Theses and Dissertations

Background: Traumatic Brain Injury (TBI) is a major contributor to death and disability due to motorvehicle accidents, sports, physical abuse, and battlefield injuries. The primary insult to the brain leads to inflammation, vascular dysfunction, and oxidative stress in the brain as well as in the eye. This leads to loss of Retinal Ganglion Cells (RGCs) and downregulation of Brain derived Neurotopic Factor (BDNF). BDNF is a neurotrophic factor that binds to Tropomyosin Receptor Kinase B (TrkB) receptor to promote cell growth, survival, and differentiation. Current treatment strategies do not promote neuronal regeneration. Therefore, novel treatments are needed to restore vision …


Graphene Twistronics: Tuning The Absorption Spectrum And Achieving Metamaterial Properties, Ammar Armghan, Meshari Alsharari, Khaled Aliqab, Osamah Alsalman, Juveriya Parmar, Shobhit K. Patel Mar 2023

Graphene Twistronics: Tuning The Absorption Spectrum And Achieving Metamaterial Properties, Ammar Armghan, Meshari Alsharari, Khaled Aliqab, Osamah Alsalman, Juveriya Parmar, Shobhit K. Patel

Department of Mechanical and Materials Engineering: Faculty Publications

Graphene twistronics using multilayer graphene is presented in such a way that it provides a metamaterial effect. This manuscript also analyzes the prediction of behavior using machine learning. The metamaterial effect is achieved by twisting the graphene layers. Graphene twistronics is a new concept for changing the electrical and optical properties of bilayer graphene by applying a small angle twist between the layers. The angle twists of 5o, 10o, and 15o are analyzed for the proposed graphene twistronics design. Tuning in the absorption spectrum is achieved by applying small twists to the angles of the …


Heterogeneous Sensor Data Fusion For Multiscale, Shape Agnostic Flaw Detection In Laser Powder Bed Fusion Additive Manufacturing, Benjamin Bevans, Christopher Barrett, Thomas Spears, Aniruddha Gaikwad, Alex Riensche, Harold (Scott) Halliday, Prahalada Rao Mar 2023

Heterogeneous Sensor Data Fusion For Multiscale, Shape Agnostic Flaw Detection In Laser Powder Bed Fusion Additive Manufacturing, Benjamin Bevans, Christopher Barrett, Thomas Spears, Aniruddha Gaikwad, Alex Riensche, Harold (Scott) Halliday, Prahalada Rao

Department of Mechanical and Materials Engineering: Faculty Publications

We developed and applied a novel approach for shape agnostic detection of multiscale flaws in laser powder bed fusion (LPBF) additive manufacturing using heterogenous in-situ sensor data. Flaws in LPBF range from porosity at the micro-scale (< 100 μm), layer related inconsistencies at the meso-scale (100 μm to 1 mm) and geometry-related flaws at the macroscale (> 1 mm). Existing data-driven models are primarily focused on detecting a specific type of LPBF flaw using signals from one type of sensor. Such approaches, which are trained on data from simple cuboid and cylindrical-shaped coupons, have met limited success when used for detecting multiscale flaws in complex LPBF parts. The objective of this work is to develop a heterogenous sensor data fusion …


Mechanical Properties And Performance Of A Novel Nano-Engineered Unitized Composite With Quasi-Isotropic Layup, Brian Matthew Pudlo Mar 2023

Mechanical Properties And Performance Of A Novel Nano-Engineered Unitized Composite With Quasi-Isotropic Layup, Brian Matthew Pudlo

Theses and Dissertations

Carbon nanotubes (CNTs) exhibit outstanding mechanical, electrical, and thermal properties, but are a challenge to effectively implement into macroscopic composites for aerospace applications. This research investigates the mechanical properties and performance of a newly developed hybrid NanoStitch composite, alongside a control polymer matrix composite, at room temperature. Both composite material systems investigated in this work have quasi-isotropic layup. Monotonic tension-tofailure, tension-tension fatigue, and creep tests were performed to characterize the performance of the composites under cyclic and sustained loading. Experimental results obtained for the quasi-isotropic NanoStitch composite were compared to those obtained for the quasi-isotropic control composite. The properties and …


Highly Dispersed Pt Nanoparticles Root In Single-Atom Fe Sites In Ldhs Toward Efficient Methanol Oxidation, Qing-Cheng Meng, Lin-Bo Jin, Meng-Ze Ma, Xue-Qing Gao, Ai-Bing Chen, Dao-Jin Zhou, Xiao-Ming Sun Feb 2023

Highly Dispersed Pt Nanoparticles Root In Single-Atom Fe Sites In Ldhs Toward Efficient Methanol Oxidation, Qing-Cheng Meng, Lin-Bo Jin, Meng-Ze Ma, Xue-Qing Gao, Ai-Bing Chen, Dao-Jin Zhou, Xiao-Ming Sun

Journal of Electrochemistry

Active and durable electrocatalysts for methanol oxidation reaction are of critical importance to the commercial viability of direct methanol fuel cell, which has already attracted growing popularities. However, current methanol oxidation electrocatalysts fall far short of expectations and suffer from excessive use of noble metal, mediocre activity, and rapid decay. Here we report the Pt anchored on NiFe-LDHs surface hybrid for stable methanol oxidation in alkaline media. Based on the high intrinsic methanol oxidation activity of Pt nanoparticles, the substrates NiFe-LDHs further enhanced anti-poisoning ability and maintained unaffected stability after 200,000 s cycle test compared to commercial Pt/C catalyst. The …


Using Nanomaterials As Excellent Immobilisation Layer For Biosensor Design, Azeez Olayiwola Idris, Seyi Philemon Akanji, Benjamin O. Orimolade, Foluke Omobola Grace Olorundare, Shohreh Azizi, Bhekie Mamba, Malik Maaza Feb 2023

Using Nanomaterials As Excellent Immobilisation Layer For Biosensor Design, Azeez Olayiwola Idris, Seyi Philemon Akanji, Benjamin O. Orimolade, Foluke Omobola Grace Olorundare, Shohreh Azizi, Bhekie Mamba, Malik Maaza

Research outputs 2022 to 2026

The endless development in nanotechnology has introduced new vitality in device fabrication including biosensor design for biomedical applications. With outstanding features like suitable biocompatibility, good electrical and thermal conductivity, wide surface area and catalytic activity, nanomaterials have been considered excellent and promising immobilisation candidates for the development of high-impact biosensors after they emerged. Owing to these reasons, the present review deals with the efficient use of nanomaterials as immobilisation candidates for biosensor fabrication. These include the implementation of carbon nanomaterials—graphene and its derivatives, carbon nanotubes, carbon nanoparticles, carbon nanodots—and MXenes, likewise their synergistic impact when merged with metal oxide nanomaterials. …


Polyethersulfone Thin-Film Nanocomposite Membrane Embedded With Amine-Functionalized Graphene Oxide For Desalination Applications, Ahmed Bahaeldin Jan 2023

Polyethersulfone Thin-Film Nanocomposite Membrane Embedded With Amine-Functionalized Graphene Oxide For Desalination Applications, Ahmed Bahaeldin

Theses and Dissertations

Thin-film nanocomposite (TFN) desalination membranes were prepared based on a polyethersulfone (PES) support, where the polyamide (PA) layer was embedded with amine-functionalized graphene oxide (GO). The effect of adding various concentrations of functionalized and un-functionalized GO on the desalination performance, hydrophilicity, and morphology of the membranes was additionally assessed throughout this work. Scanning electron microscopy (SEM) measurements were used to assess the morphology of the membranes in combination with Brunauer-Emmett-Teller (BET) analysis. Contact angle measurements were used to gauge the hydrophilicity of the synthesized membranes. The membrane with the best desalination performance contained 1x10-3 wt/vol% of functionalized GO in …


Non-Equilibrium Colloidal Phenomena In Magnetic Fields And Photoillumination: From Controlling Living Microbots To Understanding Microplastics, Ahmed Al Harraq Jan 2023

Non-Equilibrium Colloidal Phenomena In Magnetic Fields And Photoillumination: From Controlling Living Microbots To Understanding Microplastics, Ahmed Al Harraq

LSU Doctoral Dissertations

Colloids are a ubiquitous class of materials composed of microscopic particles suspended in a continuous phase which are found in everyday products and in nature. Colloids are also useful models for studying the spontaneous arrangement of matter from individual building blocks to mesophases. Standard treatment of colloid science is based on the assumption of equilibrium conditions, as defined in traditional thermodynamics. However, novel assembly mechanisms and motility are unlocked by pushing colloids away from equilibrium using external energy. In addition, many colloids in nature and in industrial applications exchange energy and mass with the surrounding environment thus behaving in a …


Research Progress In Cucurbit[N]Uril-Based Metal Nanomaterials For Electrocatalytic Applications, Zong-Nan Wei, Min-Na Cao, Rong Cao Jan 2023

Research Progress In Cucurbit[N]Uril-Based Metal Nanomaterials For Electrocatalytic Applications, Zong-Nan Wei, Min-Na Cao, Rong Cao

Journal of Electrochemistry

Metal nanomaterials have exhibited excellent performance in electrocatalytic applications, but they still face the problems of poor stability and limited regulation strategies. It is an efficient strategy for greatly enhanced catalytic activity and stability by introducing a second component. In this review, we provide the sketch for the combination of metal nanomaterials and cucurbit[n]urils (CB[n]s) in electrocatalytic applications. CB[n]s are a series of macrocycles with rigid structure, high stability, and function groups for coordinating with metal sites, which make them promising to stabilize and modulate the metal nanomaterials for ideal performance. The discussion classifies the roles of CB[n]s, involving CB[n]s …


Interfaces In Dynamic Brittle Fracture Of Pmma: A Peridynamic Analysis, Longzhen Wang, Javad Mehrmashhadi, Florin Bobaru Jan 2023

Interfaces In Dynamic Brittle Fracture Of Pmma: A Peridynamic Analysis, Longzhen Wang, Javad Mehrmashhadi, Florin Bobaru

Department of Mechanical and Materials Engineering: Faculty Publications

Recent experiments in bonded PMMA layers have shown dramatic changes in dynamic crack growth characteristics depending on the interface location and toughness. In this paper we present a peridynamic (PD) analysis of this phenomenon and determine three elements that are essential in a model reproducing the observed fracture behavior: (1) softening near the crack tip to account for changes in PMMA due to heat-generation induced by the high strain rates reached around the crack tip in dynamic fracture; (2) independent extension (mode I) and shear (mode II) modes of fracture; (3) a two-parameter fracture model, which matches both strength and …


Locally Resonant Metasurface For Low-Frequency Transmissive Underwater Acoustic Waves, Zhong Chen, Shenghong Guan, Qiang Xie, Zheng Li, Zhongmei Gao, Mehrdad Negahban Jan 2023

Locally Resonant Metasurface For Low-Frequency Transmissive Underwater Acoustic Waves, Zhong Chen, Shenghong Guan, Qiang Xie, Zheng Li, Zhongmei Gao, Mehrdad Negahban

Department of Mechanical and Materials Engineering: Faculty Publications

Introduction: Acoustic metasurfaces for underwater wave manipulation have great potential use, but the strong solid-fluid interaction caused by impedance closeness between the structure and water brings design difficulty, especially in the low-frequency range.

Methods: Here a locally resonant metasurface for transmissive underwater acoustic waves is proposed using finite element method for which each metasurface unit consists of one channel and three subunits. Each subunit has one plate and two rubber spacers to form a resonator. By changing the height ratio of the plate over the subunit, arbitrary phase shifts within the full 2π coverage can be obtained at …


Solar-Light-Responsive Nanomaterials For The Photoelectrocatalytic Degradation Of Stubborn Pollutants, Benjamin O. Orimolade, Azeez O. Idris, Seyi Philemon Akanji, Folahan A. Adekola, Shohreh Azizi, Malik Maaza, Bhekie Mamba Jan 2023

Solar-Light-Responsive Nanomaterials For The Photoelectrocatalytic Degradation Of Stubborn Pollutants, Benjamin O. Orimolade, Azeez O. Idris, Seyi Philemon Akanji, Folahan A. Adekola, Shohreh Azizi, Malik Maaza, Bhekie Mamba

Research outputs 2022 to 2026

Due to the ever increasing demand for cleaner water, a remarkable focus has been on the use of nanomaterials in wastewater treatment application. Photoelectrocatalytic (PEC) degradation, an advanced oxidation process which combines light and electrical energy, has been identified as a suitable technique capable of achieving total mineralisation of recalcitrant organic pollutants in wastewater. PEC degradation is non-selective, environmentally friendly and possesses great efficiency. The efficiency of PEC degradation has been enhanced by fabricating the photoanodes on a nanoscale with distinct morphologies. These nanostructured photoanodes have been extensively used for the removal of pharmaceuticals, dyes and phenolic water from wastewater. …


Architecture Of Heptagonal Metallo-Macrocycles Via Embedding Metal Nodes Into Its Rigid Backbone, A.M.Shashika D. Wijerathna, He Zhao, Qiangqiang Dong, Qixia Bai, Zhiyuan Jiang, Jie Yuan, Jun Wang, Mingzhao Chen, Markus Zirnheld, Rockwell T. Li, Yuan Zhang, Yiming Li, Pingshan Wang Jan 2023

Architecture Of Heptagonal Metallo-Macrocycles Via Embedding Metal Nodes Into Its Rigid Backbone, A.M.Shashika D. Wijerathna, He Zhao, Qiangqiang Dong, Qixia Bai, Zhiyuan Jiang, Jie Yuan, Jun Wang, Mingzhao Chen, Markus Zirnheld, Rockwell T. Li, Yuan Zhang, Yiming Li, Pingshan Wang

College of Sciences Posters

Metal-organic macrocycles have received increasing attention not only due to their versatile applications such as molecular recognition, compounds encapsulation, anti-bacteria and others, but also for their important role in the study of structure-property relationship at nano scale. However, most of the constructions utilize benzene ring as the backbone, which restricts the ligand arm angle in the range of 60, 120 and 180 degrees. Thus, the topologies of most metallo-macrocycles are limited as triangles and hexagons, and explorations of using other backbones with large angles and the construction of metallo-macrocycles with more than six edges are very rare.

In this study, …


Correction: Nanoscale Imaging Of Antiferromagnetic Domains In Epitaxial Films Of Cr2o3 Via Scanning Diamond Magnetic Probe Microscopy, Adam Erickson, Syed Qamar Abbas Shah, Ather Mahmood, Ilja Fescenko, Rupak Timalsina, Christian H. Binek, Abdelghani Laraoui Jan 2023

Correction: Nanoscale Imaging Of Antiferromagnetic Domains In Epitaxial Films Of Cr2o3 Via Scanning Diamond Magnetic Probe Microscopy, Adam Erickson, Syed Qamar Abbas Shah, Ather Mahmood, Ilja Fescenko, Rupak Timalsina, Christian H. Binek, Abdelghani Laraoui

Department of Mechanical and Materials Engineering: Faculty Publications

Correction for ‘Nanoscale imaging of antiferromagnetic domains in epitaxial films of Cr2O3 via scanning diamond magnetic probe microscopy’ by Adam Erickson et al., RSC Adv., 2023, 13, 178–185, https:// doi.org/10.1039/D2RA06440E


Exploring Strategies To Protect Nonprofit Organizations’ Assets From Fraud, Georjean W. Trinkle Jan 2023

Exploring Strategies To Protect Nonprofit Organizations’ Assets From Fraud, Georjean W. Trinkle

Walden Dissertations and Doctoral Studies

Community action agencies serve low-income individuals, families, and communities. Community action agencies may be at risk of fraud if they do not have board members with the knowledge to implement effective governance strategies to protect the organization's assets from fraud. Grounded in agency theory, the purpose of this qualitative multiple case study was to explore effective governance strategies that some community action board members use to protect their organization's assets from fraud. The participants were three board members of two community action agencies in New Jersey who implemented effective governance strategies to protect the organization's assets from fraud. Data were …


Traversing With Quantitative Fidelity Through The Glass Transition Of Amorphous Polymers: Modeling The Thermodynamic Dilatational Flow Of Polycarbonate, Mehrdad Negahban, Wenlong Li, Jean-Marc Saiter, Laurent Delbreilh, Kyle Strabala, Zheng Li Jan 2023

Traversing With Quantitative Fidelity Through The Glass Transition Of Amorphous Polymers: Modeling The Thermodynamic Dilatational Flow Of Polycarbonate, Mehrdad Negahban, Wenlong Li, Jean-Marc Saiter, Laurent Delbreilh, Kyle Strabala, Zheng Li

Department of Mechanical and Materials Engineering: Faculty Publications

We follow the assumption that the dilatational response of glassy polymers can be characterized by a back-stress type analog that includes a thermal expansion for each elastic component, and with a viscosity that is dependent on the expansion of the elastic back stress component. To this, we add the assumption of an unloaded equilibrium temperature that correlates to the past processing through the viscous flow. After setting this in a thermodynamically consistent structure, the elastic, elastic backstress, thermal expansion, back-stress thermal expansion, heat capacity and viscous damping are evaluated using existing experiments for the response of polycarbonate over the glassy …


An Efficient And Low-Cost Method To Create High-Density Nitrogen-Vacancy Centers In Cvd Diamond For Sensing Applications., Prem Bahadur Karki, Rupak Timalsina, Mohammadjavad Dowran, Ayodimeji E. Aregbesola, Abdelghani Laraoui, Kapildeb Ambal Jan 2023

An Efficient And Low-Cost Method To Create High-Density Nitrogen-Vacancy Centers In Cvd Diamond For Sensing Applications., Prem Bahadur Karki, Rupak Timalsina, Mohammadjavad Dowran, Ayodimeji E. Aregbesola, Abdelghani Laraoui, Kapildeb Ambal

Department of Mechanical and Materials Engineering: Faculty Publications

The negatively charged Nitrogen-Vacancy (NV-) center in diamond is one of the most versatile and robust quantum sensors suitable for quantum technologies, including magnetic field and temperature sensors. For precision sensing applications, densely packed NV- centers within a small volume are preferable due to benefiting from 1/√𝑁 sensitivity enhancement (N is the number of sensing NV centers) and efficient excitation of NV centers. However, methods for quickly and efficiently forming high concentrations of NV- centers are in development stage. We report an efficient, low-cost method for creating high-density NV- centers production from a relatively …


Peridynamic Simulation Of Elastic Wave Propagation By Applying The Boundary Conditions With The Surface Node Method, Francesco Scabbia, Mirco Zaccariotto, Ugo Galvanetto, Florin Bobaru Jan 2023

Peridynamic Simulation Of Elastic Wave Propagation By Applying The Boundary Conditions With The Surface Node Method, Francesco Scabbia, Mirco Zaccariotto, Ugo Galvanetto, Florin Bobaru

Department of Mechanical and Materials Engineering: Faculty Publications

Peridynamics is a novel nonlocal theory able to deal with discontinuities, such as crack initiation and propagation. Near the boundaries, due to the incomplete nonlocal region, the peridynamic surface effect is present, and its reduction relies on using a very small horizon, which ends up being expensive computationally. Furthermore, the imposition of nonlocal boundary conditions in a local way is often required. The surface node method has been proposed to solve both the aforementioned issues, providing enhanced accuracy near the boundaries of the body. This method has been verified in the cases of quasi-static elastic problems and diffusion problems evolving …


Application Of Multi-Scale Computational Techniques To Complex Materials Systems, Mujan N. Seif Jan 2023

Application Of Multi-Scale Computational Techniques To Complex Materials Systems, Mujan N. Seif

Theses and Dissertations--Chemical and Materials Engineering

The applications of computational materials science are ever-increasing, connecting fields far beyond traditional subfields in materials science. This dissertation demonstrates the broad scope of multi-scale computational techniques by investigating multiple unrelated complex material systems, namely scandate thermionic cathodes and the metallic foam component of micrometeoroid and orbital debris (MMOD) shielding. Sc-containing "scandate" cathodes have been widely reported to exhibit superior properties compared to previous thermionic cathodes; however, knowledge of their precise operating mechanism remains elusive. Here, quantum mechanical calculations were utilized to map the phase space of stable, highly-faceted and chemically-complex W nanoparticles, accounting for both finite temperature and chemical …


Roles Of Mtorc1 And Mtorc2 In Epilepsy And Network Changes Induced By Pten Loss, Erin R. Cullen Jan 2023

Roles Of Mtorc1 And Mtorc2 In Epilepsy And Network Changes Induced By Pten Loss, Erin R. Cullen

Graduate College Dissertations and Theses

Gene variants that hyperactivate the mTOR signaling pathway are a major cause of treatment-resistant epilepsy. The mTOR pathway influences neuron function through two distinct complexes, mTORC1 and mTORC2. Pten loss of function (LOF) hyperactivates both mTOR complexes, and is thus a useful model for testing the effects of independent mTORC1 or mTORC2 hyperactivity on epilepsy and underlying neuropathology. Here, we evaluated the impact of genetic inactivation of the mTOR complexes in two mouse models of Pten LOF-driven epilepsy. In a germline GFAP-driven Pten LOF model targeting neurons in the dentate gyrus and cerebellum, a mild epilepsy phenotype was not rescued …


Development Of High Kinetic Inductance Superconducting Nanowire Devices On High Permittivity Strontium Titanate Substrates, Jamie Timmons Jan 2023

Development Of High Kinetic Inductance Superconducting Nanowire Devices On High Permittivity Strontium Titanate Substrates, Jamie Timmons

UNF Graduate Theses and Dissertations

This thesis involves the fabrication and characterization of devices made from two different superconducting materials: yttrium barium copper oxide (YBCO), a high-TC complex oxide, and niobium nitride (NbN), a low-TC transition metal nitride. Both types of devices are fabricated on strontium titanate substrates, which provides a good lattice match to YBCO and also an extremely large permittivity at low temperature. We demonstrate that wet etching of YBCO thin films via bromine can be a viable microfrabriation technique for the material. Using approximately 35 nm thick epitaxially grown YBCO on an STO substrate, we were able to fabricate YBCO “microwires” with …


Synthesis Of Quasi-Freestanding Graphene Films Using Radical Species Formed In Cold Plasmas, Michael A. Mathews Jr. Jan 2023

Synthesis Of Quasi-Freestanding Graphene Films Using Radical Species Formed In Cold Plasmas, Michael A. Mathews Jr.

Graduate Theses, Dissertations, and Problem Reports

For over a decade, the Stinespring laboratory has investigated scalable, plasma assisted synthesis (PAS) methods for the growth of graphene films on silicon carbide (SiC). These typically utilized CF4-based inductively coupled plasma (ICP) with reactive ion etching (RIE) to selectively etch silicon from the SiC lattice. This yielded a halogenated carbon-rich surface layer which was then annealed to produce the graphene layers. The thickness of the films was controlled by the plasma parameters, and overall, the process was readily scalable to the diameter of the SiC wafer.

The PAS process reproducibly yielded two- to three-layer thick graphene films …


Developing Mesoporous Silica Nanoparticle-Based Stimuli-Responsive Nanocarriers For Delivery Of Small Molecule Therapeutics Against Colon Cancer Cells, Nisitha Lakmal Wellala Wijewantha Jan 2023

Developing Mesoporous Silica Nanoparticle-Based Stimuli-Responsive Nanocarriers For Delivery Of Small Molecule Therapeutics Against Colon Cancer Cells, Nisitha Lakmal Wellala Wijewantha

Dissertations and Theses

This dissertation delves into the innovative application of mesoporous silica nanoparticles (MSNs) for targeted drug delivery in colorectal cancer (CRC), one of the most prevalent and deadly forms of cancer worldwide. The initial focus of the research is on developing enzyme-responsive MSNs loaded with veratridine (VTD), an alkaloid derived from natural sources that demonstrates potent anticancer activity. The nanoparticles have been engineered to deliver VTD selectively to CRC cells, releasing the payload upon being exposed to specific enzymes primarily secreted by these cells. This strategy has dual advantages of amplifying the anticancer effects while minimizing potential side effects on healthy …


Novel Development Of A Low-Cost, Micrometer-Scale Tip-Enhanced Raman Spectroscopy System, John Yates Jan 2023

Novel Development Of A Low-Cost, Micrometer-Scale Tip-Enhanced Raman Spectroscopy System, John Yates

Theses and Dissertations

Modern scientific instruments are significant capital investments for universities. These investments can be outside of the funding capabilities of some smaller universities or departments and can be a significant barrier in the pursuit of scientific breakthroughs. This project aims to provide a template for universities or research groups to upgrade, at a reasonable price, an existing Raman spectroscopy system to a Tip-Enhanced Raman Spectroscopy (TERS) system. This system can serve as a permanent upgrade to an existing system or as a bridge necessary to prove the viability of a research path before significant capital investment in a commercial TERS system. …