Nanoscience and Nanotechnology Commons^™

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

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 …

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. …

Inventions In The Area Of Nanotechnologies And Nanomaterials. Part I, Leonid A. Ivanov, Li Da Xu, Zhanna V. Pisarenko, Svetlana R. Muminova, Nadezda G. Miloradova

Information Technology & Decision Sciences Faculty Publications

Introduction. Advanced technologies inspire people by demonstrating the latest achievements (materials, methods, systems, technologies, devices etc.) that dramatically change the world. This, first of all, concerns nanotechnological inventions designed by scientists, engineers and specialists from different countries. Main part. The article provides an abstract overview of inventions of scientists, engineers and specialists from different countries: Germany, Russia, China, USA et al. The results of the creative activity of scientists, engineers and specialists, including inventions in the field of nanotechnology and nanomaterials allow, when introduced to industry, achieving a significant effect in construction, housing and communal services, and related sectors of …

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 …

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 …

Superconductivity In 2d Janus Monolayers And Bilayers, M Munib Ul Hassan Noor Ul Taqi

Chulalongkorn University Theses and Dissertations (Chula ETD)

Janus transition metal dichalcogenides (J-TMDCs) is a new class of materials which shares the same honey-comb structure as graphene and conventional transition metal dichalcogenides (TMDCs) in monolayer. They have versatile physical and chemical properties which mainly feature out from their broken out of plane symmetry. This asymmetry results in an intrinsic electric field orthogonal to their plan. The presence of an intrinsic electric field gives rise to many novel properties like the Rashba effect, increased charge carrier concentration, Schottky barrier, excitons, and superconductivity. Also, they exist in multiple structural phases like, 2H, 1T, 1T' with the electrical properties shifting from …

Value-Added Natural Fiber As A Biocompatible Substrate For Chemical Sensor Applications, Wisarttra Phamonpon

Chulalongkorn University Theses and Dissertations (Chula ETD)

This dissertation focuses on the improvement and value added of natural fiber extracted from the UHT milk carton waste, and raw silk cocoon to fabricate the biocompatible substrate for chemical sensors, principally in colorimetric and electrochemical sensors, which is allocated in 3 main parts. Initially, the background studying of the surface modification and the function of natural fiber based chemical sensor for food quality control and clinical diagnosis will be explained in a review article. Subsequently, the development of recycled cellulose from UHT milk carton waste as a novel substrate of dual lactate sensor for milk spoilage indication will be …

Numerical Study Of The Time-Periodic Electroosmotic Flow Of Viscoelastic Fluid Through A Short Constriction Microchannel, Jianyu Ji, Shizhi Qian, Armani Marie Parker, Xiaoyu Zhang

Mechanical & Aerospace Engineering Faculty Publications

Electroosmotic flow (EOF) is of utmost significance due to its numerous practical uses in controlling flow at micro/nanoscales. In the present study, the time-periodic EOF of a viscoelastic fluid is statistically analyzed using a short 10:1 constriction microfluidic channel joining two reservoirs on either side. The flow is modeled using the Oldroyd-B (OB) model and the Poisson-Boltzmann model. The EOF of a highly concentrated polyacrylamide (PAA) aqueous solution is investigated under the combined effects of an alternating current (AC) electric field and a direct current (DC) electric field. Power-law degradation is visible in the energy spectra of the velocity fluctuations …

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 …

Synthesis, Characterization, And Application Of Chitosan Nanoparticles For In Vitro Studies On Hela Cancer Cells, Rejeena Jha

Graduate Theses/Dissertations

Chitosan is a fibrous substance that is derived from chitin, a natural substance in the shells of crustaceans. It possesses all the necessary qualities for being used as carrier for the transport of drugs and genes into tumor, such as biodegradability, biocompatibility, hydrophilicity, and non-toxicity and cationic in nature. Ionic gelation method was used to synthesize chitosan (CS) nanoparticles (NPs). Ionic gelation is a very benign process chemically that requires mixing a CS aqueous solution with a sodium tripolyphosphate (TPP) aqueous solution at room temperature. In addition, a surfactant polyethylene oxide (PEO) alone and a diblock copolymer of PEO and …

Effect Of Decorating Super Paramagnetic Iron Oxide Nanoparticles With Silver Nanoparticles On Their Magneto-Photo Thermal Heating Efficiency, Anthony Joseph Afful

All Graduate Theses, Dissertations, and Other Capstone Projects

Cancer treatment is rather dangerous to the body, often involving many secondary effects, including nausea, hair loss, and weight fluctuations. The search for non-invasive, highly efficient, and targetable treatments ameliorates these issues. Super paramagnetic iron oxide nanoparticles (SPIONS) have been used for other medical purposes such as magnetic resonance imaging contrast agent and is being extensively studied as a potential candidate for many cancer therapeutic and diagnostic approaches due to its biocompatibility and superior magnetic properties. When subjected to an external alternating magnetic field SPIONS generate heat mainly due to the friction of the SPIONS against the fluid it is …

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 …

Electrolyte Synthesis And Engineering For Alkali Metal Batteries, Yiwen Zhang

Dartmouth College Ph.D Dissertations

Batteries have been in increasing demand over the last decade for portable electronic devices, electric vehicles, and grid-scale energy storage systems. While the electrode materials define the characteristic features of a battery system, the composition of the electrolyte is of critical importance and needs to be engineered for different battery systems to ensure superior electrochemical performance. In this thesis, the basic functionality and fundamental mechanism of the electrolytes in battery systems are first introduced. Then, three major electrolyte engineering strategies are demonstrated, including electrolyte composition formulation, electrolyte-electrode component modification, and function-oriented electrolyte design. Firstly, the low-temperature capacity restraint of lithium …

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 …

Superheating Field In Superconductors With Nanostructured Surfaces, W. P. M. R. Pathirana, A. Gurevich

Physics Faculty Publications

We report calculations of a dc superheating field H_sh in superconductors with nanostructured surfaces. Numerical simulations of the Ginzburg-Landau (GL) equations were performed for a superconductor with an inhomogeneous impurity concentration, a thin superconducting layer on top of another superconductor, and superconductor-insulator-superconductor (S-I-S) multilayers.The superheating field was calculated taking into account the instability of the Meissner state with a nonzero wavelength along the surface, which is essential for realistic values of the GL parameter κ. Simulations were done for the materials parameters of Nb and Nb₃Sn at different values of κ and the mean free paths. We …

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

Graduate Theses, Dissertations, and Problem Reports (ETD)

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 …

Carrier Transport Engineering In Wide Bandgap Semiconductors For Photonic And Memory Device Applications, Ravi Teja Velpula

Dissertations

Wide bandgap (WBG) semiconductors play a crucial role in the current solid-state lighting technology. The AlGaN compound semiconductor is widely used for ultraviolet (UV) light-emitting diodes (LEDs), however, the efficiency of these LEDs is largely in a single-digit percentage range due to several factors. Until recently, AlInN alloy has been relatively unexplored, though it holds potential for light-emitters operating in the visible and UV regions. In this dissertation, the first axial AlInN core-shell nanowire UV LEDs operating in the UV-A and UV-B regions with an internal quantum efficiency (IQE) of 52% are demonstrated. Moreover, the light extraction efficiency of this …

Faceted Nanomaterial Synthesis, Characterizations And Applications In Reactive Electrochemical Membrane Filtration, Qingquan Ma

Dissertations

Facet engineering of nanomaterials, especially metals and metal oxides has become an important strategy for tuning catalytic properties and functions from heterogeneous catalysis to electrochemical catalysis, photocatalysis, biomedicine, fuel cells, and gas sensors. The catalytic properties are highly related to the surface electronic structures, surface electron transport characteristics, and active center structures of catalysts, which can be tailored by surface facet control. The aim of this doctoral dissertation research is to study the facet-dependent properties of metal or metal oxide nanoparticles using multiple advanced characterization techniques. Specifically, the novel atomic force microscope-scanning electrochemical microscope (AFM-SECM) and density functional theory (DFT) …

Amphiphilic Block Copolymers And The Applications In Therapeutics Delivery, Jie Dou

Dissertations

Well-defined thermo-responsive triblock copolymers containing polyethylene oxide (PEO) and poly(N-isopropyl acrylamide) PNIPAM are synthesized by a type of living controlled polymerization, named iniferter polymerization. The polymers are amphiphilic in nature and are self-assembled into a micelle. Their properties and application are characterized and investigated in this work.

Foremost, the initiator of the polymerization (iniferter) is designed and synthesized by condensation polymerization, where PEO is incorporated into the structure to improve biocompatibility, which has great potential for biological application. Moreover, this iniferter reagent could be applied to more than 70 percent of vinyl monomers.

NIPAM, a commercial vinyl monomer, is chosen …