Locally Resonant Metasurface For Low-Frequency Transmissive Underwater Acoustic Waves, 2023 Wuhan University of Technology
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, 2023 Edith Cowan University
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. …
Effect Of Decorating Super Paramagnetic Iron Oxide Nanoparticles With Silver Nanoparticles On Their Magneto-Photo Thermal Heating Efficiency, 2023 Minnesota State University, Mankato
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 …
Architecture Of Heptagonal Metallo-Macrocycles Via Embedding Metal Nodes Into Its Rigid Backbone, 2023 Department of Physics, Old Dominion University, Norfolk, Virginia 23529, United States
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, …
Exploring Strategies To Protect Nonprofit Organizations’ Assets From Fraud, 2023 Walden University
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 …
Application Of Multi-Scale Computational Techniques To Complex Materials Systems, 2023 University of Kentucky
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 …
Novel Development Of A Low-Cost, Micrometer-Scale Tip-Enhanced Raman Spectroscopy System, 2023 Virginia Commonwealth University
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. …
Superheating Field In Superconductors With Nanostructured Surfaces, 2023 Virginia Military Institute
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 Hsh 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 …
Traversing With Quantitative Fidelity Through The Glass Transition Of Amorphous Polymers: Modeling The Thermodynamic Dilatational Flow Of Polycarbonate, 2023 University of Nebraska-Lincoln
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., 2023 Wichita State University
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, 2023 Università degli Studi di Padova
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 …
Correction: Nanoscale Imaging Of Antiferromagnetic Domains In Epitaxial Films Of Cr2o3 Via Scanning Diamond Magnetic Probe Microscopy, 2023 University of Nebraska-Lincoln
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
Numerical Study Of The Time-Periodic Electroosmotic Flow Of Viscoelastic Fluid Through A Short Constriction Microchannel, 2023 Old Dominion University
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 …
Synthesis Of Quasi-Freestanding Graphene Films Using Radical Species Formed In Cold Plasmas, 2023 West Virginia University
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 …
Inventions In The Area Of Nanotechnologies And Nanomaterials. Part I, 2023 Old Dominion University
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 …
Roles Of Mtorc1 And Mtorc2 In Epilepsy And Network Changes Induced By Pten Loss, 2023 University of Vermont
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 …
Developing Mesoporous Silica Nanoparticle-Based Stimuli-Responsive Nanocarriers For Delivery Of Small Molecule Therapeutics Against Colon Cancer Cells, 2023 University of South Dakota
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 …
Carrier Transport Engineering In Wide Bandgap Semiconductors For Photonic And Memory Device Applications, 2022 New Jersey Institute of Technology
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, 2022 New Jersey Institute of Technology
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) …
Carbon-Al Interface Effect On The Performance Of Ionic Liquid-Based Supercapacitor At 3 V And 65 OC, 2022 1. Department of Chemical Engineering, Tsinghua University, Beijing, 100084, China;
Carbon-Al Interface Effect On The Performance Of Ionic Liquid-Based Supercapacitor At 3 V And 65 OC, Zhen-Zhen Ye, Shu-Ting Zhang, Xin-Qi Chen, Jin Wang, Ying Jin, Chao-Jie Cui, Lei Zhang, Lu-Ming Qian, Gang Zhang, Wei-Zhong Qian
Journal of Electrochemistry
Ionic liquid (IL) electrolyte-based supercapacitors (SCs) have advantages of high operating voltage window, high energy density and nonflammability, as compared to conventional acetonitrile-based organic electrolyte SCs, and are typically suitable for the large-scale energy storage in the era of carbon neutrality full of renewable, but unstable electricity. However, current efforts were concentrated on the study with coin-cell type of IL-SCs, and less has been reported on the pouch type of IL-SCs for a long cycling time yet. To fabricate a reliable SC for the life time test or for the accelerated aging test under high temperature, one should concern the …