Observation And Control Of Photoemission And Electric Field Enhancement Of Plasmonic Antennas Through Photoemission Electron Microscopy,
2022
Portland State University
Observation And Control Of Photoemission And Electric Field Enhancement Of Plasmonic Antennas Through Photoemission Electron Microscopy, Christopher M. Scheffler
Dissertations and Theses
Photoemission electron microscopy (PEEM) is an imaging method which uses electrons excited through the photoelectric effect to characterize a sample surface with nanometer-level resolution. In PEEM, a high intensity laser excites electrons from the surface of the material and electron optics are used to form an image from the intensity and spatial distribution of the photoemission from the sample. The goal of this research was to study and maximize light confinement, which was accomplished using plasmonic nanostructures. Surface plasmons represent oscillations in the electron density of a material and can occur along the transition interface between a metal and a …
Uv Space Imager Enclosure Coating,
2022
California Polytechnic State University, San Luis Obispo
Uv Space Imager Enclosure Coating, David Silva Cortez, Victor Alexander Rempel Dekhtyar, Maria L. Muñoz
Mechanical Engineering
The goal of this project is to reduce the amount of stray light entering an ultraviolet (UV) imager through absorption. This report outlines the use of ZnO nanoparticles mixed in an epoxy matrix for use in a CubeSat enclosure. Through testing, our team verified that the ZnO and epoxy coating experienced a peak absorption between 360-370 nm. The epoxy mixture with the .75% by weight ZnO nanoparticles absorbed up to 99.9 % of UV light at its peak. The effect on material properties, such as Young’s modulus and ultimate tensile strength, was also tested. Tensile tests demonstrated that adding ZnO …
Monolithic Integration Of Hybrid
Perovskite Single Crystals With
Silicon For Highly Sensitive X - Ray
Detectors,
2022
Lincoln , NE
Monolithic Integration Of Hybrid Perovskite Single Crystals With Silicon For Highly Sensitive X - Ray Detectors, Jinsong Huang, Wei Wei
Department of Mechanical and Materials Engineering: Faculty Publications
Perovskite single crystal X - ray radiation detector devices including an X - ray wavelength - responsive active layer including an organolead trihalide perovskite single crystal, a substrate layer comprising an oxide, and a binding layer disposed between the active layer and the substrate layer. The binding layer including a binding molecule having a first functional group that bonds to the organolead trihalide perovskite single crystal and a second functional bonds with the oxide. Inclusion of the binding layer advantageously reduces device noise while retaining signal intensity.
Electrocatalytic "Volcano-Type" Effect Of Nano-Tio2 (A)/(R) Phase Content In Pt/Tio2-CnX Catalyst,
2022
Institute of Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, 100083, China;
Electrocatalytic "Volcano-Type" Effect Of Nano-Tio2 (A)/(R) Phase Content In Pt/Tio2-CnX Catalyst, Ai-Lin Cui, Yang Bai, Hong-Ying Yu, Hui-Min Meng
Journal of Electrochemistry
The relationship between the electrochemical activity of fuel cell catalysts and Pt particle size, as well as the catalyst support and co-catalyst is still unclear. In this work, FESEM, XRD, BET, TEM and CV techniques were adopted to investigate the effects of TiO2 anatase (A)/rutile (R) phases content on the electrochemical activity of Pt electrocatalyst. The results showed that the anatase-rutile phase transformation occurred during the heat treatment of TiO2 at 700 ~ 900 oC accompanied by the growth of two-phase crystalline size, and anatase was completely transformed into rutile at 900 oC. TEM results revealed …
Biofouling Behaviors Of Pure Titanium Surface Polarized At Different Potentials,
2022
1. Center for Marine Materials Corrosion and Protection, College of Materials, Xiamen University, Xiamen 361005, Fujian, China;
Biofouling Behaviors Of Pure Titanium Surface Polarized At Different Potentials, Zhao-Xia Dai, Da-Jiang Zheng, Guang-Ling Song, Dan-Qing Feng, Pei Su
Journal of Electrochemistry
Titanium (Ti) and its alloys are commonly used as engineering materials. Although they have been widely used in marine environments, they are also facing serious threats of biofouling. Therefore, it is necessary to investigate the relationship between electrochemical behavior and bioaffinity of titanium oxide film in seawater to explore effective surface treatment technology to reduce biofouling. In this work, the cathodic potential of -0.8 VSCE and the passivation potential of 0.5 VSCE were directly applied to the TA2 Ti in artificial seawater for potentionstatic polarization treatment to prepare two kinds of surface films with different states and then …
Passivation Of Defects In
Perovskite Materials For Improved
Solar Cell Efficiency And Stability,
2022
Lincoln , NE
Passivation Of Defects In Perovskite Materials For Improved Solar Cell Efficiency And Stability, Jinsong Huang, Xiaopeng Zheng
Department of Mechanical and Materials Engineering: Faculty Publications
Semiconductor devices , and methods of forming the same , include a cathode layer , an anode layer , and an active layer disposed between the cathode layer and the anode layer , wherein the active layer includes a perovskite layer . A passivation layer is disposed directly on a surface of the active layer between the cathode layer and the active layer , the passivation layer including a layer of material that passivates both cationic and anionic defects in the surface of the active layer .
Application Of Bismuth Oxychloride As A Colorimetric Uv Sensor Material,
2022
University of New Mexico
Application Of Bismuth Oxychloride As A Colorimetric Uv Sensor Material, Kyle James Troche
Nanoscience and Microsystems ETDs
Sunlight contains about 9% UV radiation with roughly one-third of it penetrating the atmosphere and reaching the Earth’s surface. UV radiation from the sun is classified into three different types: UVA (315- 499 nm), UVB (280- 314nm), and UVC (100- 279 nm). Prolonged exposure to artificial UV radiation or direct sunlight can still induce many adverse effects such as sunburn, weakening of the immune system, and skin cancer. A wide variety of photoresistor, photodiode and colorimetric UV sensors are currently being researched to help monitor UV radiation. Our research is focused on developing a colorimetric UV sensor that is inherently …
Controlling The Emission Of Volatile Platinum Oxides To The Vapor Phase In Diesel Oxidation Catalysts,
2022
University of New Mexico - Main Campus
Controlling The Emission Of Volatile Platinum Oxides To The Vapor Phase In Diesel Oxidation Catalysts, Arnab Ghosh
Nanoscience and Microsystems ETDs
Pt-based catalysts are used for the treatment of emissions from vehicles, particularly in Diesel oxidation catalysts (DOCs). Three-way catalysts are treated at temperatures ranging from 950℃-1050℃ while DOCs are aged at 800℃ for 50 hrs. At 800°C, Pt reacts with O2 to form PtO2 which has a high vapor pressure and can be transported through the vapor phase. These accelerated aging conditions lead to the formation of large Pt particles causing a loss of catalytic activity. In this thesis, we used model thin-film catalysts that made it possible to quantify the emission of Pt to the vapor phase …
Thermal Management Using Liquid-Vapor Phase Change In Nanochannels,
2022
Syracuse University
Thermal Management Using Liquid-Vapor Phase Change In Nanochannels, Sajag Poudel
Dissertations - ALL
Superior wettability of porous medium marks their potential to be used in the field of thermal management employing phase-change heat transfer. Comprehending the phenomena of wicking and liquid-vapor phase-change in micro/nano structured surfaces are key aspects towards advancing heat transfer solutions. In this work, fundamental understanding of droplet wicking, thin-film evaporation, and their subsequent application of heat-flux removal for cooling technology is first reported. The latter part of the dissertation is related to the disjoining pressure driven flow of nanoscale liquid film and liquid-vapor phase change in nano confinement. First, experimental and numerical investigation of droplet wicking in ∼728 nm …
Resistive Pulse Sensing Of Protein Unfolding And Transport In Solid-State Nanopores,
2022
Southern Methodist University
Resistive Pulse Sensing Of Protein Unfolding And Transport In Solid-State Nanopores, Jugal Saharia
Mechanical Engineering Research Theses and Dissertations
Solid-state nanopore sensors have attracted considerable attraction as a tool for solution-based single-molecule studies and have been successfully utilized for characterization of biomolecules such as nucleic acids, proteins, glycans, viruses, etc. Among these, characterization of proteins has been more challenging due to their charge heterogeneity and the complex energy landscape associated with different protein conformations. Presented in this thesis is the fabrication of solid-state nanopores and their application for characterizing proteins and understanding their transport through nanopores. Fabrication of nanometer-sized pores in SixNy membranes was achieved using the conventional controlled dielectric breakdown method as well as a …
Surface Acoustic Wave Characterization And Interdigitated Transducer Optimization For Studying Stress-Enhanced Phenomena,
2022
University of New Mexico
Surface Acoustic Wave Characterization And Interdigitated Transducer Optimization For Studying Stress-Enhanced Phenomena, Brian D. Rummel
Nanoscience and Microsystems ETDs
Surface acoustic wave devices have not yet achieved their full potential as the effects of standing acoustic fields on stress-sensitive phenomena in semiconductor systems have been largely unexplored. From this perspective, it is necessary to develop novel methods to characterize surface acoustic wave devices quantitatively and prepare an experimental platform to probe stress-enhanced processes. In this dissertation, interdigitated transducer devices are fabricated on gallium arsenide to evaluate their potential impact on strain-enhanced phenomena. A novel Raman characterization technique characterizes the surface stress induced by a standing acoustic field, revealing stress values on the order of 108 Pa. FEM software …
Enhancing Optical And Thermal Properties Of Nanofibrous Films Inspired By The White Beetle Scale,
2022
University of New Mexico
Enhancing Optical And Thermal Properties Of Nanofibrous Films Inspired By The White Beetle Scale, Bokyung Park
Nanoscience and Microsystems ETDs
The Cyphochilus white beetle has received significant attention recently for its exceptional visible-light-scattering properties, owing to the beetle scale's anisotropic nano-fibrillar network structure. Inspiration from the remarkable optical properties of these biological species has directed research efforts to fabricating biomimetic nano-fibrillar structures with polymer materials. In this work, electrospun silk fibroin polymer films reproduce the white beetle scale's anisotropic nature to draw on its optical scattering properties and further improve the radiative-cooling capabilities of silk fabrics. An anisotropically restructured silk film with a mean fiber diameter of a few hundred nanometers substantially increases optical scattering strength in the visible spectrum …
Photocatalytic Degradation Of Organic Contaminants By Titania Particles Produced By Flame Spray Pyrolysis,
2022
Mississippi State University
Photocatalytic Degradation Of Organic Contaminants By Titania Particles Produced By Flame Spray Pyrolysis, Noah Babik
Theses and Dissertations
Advanced oxidation of organic pollutants with TiO2 photocatalysts is limited due to the wide bandgap of TiO2, 3.2 eV, which requires ultraviolet (UV) radiation. When nanosized TiO2 is modified by carbon doping, charge recombination is inhibited and the bandgap is narrowed, allowing for efficient photodegradation under visible light. Here, we propose a flame spray pyrolysis (FSP) technique to create TiO2. The facile process of FSP has been successful in preparing highly crystalline TiO2 nanoparticles. Using the same procedure to deposit TiO2 onto biochar, the photocatalyst was doped by the carbonaceous material. The morphology, crystalline and electronic structure of the FSP …
Monolithically Integrated Microscale Pressure Sensor On An Optical Fiber Tip,
2022
Air Force Institute of Technology
Monolithically Integrated Microscale Pressure Sensor On An Optical Fiber Tip, Jeremiah C. Williams, Hengky Chandrahalim
AFIT Patents
A passive microscopic Fabry-Pérot Interferometer (FPI) pressure sensor includes an optical fiber and a three-dimensional microscopic optical enclosure. The three-dimensional microscopic optical enclosure includes tubular side walls having lateral pleated corrugations and attached to a cleaved tip of the optical fiber to receive a light signal. An optically reflecting end wall is distally engaged to the tubular side walls to enclose a trapped quantity of gas that longitudinally positions the optically reflecting end wall in relation to ambient air pressure, changing a distance traveled by a light signal reflected back through the optical fiber.
Hinged Temperature-Immune Self-Referencing Fabry–Pérot Cavity Sensors,
2022
Air Force Institute of Technology
Hinged Temperature-Immune Self-Referencing Fabry–Pérot Cavity Sensors, Jeremiah C. Williams, Hengky Chandrahalim
AFIT Patents
A passive microscopic Fabry-Pérot Interferometer (FPI) sensor includes a three-dimensional microscopic optical structure formed on a cleaved tip of the optical fighter using a two-photon polymerization process on a photosensitive polymer by a three-dimensional micromachining device. The three-dimensional microscopic optical structure having a hinged optical layer pivotally connected to a distal portion of a suspended structure. A reflective layer is deposited on a mirror surface of the hinged optical layer while in an open position. The hinged optical layer is subsequently positioned in the closed position to align the mirror surface to at least partially reflect a light signal back …
A Versatile Python Package For Simulating Dna Nanostructures With Oxdna,
2022
University of Arkansas, Fayetteville
A Versatile Python Package For Simulating Dna Nanostructures With Oxdna, Kira Threlfall
Computer Science and Computer Engineering Undergraduate Honors Theses
The ability to synthesize custom DNA molecules has led to the feasibility of DNA nanotechnology. Synthesis is time-consuming and expensive, so simulations of proposed DNA designs are necessary. Open-source simulators, such as oxDNA, are available but often difficult to configure and interface with. Packages such as oxdna-tile-binding pro- vide an interface for oxDNA which allows for the ability to create scripts that automate the configuration process. This project works to improve the scripts in oxdna-tile-binding to improve integration with job scheduling systems commonly used in high-performance computing environments, improve ease-of-use and consistency within the scripts compos- ing oxdna-tile-binding, and move …
The Growth Of Polarization Domains In Ultrathin Ferroelectric Films Seeded By The Tip Of An Atomic Force Microscope,
2022
University of Arkansas, Fayetteville
The Growth Of Polarization Domains In Ultrathin Ferroelectric Films Seeded By The Tip Of An Atomic Force Microscope, Mohammad Zamani-Alavijeh, Timothy A. Morgan, Adrian V. Kuchuk, Gregory J. Salamo
Physics Faculty Publications and Presentations
Piezoresponse force microscopy is used to study the velocity of the polarization domain wall in ultrathin ferroelectric barium titanate (BTO) films grown on strontium titanate (STO) substrates by molecular beam epitaxy. The electric field due to the cone of the atomic force microscope tip is demonstrated as the dominant electric field for domain expansion in thin films at lateral distances greater than about one tip diameter away from the tip. The velocity of the domain wall under the applied electric field by the tip in BTO for thin films (less than 40 nm) followed an expanding process given by Merz's …
Surface-Functionalized Chemiresistive Films That Exploit H-Bonding, Cation-Pi, And Metal-Halide Interactions.,
2022
University of Louisville
Surface-Functionalized Chemiresistive Films That Exploit H-Bonding, Cation-Pi, And Metal-Halide Interactions., Prasadanie Karunarathna Adhihetty
Electronic Theses and Dissertations
The development of gas sensors for detection of volatile organic compounds (VOCs) has been of interest in the sensing field for decades. To date, the use of metal nanoparticle-based chemiresistors for trace VOC detection, particularly gold nanoparticle-based sensors, is of great interest due to their high chemical stability, ease of synthesis, unique optical properties, large surface to volume ratio, and high level of conductivity. Much effort has been devoted towards gold monolayer protected clusters (Au MPCs) as chemiresistors to detect harmful VOCs. The present thesis documents the results of our efforts to exploit the advantages of functionalized Au MPCs chemiresistors …
Atomic Force Microscopy Based Dna Sensing And Manipulation,
2022
University of Arkansas, Fayetteville
Atomic Force Microscopy Based Dna Sensing And Manipulation, Matthew Shubert
Mechanical Engineering Undergraduate Honors Theses
Sequencing DNA provides a positive impact for the biomedical community by understanding a wide variety of applications such as human genetics, disease, and pathogens. The reason the Arkansas Micro & Nano Systems lab is involved with research in DNA sequencing is due to the current, leading industry method. Nanopore sequencing was developed by Oxford Nanopore Technology in which its sequencing method separates double stranded DNA to electrically characterize individual nucleotides traveling through a charged nanopore. Unfortunately, nanopore sequencing uses biological materials that require a shelf life and drives high cost. Therefore, the Arkansas Micro & Nano Systems lab has developed …
Towards Highly Sensitive Capacitance Measurements Of A Quantum Anomalous Hall Phase In Van Der Waal Heterostructures,
2022
University of Nevada, Las Vegas
Towards Highly Sensitive Capacitance Measurements Of A Quantum Anomalous Hall Phase In Van Der Waal Heterostructures, Kayla Cerminara
UNLV Theses, Dissertations, Professional Papers, and Capstones
One of the pioneering achievements in condensed matter physics of the 20th century is the observation of the quantum Hall e↵ect (QHE) in which the Hall resistance in a two-dimensional (2D) sample takes on quantized values in the presence of a strong perpendicular magnetic field. The precise quantization of the hall resistance to one part in a billion has provided a practical, worldwide resistance standard. A long-standing goal has been to realize a similar state of matter but without the need of a strong quantizing magnetic field. The quantum anomalous Hall e↵ect (QAHE) is such a state that is predicted …
