Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Astrophysics and Astronomy (27)
- Optics (22)
- Engineering (20)
- Electrical and Computer Engineering (17)
- Electromagnetics and Photonics (15)
-
- Condensed Matter Physics (11)
- Plasma and Beam Physics (9)
- Other Physics (7)
- Aerospace Engineering (2)
- Engineering Physics (2)
- Nuclear (2)
- American Studies (1)
- Arts and Humanities (1)
- Atomic, Molecular and Optical Physics (1)
- Biochemistry, Biophysics, and Structural Biology (1)
- Biological and Chemical Physics (1)
- Biophysics (1)
- Chemistry (1)
- Computer Engineering (1)
- Education (1)
- Educational Assessment, Evaluation, and Research (1)
- Elementary Particles and Fields and String Theory (1)
- Energy Policy (1)
- Fluid Dynamics (1)
- Life Sciences (1)
- Materials Chemistry (1)
- Public Affairs, Public Policy and Public Administration (1)
- Public Policy (1)
- Institution
-
- University of Central Florida (28)
- Air Force Institute of Technology (14)
- Georgia State University (14)
- Brigham Young University (13)
- University of Tennessee, Knoxville (10)
-
- Clemson University (9)
- William & Mary (8)
- New Jersey Institute of Technology (6)
- Wright State University (6)
- Western Michigan University (5)
- Michigan Technological University (3)
- Trinity University (3)
- American University in Cairo (2)
- Missouri University of Science and Technology (2)
- Old Dominion University (2)
- Utah State University (2)
- Virginia Commonwealth University (2)
- Butler University (1)
- Claremont Colleges (1)
- Embry-Riddle Aeronautical University (1)
- Oberlin (1)
- Portland State University (1)
- The University of Maine (1)
- University of Missouri, St. Louis (1)
- University of South Florida (1)
- Keyword
-
- Department of Physics (6)
- Spectroscopy (5)
- Fiber optics (3)
- GaN (3)
- Infrared (3)
-
- Semiconductor (3)
- Terahertz (3)
- Active galaxies (2)
- Astrometry (2)
- Astronomy (2)
- Bragg mirror (2)
- Gallium nitride (2)
- Imaging (2)
- Laser beams--Scattering (2)
- Lasers (2)
- Optical constants (2)
- Optical fibers (2)
- Plasma (2)
- Si (2)
- Solar physics (2)
- Stars (2)
- ZnO (2)
- Impurity States. (1)
- 1PA (1)
- 2PA (1)
- 3d display (1)
- 40 Eridani (1)
- ANC (1)
- ATST (1)
- Absorption (1)
- Publication
-
- Electronic Theses and Dissertations (29)
- Theses and Dissertations (29)
- Dissertations (11)
- Physics and Astronomy Dissertations (11)
- Dissertations, Theses, and Masters Projects (8)
-
- Masters Theses (7)
- Browse all Theses and Dissertations (6)
- Doctoral Dissertations (6)
- All Theses (5)
- All Dissertations (4)
- Dissertations, Master's Theses and Master's Reports - Open (3)
- Physics & Astronomy Honors Theses (3)
- Physics and Astronomy Theses (3)
- All Graduate Theses and Dissertations, Spring 1920 to Summer 2023 (2)
- Archived Theses and Dissertations (2)
- Dissertations and Theses (1)
- Electrical & Computer Engineering Theses & Dissertations (1)
- Honors Papers (1)
- Master's Theses - Daytona Beach (1)
- Physics Theses & Dissertations (1)
- Pomona Senior Theses (1)
- USF Tampa Graduate Theses and Dissertations (1)
- Undergraduate Honors Thesis Collection (1)
Articles 121 - 137 of 137
Full-Text Articles in Physics
Three-Dimensional Micron-Scale Metal Photonic Crystals Via Multi-Photon Direct Laser Writing And Electroless Metal Deposition, Amir Tal
Electronic Theses and Dissertations
Three-dimensional (3D) metal photonic crystals (MPCs) can exhibit interesting electromagnetic properties such as ultra-wide photonic or "plasmonic" band gaps, selectively tailored thermal emission, extrinsically modified absorption, and negative refractive index. Yet, optical-wavelength 3D MPCs remain relatively unexplored due to the challenges posed by their fabrication. This work explores the use of multi-photon direct laser writing (DLW) coupled with electroless metallization as a means for preparing MPCs. Multi-photon DLW was used to prepare polymeric photonic crystal (PC) templates having a targeted micron-scale structure and form. MPCs were then created by metallizing the polymeric PCs via wet-chemical electroless deposition. The electromagnetic properties …
Fluorescence Imaging Study Of Free And Impinging Supersonic Jets: Jet Structure And Turbulent Transition, Jennifer Ann Inman
Fluorescence Imaging Study Of Free And Impinging Supersonic Jets: Jet Structure And Turbulent Transition, Jennifer Ann Inman
Dissertations, Theses, and Masters Projects
A series of experiments into the behavior of underexpanded jet flows has been conducted at NASA Langley Research Center. This work was conducted in support of the Return to Flight effort following the loss of the Columbia. The tests involved simulating flow through a hypothetical breach in the leading edge of the Space Shuttle Orbiter along its reentry trajectory, with the goal of generating a data set with which other researchers can test and validate computational modeling tools. Two nozzles supplied with high-pressure gas were used to generate axisymmetric underexpanded jets exhausting into a low-pressure chamber. These nozzles had exit …
First-Principles Calculations Of Electric Field Gradients In Complex Perovskites, Dandan Mao
First-Principles Calculations Of Electric Field Gradients In Complex Perovskites, Dandan Mao
Dissertations, Theses, and Masters Projects
Various experimental and theoretical work indicate that the local structure and chemical ordering play a crucial role in the different physical behaviors of lead-based complex ferroelectrics with the ABO 3 perovskite structure. First-principles linearized augmented plane wave (LAPW) with the local orbital extension method within local density approximation (LDA) are performed on structural models of Pb(Zr1/2Ti1/2 )O3 (PZT), Pb(Sc1/2Ta1/2)O3 (PST), Pb(Sc2/3W1/3)O3 (PSW), and Pb(Mg 1/3Nb2/3)O3 (PMN) to calculate electric field gradients (EFGs). In order to simulate these disordered alloys, various structural models were constructed with different imposed chemical orderings and symmetries. Calculations were carried out as a function of B-site …
Effects Of Molecular Motion On Deuteron Magic Angle Spinning Nmr Spectra, Yuanyuan Huang
Effects Of Molecular Motion On Deuteron Magic Angle Spinning Nmr Spectra, Yuanyuan Huang
Dissertations, Theses, and Masters Projects
Solid state deuteron NMR experiments, especially magic angle spinning (MAS) and off-magic angle spinning (OMAS), are developed to explore dynamical systems. A theoretical discussion of interactions relevant for spin-1 nuclei is presented. Practical aspects of MAS/OMAS experiments are described an detail. The dominant quadrupolar coupling interaction in deuteron NMR has been simulated and the effects of multiple-frame molecular motions on MAS/OMAS spectra are taken into account in this calculation. Effects of chemical shift anisotropy are also simulated, and shown to be small under conditions of rapid sample spinning.;Two numerical methods, direct integration and an efficient simulation routine based on Floquet …
Spatial Beam Shaping Of High-Power Ultrashort Laser Pulses, Shuyan Zhang
Spatial Beam Shaping Of High-Power Ultrashort Laser Pulses, Shuyan Zhang
Dissertations, Theses, and Masters Projects
This thesis presents both theoretical and experimental studies of a diffractive beam shaping system for ultrashort high-power laser pulses.;A theoretical model is developed to simulate the reshaped intensity profiles for a 100-fs pulse with various energy levels. Both temporal evolution and spatial intensity distribution of the pulse at the target plane of the beam shaping system are calculated. Numerical simulation shows that after passing through the beam shaping system, the pulse front is significantly curved due to the propagation time delay, and the pulse duration time through the target plane is broadened because of the group velocity dispersion. However, for …
Magneto-Optical Imaging Of Superconducting Mgb2 Thin Films, Stephanie Maria Hummert
Magneto-Optical Imaging Of Superconducting Mgb2 Thin Films, Stephanie Maria Hummert
Dissertations, Theses, and Masters Projects
No abstract provided.
Investigating Student Understanding Of Sound As A Longitudinal Wave, Earl C. Coombs
Investigating Student Understanding Of Sound As A Longitudinal Wave, Earl C. Coombs
Electronic Theses and Dissertations
The field of physics education research (PER) has highlighted the discrepancy between what is taught during traditional instruction in physics, and what students understand afterward. PER has also provided alternatives to traditional instruction that are research-based and have been shown to be more effective in bringing students’ level of understanding of physics more in line with that of the scientific community. One topic that has received attention is the propagation of sound. We confirmed that students in the introductory algebra-based and calculus-based physics courses at the University of Maine have difficulties with sound propagation similar to those documented by others. …
Measurement Of The Branching Fraction For The Decay Neutral Kaon(Long) Going To Pion-Antipion-Positron-Electron In The High M(Pi-Pi) Invariant Mass Region, Joshua J. Moss
Dissertations, Theses, and Masters Projects
A measurement of the branching fraction for the rare decay K0L → pi+pi-e +e- was performed using data collected from experiment E871 which ran at the AGS of Brookhaven National Laboratory. Analysis of the data revealed 27.7 +/- 7.4 signal events in the signal region, 0.4905 GeV < Mpipiee < 0.505 GeV together with 13.3 +/- 3.7 background events. The branching fractions of ( 8.5+/-2.3stat +/-1.0sys ) x 10-6 using the phenomenological model acceptance and ( 2.3+/-0.6stat +/-0.3sys ) x 10-6 using the chiral perturbation model represent the first measurements for K0L → pi+pi-e +e- in the dipion invariant mass region 0.475 GeV < Mpipi < 0.497 GeV. These results support the prediction of chiral perturbation theory rather than that of the phenomenological model.
Magnetization Dynamics And Anisotropy In Ferromagnetic/Antiferromagnetic Ni/Nio Bilayers, Andreas Petersen
Magnetization Dynamics And Anisotropy In Ferromagnetic/Antiferromagnetic Ni/Nio Bilayers, Andreas Petersen
Dissertations, Theses, and Masters Projects
No abstract provided.
Electron Beam Characterization Of Carbon Nanostructures, Eric Samuel Mandell
Electron Beam Characterization Of Carbon Nanostructures, Eric Samuel Mandell
Doctoral Dissertations
"Atom-thick carbon nanostructures represent a class of novel materials that are of interest to those studying carbon's role in fossil fuel, hydrogen storage, scaled-down electronics, and other nanotechnology. Electron microscope images of "edge-on" graphene sheets show linear image features due to the projected potential of the sheets. Here, intensity profiles along these linear features can measure the curvature of the sheet, as well as the shape of the sheet (i.e. hexagonal, triangular). Also, electron diffraction powder profiles calculated for triangular graphene sheet shapes show a broadening of the low frequency edge of diffraction rings, in comparison to those calculated for …
Investigation Of The Reflective Properties Of A Left-Handed Metamaterial, Amanda Durham
Investigation Of The Reflective Properties Of A Left-Handed Metamaterial, Amanda Durham
Browse all Theses and Dissertations
The purpose of this project is to investigate the reflective properties of a left-handed metamaterial (LHM) through the use of a finite element analysis software called FEMLAB. In the 1960's, V. Veselago theorized that a material with negative permeability and negative permittivity has a negative index of refraction. In 2000, such a metamaterial was built and demonstrated at microwave frequencies. Previous work had focused on the transmission properties of the metamaterial. In our work, the reflected wave was examined for a LHM subject to an incident transverse electric wave. The different generalizations, first proposed by Veselago, of the Fresnel and …
Fabrication And Study Of Zno Micro- And Nanostructures, Monica Morales-Masis
Fabrication And Study Of Zno Micro- And Nanostructures, Monica Morales-Masis
Browse all Theses and Dissertations
ZnO micro-structures and nano-structures have been grown on two types of substrate by reacting condensed Zn vapor with oxygen. The source material was either pure zinc powder or zinc acetate which was either evaporated or decomposed. This was done in the temperature range 500 C to 650 C, in a flowing Ar plus oxygen ambient at atmospheric pressure. Variations in the carrier gas composition, gas flow rate and the position of the substrate in the furnace were found to control the formation and the morphology of the nanostructures. Scanning electron microscopy images of samples grown from a Zn powder source …
Evanescent Microwave Characterization Of Carbon Nanotube Films Grown On Silicon Carbide Substrate, Kineshma Munbodh
Evanescent Microwave Characterization Of Carbon Nanotube Films Grown On Silicon Carbide Substrate, Kineshma Munbodh
Browse all Theses and Dissertations
The electromagnetic characterization of carbon nanotube films (CNT) grown by the surface decomposition of silicon carbide (SiC) has been performed. The CNT films formed on the carbon and silicon terminated face of the SiC substrate were uncapped by an annealing process at a temperature of 4000 C with dwelling time up to 60 minutes in oxygen or carbon dioxide atmosphere. X-Y scans of the quality factor were used to deduce the local conductive properties of the films measured by evanescent microwave microscopy. Real and imaginary permittivity values, as determined by these electromagnetic measurements, provided valuable information for future field emission …
Comparative Investigation Of Dosimetric Tools In Imrt, Aaron Nicholas Garcia
Comparative Investigation Of Dosimetric Tools In Imrt, Aaron Nicholas Garcia
Browse all Theses and Dissertations
Verification of the isodose distribution delivered to the planned tumor volume is required for quality assurance in the clinic. Verification in this context means ensuring that the actual dose delivered to a volume matches the dose that a computerized planning system intended that volume to receive. The computerized planning is performed by a Computerized Medical Systems (CMS) Intensity Modulated Radiation Therapy (IMRT) plan. Two methods of measuring the delivered dose are film dosimetry and diode dosimetry. This project will compare the relative isodose distribution profiles of film dosimetry and MapCheck (Sun Nuclear Corporation, a diode-based dosimetry system) to the relative …
Fabrication Of Silver Nanoparticles By Solution Phase Method And Physical Characterization Of Their Arrays, Jaesung Oh
Fabrication Of Silver Nanoparticles By Solution Phase Method And Physical Characterization Of Their Arrays, Jaesung Oh
Browse all Theses and Dissertations
Synthesis of silver nanostructures has been an active research area for many decades because of their importance in biological sensing, imaging, electronics, optoelectronics and catalysis. In particular, much effort has been devoted to the controlled synthesis of silver nanowires because of their potential use as interconnects or active components in fabricating nanoscale devices. The solution phase method is used here to form Ag nanoparticles by reducing silver nitrate with ethylene glycol heated to 160°C. The additional presence of polyvinyl pyrrolidone plays a role of stabilizer to prevent an agglomeration and/or a capping agent to produce highly anisotropic nanowires. Silver nanoparticles …
Polarization Reversal In Potassium Titanyl Phosphate, William D. Mitchell
Polarization Reversal In Potassium Titanyl Phosphate, William D. Mitchell
Browse all Theses and Dissertations
Polarization reversal in both hydrothermal and flux grown potassium titanyl phosphate was studied using square pulses at room temperature from 1600 V/mm to 5000 V/mm. Maximum switching current and inverse switching time data is compared to the ferroelectric polarization reversal model developed by Fatuzzo and Merz in the last century. Room temperature calculation of spontaneous polarization is reported and compared to that of potassium titanyl phosphate in the literature.
Quantum Dot Photolithography, Raghuveer Reddy Gadipalli
Quantum Dot Photolithography, Raghuveer Reddy Gadipalli
Doctoral Dissertations
"This dissertation presents a simple method for the photolithographic patterning of silica hydrogel monoliths and planar substrates with quantum dots and inorganic semiconductor nanoparticles. We developed a method for surface patterning and bulk (3D) patterning of silica hydrogel monoliths and surface patterning of planar substrates with CdS, CdSe, PbS and PbSe quantum dots using infrared light, ultraviolet light, X-rays, and multi-photon ionization radiation. Precursor combinations were prepared which can readily dissociate with IR, UV, X-rays, and multi-photon ionization radiation. Different capping agents were used for improving quantum dot size distribution. The luminescence quantum yield of the composites can be increased …