Current Search:  Scattering Physics (x)

View All Items

  • CSV Spreadsheet
(1 - 7 of 7)
TM MODE SCATTERING BY A GLASS-ENCLOSED PLASMA CYLINDER
Title
TM MODE SCATTERING BY A GLASS-ENCLOSED PLASMA CYLINDER.
Creator
QUINNELL, ROBERT DOUGLASS., Florida Atlantic University
Abstract/Description
Expressions are developed for the near and far field angular intensity distributions of TM mode scattering of a plane wave by a glass-enclosed plasma cylinder. Numerical computations for a simple collisionless plasma model are made in order to study the effect of the free electron density structure on intensity distributions. The inverse problem is briefly considered.
Date Issued
1973
PURL
http://purl.flvc.org/fcla/dt/13560
Subject Headings
Scattering (Physics)
Format
Document (PDF)
Application of QKKR method to complex crystals
Title
Application of QKKR method to complex crystals.
Creator
Wang, Yang, Florida Atlantic University, Faulkner, J. Samuel
Abstract/Description
The QKKR method is a recently invented band theory with remarkable advantages of fast computational speed and no special requirements on the one electron potential. It has been successfully applied to the band structure calculation for simple crystals. A program for QKKR band theory calculations for complex crystals (more than one atom per unit cell) is developed and applied to PdH. It is shown that, compared with the KKR method, the QKKR method is more efficient and yields very accurate...
Show moreThe QKKR method is a recently invented band theory with remarkable advantages of fast computational speed and no special requirements on the one electron potential. It has been successfully applied to the band structure calculation for simple crystals. A program for QKKR band theory calculations for complex crystals (more than one atom per unit cell) is developed and applied to PdH. It is shown that, compared with the KKR method, the QKKR method is more efficient and yields very accurate results in the range of energies in which we are interested. Unlike other band theories, the QKKR requires the expansion of a three dimensional step function in real spherical harmonics. A general method for evaluating this expansion is established in this thesis.
Show less
Date Issued
1989
PURL
http://purl.flvc.org/fcla/dt/14529
Subject Headings
Crystallography, Mathematical, Multiple scattering (Physics)
Format
Document (PDF)
Convergence properties of the screened Korringa-Kohn-Rostoker method
Title
Convergence properties of the screened Korringa-Kohn-Rostoker method.
Creator
Moghadam, Nassrin Y., Florida Atlantic University, Faulkner, J. Samuel
Abstract/Description
Within the Green's function approach to the multiple scattering theory, we present a different formalism for the screened Korringa-Kohn-Rostoker (KKR) scheme. In addition, we investigate the convergence properties of the screened KKR by performing total energy and density of states calculations for a fcc copper. Finally, we introduce a new approach to (near) tight binding calculations of the screened tau-matrix that yields total energies within the desired accuracy.
Date Issued
1997
PURL
http://purl.flvc.org/fcla/dt/15370
Subject Headings
Multiple scattering (Physics), Electronic structure
Format
Document (PDF)
Target signature for a periodic structure using a low-frequency broadband side-scan simulator
Title
Target signature for a periodic structure using a low-frequency broadband side-scan simulator.
Creator
Dietz, Jerrold Edward Gilbert., Florida Atlantic University, LeBlanc, Lester R.
Abstract/Description
Many acoustic targets of interest contain features that are periodic in space. This thesis demonstrates that a chirp waveform, 2 kHz to 12 kHz, can detect repetitive structures with periods in the range of 0.125 m to 0.75 m. As aspect angle increases from 0 deg to 90 deg, a frequency shift in the range of 830 Hz to 4800 Hz will occur as the period decreases from 0.75 to 0.125 m. It follows that, spectral analysis can aid in target identification. A sonar propagation model has been developed...
Show moreMany acoustic targets of interest contain features that are periodic in space. This thesis demonstrates that a chirp waveform, 2 kHz to 12 kHz, can detect repetitive structures with periods in the range of 0.125 m to 0.75 m. As aspect angle increases from 0 deg to 90 deg, a frequency shift in the range of 830 Hz to 4800 Hz will occur as the period decreases from 0.75 to 0.125 m. It follows that, spectral analysis can aid in target identification. A sonar propagation model has been developed to simulate the acoustic backscattered energy of a target with periodic characteristics in the presence of seafloor scattering. Examining the spectral components, with appropriate time gating, can achieve a gain of 7 dB at 3100 m.
Show less
Date Issued
2001
PURL
http://purl.flvc.org/fcla/dt/12788
Subject Headings
Sidescan sonar, Underwater acoustics, Scattering (Physics)
Format
Document (PDF)
Exploring the electromagnetics of millimeter-wave through terahertz spectrum: de novo studies vis-à-vis materials science, biomedical applications and wireless communication
Title
Exploring the electromagnetics of millimeter-wave through terahertz spectrum: de novo studies vis-à-vis materials science, biomedical applications and wireless communication.
Creator
Sharma, Bharti, Neelakanta, Perambur S., Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description
The present research is a targeted endeavor to study the underlying characteristics and novel applications of millimeter (mm) wave through terahertz (THz) spectrum of electromagnetic (EM) energy. Focused thereof are the following specific tasks broadly considered pertinent to the said EM spectral range: (i) To elucidate the material characteristics vis-à-vis the interaction with EM energy at the test frequencies; (ii) to identify biomedical applications based on the material characteristics...
Show moreThe present research is a targeted endeavor to study the underlying characteristics and novel applications of millimeter (mm) wave through terahertz (THz) spectrum of electromagnetic (EM) energy. Focused thereof are the following specific tasks broadly considered pertinent to the said EM spectral range: (i) To elucidate the material characteristics vis-à-vis the interaction with EM energy at the test frequencies; (ii) to identify biomedical applications based on the material characteristics studied and applied to biomedia; and (iii) to model the wireless communication channels supporting EM waves at the test frequency bands of interest. Commensurate with the scope as above, the objectives of the research are as follows:
Show less
Date Issued
2014
PURL
http://purl.flvc.org/fau/fd/FA00004330, http://purl.flvc.org/fau/fd/FA00004330
Subject Headings
Electromagnetic waves -- Scattering, Pattern recognition systems, Scattering (Physics), Terahertz technology, Wireless communication systems
Format
Document (PDF)
Experimental imaging performance evaluation for alternate configurations of undersea pulsed laser serial imagers
Title
Experimental imaging performance evaluation for alternate configurations of undersea pulsed laser serial imagers.
Creator
Dalgleish, Fraser R., Vuorenkoski, Anni K., Nootz, G., Ouyang, Bing, Caimi, F. M.
Date Issued
2011
PURL
http://purl.flvc.org/FCLA/DT/3340796
Subject Headings
Electrooptics, Underwater imaging systems, Image Quality, Scattering (Physics), Lasers
Format
Document (PDF)
Examination of the R-process in accretion-induced collapse (AIC)
Title
Examination of the R-process in accretion-induced collapse (AIC).
Creator
Davis, Daryl C., Florida Atlantic University, Bruenn, Stephen W.
Abstract/Description
This work is a simulation of the Accretion-Induced Collapse of a 1.37 solar mass white dwarf into a neutron star and the subsequent generation of a neutrino-driven wind, with an examination as to whether the event is a candidate for r-process nucleosynthesis. The simulation utilizes a new radiation hydrodynamic code, RadHyd, to model the AIC event. We examine the process of Accretion-Induced Collapse utilizing two sets of neutrino-scattering and absorption rates: The first, and simpler of the...
Show moreThis work is a simulation of the Accretion-Induced Collapse of a 1.37 solar mass white dwarf into a neutron star and the subsequent generation of a neutrino-driven wind, with an examination as to whether the event is a candidate for r-process nucleosynthesis. The simulation utilizes a new radiation hydrodynamic code, RadHyd, to model the AIC event. We examine the process of Accretion-Induced Collapse utilizing two sets of neutrino-scattering and absorption rates: The first, and simpler of the two has been in use since they were first introduced in 1985. The second includes a more accurate implementation of neutrino-nucleon scattering and nucleon bremsstrahlung. The improved nue - nue-nucleon scattering rate now permits energy to be exchanged between neutrinos and matter by this process, and is therefore important for the numu's and nutau's, as their only channels for exchanging energy in the standard rates was by the relatively weak NES and pair processes. Neutrino-nucleon bremmsstrahlung is also important for numu's and nutau's as this opens another channel (beside pair process) for their production. Both simulations show a neutrino-driven wind being generated after core bounce and shock propagation. We examine the conditions in these winds to ascertain whether the requisite conditions are attained for an r-process. In neither case are these achieved during the time of the simulations (i.e. 2 seconds). However, these simulations need to be carried out at least an order of magnitude longer before firm conclusions can be drawn about the applicability of this site for the r-process.
Show less
Date Issued
2005
PURL
http://purl.flvc.org/fcla/dt/12136
Subject Headings
Nuclear astrophysics--Research, Scattering (Physics), Nucleon-nucleon scattering--Research, Field theory (Physics), Stellar winds
Format
Document (PDF)