Current Search: Electromagnetic theory (x)
View All Items
(1 - 6 of 6)
- Title
- Electromagnetic field emissions from underwater power cables.
- Creator
- DiBiasio, Christopher, Dhanak, Manhar R., Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
This study is performed as a partial aid to a larger study that aims to determine if electromagnetic fields produced by underwater power cables have any effect on marine species. In this study, a new numerical method for calculating magnetic fields around subsea power cables is presented and tested. The numerical method is derived from electromagnetic theory, and the program, Matlab, is implemented in order to run the simulations. The Matlab code is validated by performing a series of tests...
Show moreThis study is performed as a partial aid to a larger study that aims to determine if electromagnetic fields produced by underwater power cables have any effect on marine species. In this study, a new numerical method for calculating magnetic fields around subsea power cables is presented and tested. The numerical method is derived from electromagnetic theory, and the program, Matlab, is implemented in order to run the simulations. The Matlab code is validated by performing a series of tests in which the theoretical code is compared with other previously validated magnetic field solvers. Three main tests are carried out; two of these tests are physical and involve the use of a magnetometer, and the third is numerical and compares the code with another numerical model known as Ansys. The data produced by the Matlab code remains consistent with the measured values from both the magnetometer and the Ansys program; thus, the code is considered valid. The validated Matlab code can then be implemented into other parts of the study in order to plot the magnetic field around a specific power cable.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00004277, http://purl.flvc.org/fau/fd/FA00004277
- Subject Headings
- DIstributed generation of electric power, Electromagnetic interference, Electromagnetic theory, Ocean energy resources -- Environmental aspects
- Format
- Document (PDF)
- Title
- Application of MoM: Scattering calculations using condition number.
- Creator
- Zhuang, Zhijun., Florida Atlantic University, Bagby, Jonathan S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Computational accuracy is widely recognized as a critical issue in applied electromagnetics. Increasing computational power is being applied to solve more complex electromagnetic systems with an emphasis on computational accuracy. The work of this thesis is focused on the implementation of Method of Moments (MoM) to integral equation formulations. The goal of this effort is to use what is known as condition number, and, a heuristic rule-of-thumb is applied to investigate the computational...
Show moreComputational accuracy is widely recognized as a critical issue in applied electromagnetics. Increasing computational power is being applied to solve more complex electromagnetic systems with an emphasis on computational accuracy. The work of this thesis is focused on the implementation of Method of Moments (MoM) to integral equation formulations. The goal of this effort is to use what is known as condition number, and, a heuristic rule-of-thumb is applied to investigate the computational accuracy of MoM in numerical electromagnetics. Other possible applications of condition number of the MoM matrix are also indicated.
Show less - Date Issued
- 1999
- PURL
- http://purl.flvc.org/fcla/dt/15719
- Subject Headings
- Electromagnetism, Moments method (Statistics), Electromagnetic theory, Integral equations--Numerical solutions
- Format
- Document (PDF)
- Title
- Size distribution of polymer-coated magnetite nanoparticles.
- Creator
- Gopman, Daniel B., Harriet L. Wilkes Honors College
- Abstract/Description
-
A method for estimating the size distribution of magnetite nanoparticles from their magnetic properties is presented. The 10 nm diameter particles were coated with poly(acrylic) acid and prepared as a water-based suspension. A vacuum-dried sample was placed in a transmission electron microscope (TEM) so that the physical sizes of the particles could be estimated. The particle magnetization was measured by a superconducting quantum interference device (SQUID) in magnetic fields up to 25...
Show moreA method for estimating the size distribution of magnetite nanoparticles from their magnetic properties is presented. The 10 nm diameter particles were coated with poly(acrylic) acid and prepared as a water-based suspension. A vacuum-dried sample was placed in a transmission electron microscope (TEM) so that the physical sizes of the particles could be estimated. The particle magnetization was measured by a superconducting quantum interference device (SQUID) in magnetic fields up to 25 kiloOersted and temperatures ranging from 5 to 370 Kelvin. The magnetic moments in the sample were estimated by fitting those measurements to a Langevin magnetization model, weighted by a log-normal distribution with unknown parameters.The best-fit procedure yielded particle volumes smaller than those observed by transmission electron microscopy, suggesting the existence of a magnetically inactive layer of atoms. In addition, our particles exhibited stronger spin-wave behavior than expected for particles of similar size, as evidenced by the lower saturation magnetization and higher Bloch coefficient.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/FAU/77669
- Subject Headings
- Particles (Nuclear physics), Electromagnetic theory, Particle size determination
- Format
- Document (PDF)
- Title
- Plane-Wave Scattering of a Periodic Corrugated Cylinder.
- Creator
- Garcia, Samuel, Bagby, Jonathan Dr., Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
In this dissertation, a novel approach to modeling the scattered field of a periodic corrugated cylinder, from an oblique incident planewave, is presented. The approach utilizes radial waveguide approximations for fields within the corrugations, which are point matched to approximated scattered fields outside of the corrugation to solve for the expansion coefficients. The point matching is done with TMz and TEz modes simultaneously, allowing for hybrid modes to exist. The derivation of the...
Show moreIn this dissertation, a novel approach to modeling the scattered field of a periodic corrugated cylinder, from an oblique incident planewave, is presented. The approach utilizes radial waveguide approximations for fields within the corrugations, which are point matched to approximated scattered fields outside of the corrugation to solve for the expansion coefficients. The point matching is done with TMz and TEz modes simultaneously, allowing for hybrid modes to exist. The derivation of the fields and boundary conditions used are discussed in detail. Axial and radial propagating modes for the scattered fields are derived and discussed. Close treatment is given to field equations summation truncation and conversion to matrix form, for numerical computing. A detailed account of the modeling approach using Mathematica® and NCAlgebra for the noncommutative algebra, involved in solving for the expansion coefficients, are also given. The modeling techniques offered provide a full description and prediction of the scattered field of a periodic corrugated cylinder. The model is configured to approximate a smooth cylinder, which is then compared against that of a textbook standard smooth cylinder. The methodology and analysis applied in this research provide a solution for computational electromagnetics, RF communications, Radar systems and the like, for the design, development, and analysis of such systems. Through the rapid modeling techniques developed in this research, early knowledge discovery can be made allowing for better more effective decision making to be made early in the design and investigation process of an RF project.
Show less - Date Issued
- 2017
- PURL
- http://purl.flvc.org/fau/fd/FA00004819
- Subject Headings
- Diffractive scattering., Radio frequency integrated circuits., Electromagnetic waves--Mathematical models., Electromagnetic waves--Diffraction., Electromagnetic waves--Scattering., Fourier transformations., Electromagnetic theory--Mathematical models.
- Format
- Document (PDF)
- Title
- Plane-Wave Scattering of a Periodic Corrugated Cylinder.
- Creator
- Garcia, Samuel, Bagby, Jonathan, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
In this dissertation, a novel approach to modeling the scattered field of a periodic corrugated cylinder, from an oblique incident planewave, is presented. The approach utilizes radial waveguide approximations for fields within the corrugations, which are point matched to approximated scattered fields outside of the corrugation to solve for the expansion coefficients. The point matching is done with TMz and TEz modes simultaneously, allowing for hybrid modes to exist. The derivation of the...
Show moreIn this dissertation, a novel approach to modeling the scattered field of a periodic corrugated cylinder, from an oblique incident planewave, is presented. The approach utilizes radial waveguide approximations for fields within the corrugations, which are point matched to approximated scattered fields outside of the corrugation to solve for the expansion coefficients. The point matching is done with TMz and TEz modes simultaneously, allowing for hybrid modes to exist. The derivation of the fields and boundary conditions used are discussed in detail. Axial and radial propagating modes for the scattered fields are derived and discussed. Close treatment is given to field equations summation truncation and conversion to matrix form, for numerical computing. A detailed account of the modeling approach using Mathematica® and NCAlgebra for the noncommutative algebra, involved in solving for the expansion coefficients, are also given. The modeling techniques offered provide a full description and prediction of the scattered field of a periodic corrugated cylinder. The model is configured to approximate a smooth cylinder, which is then compared against that of a textbook standard smooth cylinder. The methodology and analysis applied in this research provide a solution for computational electromagnetics, RF communications, Radar systems and the like, for the design, development, and analysis of such systems. Through the rapid modeling techniques developed in this research, early knowledge discovery can be made allowing for better more effective decision making to be made early in the design and investigation process of an RF project.
Show less - Date Issued
- 2017
- PURL
- http://purl.flvc.org/fau/fd/FA00004819a
- Subject Headings
- Diffractive scattering., Radio frequency integrated circuits., Electromagnetic waves--Mathematical models., Electromagnetic waves--Diffraction., Electromagnetic waves--Scattering., Fourier transformations., Electromagnetic theory--Mathematical models.
- Format
- Document (PDF)
- Title
- Influence of the boundaries on the acoustic scattering by a submerged target.
- Creator
- Charmes, Emmanuel., Florida Atlantic University, Beaujean, Pierre-Philippe, Cuschieri, Joseph M.
- Abstract/Description
-
In shallow water or fluid half-space, the acoustic scattering from a target is significantly different from that of an unbounded medium, due to the multiple reflections occurring between the target and the boundaries. The purpose of this thesis is to investigate the influence of the boundaries on the acoustic scattering of a rigid sphere by means of a superposition method. A minimum number of point sources necessary to accurately model the scattered field is determined in the case of a free...
Show moreIn shallow water or fluid half-space, the acoustic scattering from a target is significantly different from that of an unbounded medium, due to the multiple reflections occurring between the target and the boundaries. The purpose of this thesis is to investigate the influence of the boundaries on the acoustic scattering of a rigid sphere by means of a superposition method. A minimum number of point sources necessary to accurately model the scattered field is determined in the case of a free medium, a fluid half-space and a waveguide. The free field symmetry vanishes due to the presence of boundaries and, at particular frequencies or scatterer depths, a significant change in the magnitude and spatial distribution of the scattered field occur. In an unbounded medium or fluid half space, the superposition method is shown to give similar results to analytical formulations found in the literature, provided enough point sources are used.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/13211
- Subject Headings
- Electromagnetic waves--Scattering, Acoustical engineering, Sound-waves--Measurement, Wave-motion, Theory of
- Format
- Document (PDF)
