| Algorithm Development for the Two-Fluid Plasma Model |
17-Feb-2009 |
19 pages |
| Authors:
Uri Shumlak; WASHINGTON UNIV SEATTLE AEROSPACE AND ENERGETICS RESEARCH PROGRAM
|
 | A new algorithm is developed based on the two-fluid plasma model that is more physically accurate and capable than MHD models. The algorithm uses high-order spatial and temporal accuracy to simulate time-dependent, three-dimensional plasma phenomena. High-order spatial accuracy is accomplished using a discontinuous Galerkin finite element method that has provided up to 16th order accuracy. The temporal evolution is advanced using a 3rd order Runge-Kutta method. The numerical fluxes are ... |
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| Safe Acceptable Standoff Distances for Body Wearable Antennas |
Dec-2008 |
9 pages |
| Authors:
George Palafox; Waliul Mizan; ARMY COMMUNICATIONS-ELECTRONICS RESEARCH DEVELOPMENT AND ENG CTR FT MONMOUTH NJ
|
| Soldier Manpack radios for programs such as Future Warrior Technology Integration (FWTI), Land Warrior (LW) , and JTRS Handheld Manpack and Small Form Fit (HMS) use standard whip antennas which can be as large as a meter in height. During combat operations, the whip antenna can become entangled, damaged or destroyed, causing a degradation or loss of communications. In addition to the antenna's size, whip antennas present electrical challenges in ... |
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| Analysis of Curved Frequency Selective Surfaces |
16-May-2008 |
76 pages |
| Authors:
Zvonimir Sipus; Sinisa Skokic; Marko Bosiljevac; ZAGREB UNIV (CROATIA)
|
| This report results from a contract tasking University of Zagreb as follows: 1. Formulation of the problem. First period of the project is reserved for making a detailed formulation of the problem. Our starting point will be the existing MoM based program for analyzing patch arrays on placed on cylindrical and spherical structures (programs CyMPA and SMiPA that are developed under the projects F61775-99-WE040 and F61775-01-WE024). The main difference between ... |
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| Contrast Enhancement for Thermal Acoustic Breast Cancer Imaging via Resonant Stimulation |
01-Mar-2008 |
30 pages |
| Authors:
Jian Li; Mark Sheplak; Lou Cattafesta; Henry Zmuda; Huabei Jiang; Manuel Arreola; FLORIDA UNIV GAINESVILLE
|
| This research plans to develop enhanced contrast thermal acoustic imaging (TAI) technology for the detection of breast cancer by combining amplitude-modulated (AM) electromagnetic (EM) field excitation resonant acoustic scattering and advanced signal processing techniques. While EM-induced TAI possesses great promise, the thermal acoustic signals tend to be weak However when the tumor is excited into resonance via EM stimulation the effective acoustic scattering cross-section may increase by a factor in ... |
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| Computational Electromagnetics |
25 FEB 2008 |
10 pages |
| Authors:
Oscar P. Bruno; MICHELSON SCIENCE CENTRE/CALTECH PASADENA CA
|
| The Objectives are as follows: 1) High-frequency integral equations: Multiple-scattering/ shadowing interactions; 2) Periodic and random surfaces and structures; 3) Canonical Integration: Edge scattering; 4) Canonical Integration: High Frequency; 5) Geometry representation and solution of challenging real-world problems. |
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| Eliminating Space Debris: Applied Technology and Policy Prescriptions, Fall 2007 - Project 07-02 |
Jan-2008 |
139 pages |
| Authors:
Kevin Johnson; Hudson; John G II; Stephanie Silva; Jared Brower; Stehanie Cook; Edward Dae; Josh Koch; Miller Miller; STRATEGIC COMMAND OMAHA NE GLOBAL INNOVATION AND STRATEGY CENTER
|
| Communications, global commerce and national defense are highly dependent on satellite constellations. This report details how space debris threatens valuable space-based technology essential to these critical areas. Objects in lower earth orbit (LEO) pose the greatest immediate threat to space-based assets. This paper focuses on all sizes of debris found in LEO. What follows is a comprehensive analysis of the problem of space debris, specifically targeting policies that facilitate debris ... |
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| Standardized UXO Technology Demonstration Site Mine Grid Scoring Record No. 838 |
OCT 2007 |
40 pages |
| Authors:
Rick Fling; Christina McClung; William Burch; Patrick McDonnell; Dennis Teefy; ABERDEEN TEST CENTER MD
|
| This Scoring Record documents the efforts of NAEVA Geophysics, Inc., to detect and discriminate inert unexploded ordnance (UXO) utilizing the APG Standardized UXO Technology Demonstration Site Mine Grid. This Scoring Record was coordinated by Dennis Teefy and the Standardized UXO Technology Demonstration Site Scoring Committee. Organizations on the committee include the U.S. Army Corps of Engineers, the Environmental Security Technology Certification Program, the Strategic Environmental Research and Development Program, the ... |
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| High-Order Accurate Time-Domain Electromagnetics and RCS Prediction for Dynamic and Uncertain Scatters |
30 SEP 2007 |
24 pages |
| Authors:
Jan S. Hesthaven; BROWN UNIV PROVIDENCE RI DIV OF APPLIED MATHEMATICS
|
| In this project we have pursued the development of computational ways of quantifying the impact of uncertainties on RCS computation. We present a systematic, accurate, and efficient way of addressing such problem, essentially enabling one to compute with an ensample of data and, subsequently, obtain a full space-time ensample of solutions with an associated probability density. The uncertainties can be present in the sources, the materia1s, or the geometries. |
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| Sea Clutter Generation and Target Detection |
JUL 2007 |
26 pages |
| Authors:
Stefano M. Canta; Danilo Erricolo; ILLINOIS UNIV AT CHICAGO CIRCLE COLL OF ENGINEERING
|
| Propagation model for the electromagnetic field that accounts for the clutter and metallic objects in the sea. Computationally fast, and the complete work will include electromagnetic propagation models and vector antennas. |
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| Enhanced Electromagnetic Tagging for Embedded Tracking of Munitions and Ordnance During Future Remediation Efforts. Revision 2 |
JUN 2007 |
219 pages |
| Authors:
Keith A. Shubert; R. J. Davis; T. J. Barnum; B. D. Balaban; R. L. Amdor; B. J. Sikorski; T. J. Peters; J. W. Griffin; BATTELLE COLUMBUS OPERATIONS OH
|
| The program's objective was to investigate means of tagging ordnance items before they are fired or launched and thereby allow a more efficient means for locating unexploded ordnance (UXO) while maintaining very low false alarm rates. Five candidate munitions were selected as being representative of meeting the criteria. Physical mounting options for these five candidate munitions are documented in this report. After investigating radio frequency identification (RFID) tags, Battelle concluded ... |
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| Basis of Ionospheric Modification by High-Frequency Waves |
JUN 2007 |
21 pages |
| Authors:
S. P. Kuo; POLYTECHNIC UNIV BROOKLYN NY DEPT OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCE
|
| The requirements of achieving ionospheric modification by ground-transmitted HF heating waves are discussed. The directly relevant processes including linear mode conversion and parametric instabilities are explained physically. The nonline & Schrodinger equation for Langmuir waves is reviewed and the initial conditions of two types of nonlinear solutions are discussed; from which the criterion for Langmuir soliton generation is pointed out. |
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| Advanced Polarimetric Concepts - Part 1 (Polarimetric Target Description, Speckle filtering and Decomposition Theorems) |
01 FEB 2007 |
31 pages |
| Authors:
Eric Pottier; Jong-Sen Lee; Laurent Ferro-Famil; UNIVERSITE DE RENNES 1 (FRANCE) INSTITUT ELECTRONIQUE TELECOMMUNICATION DE RENNES (IETR)
|
| There is currently a great deal of interest in the use of polarimetry for radar remote sensing. In this context, different and important objectives are to classify Earth terrain components within a fully polarimetric SAR image and then extract physical information from the observed scattering of microwaves by surface and volume structures. The most important observable measured by such radar systems is the 3x3-coherency matrix. This matrix accounts for local ... |
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| Possible Gravitational Anomalies in Quantum Materials. Phase 2: Experiment Assembly, Qualification and Test Results |
FEB 2007 |
56 pages |
| Authors:
M. Tajmar; AUSTRIAN RESEARCH CENTERS SEIBERSDORF RESEARCH (ARCS) SEIBERSDORF (AUSTRIA)
|
| The author recently published a paper, suggesting for the first time that a reported disagreement between experimental measurements and theoretical predictions for the magnetic field in rotating superconductors might arise from an anomalous high-order gravitomagnetic contribution (also known as frame dragging or Lense-Thirring effect). In normal matter, the ratio between electromagnetic and gravitational fields is given by the difference in the respective permeabilities. However, magnetic fields generated as a consequence ... |
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| Possible Gravitational Anomalies in Quantum Materials. Phase 1: Experiment Definition and Design |
FEB 2007 |
57 pages |
| Authors:
M. Tajmar; K. Hense; AUSTRIAN RESEARCH CENTERS SEIBERSDORF RESEARCH (ARCS) SEIBERSDORF (AUSTRIA)
|
| One of the authors (MT) recently published a paper, suggesting for the first time that a reported disagreement between experimental measurements and theoretical predictions for the magnetic field in rotating superconductors might arise from an anomalous high-order gravitomagnetic contribution (also known as frame dragging or Lense-Thirring effect). In normal matter, the ratio between electromagnetic and gravitational fields is given by the difference in the respective permeabilities. However, magnetic fields generated ... |
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| Advanced Interconnect and Device-Field Modeling |
15 JAN 2007 |
13 pages |
| Authors:
Mohamed Essaaidi; ABDELMALEK ESSAADI UNIV TETUAN (MOROCCO) FACULTY OF SCIENCES
|
| This final report describes the progress that has been made with the different tasks of this project. The highlights are that most of the tasks planned for this project have been carried out and completed successfully with some delay owing to some technical problems that could not be avoided. Those tasks concerned the development of OOP codes using C++ based on the Method of Moments for microwave interconnections analysis considering ... |
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| Metamaterials for Antenna Technologies |
15 SEP 2006 |
56 pages |
| Authors:
Sridar Sriniva; NORTHEASTERN UNIV BOSTON MA
|
| This project was centered around research and development of next generation metamaterials that are needed in radar technologies. Results were obtained in metamaterials that display negative refraction properties. New metamaterial designs were developed and new phenomena arising from the negative refraction properties were demonstrated . The work in this area has led to some major results, reported in 10 published papers. |
|
| A Study of Impact Response of Electrified Organic Matrix Composites (Preprint) |
SEP 2006 |
21 pages |
| Authors:
Robert L. Sierakowski; Igor Y. Telichev; Olesya I. Zhupanska; AIR FORCE RESEARCH LAB EGLIN AFB FL MUNITIONS DIRECTORATE
|
| The existing experimental evidence suggests that organic matrix composites sustain less impact damage when an electric field is applied. The intricate interaction of an electrical field and mechanical load is governed by coupling of the mechanical and electromagnetic fields via the Lorentz force as well as by the processes undergoing at the microscopic level: Joule heat, fiber-matrix interface changes, etc. The current work includes both experimental and theoretical investigations of ... |
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| Description of Spherical Aberration and Coma of a Microlens Using Vector Diffraction Theory (Postprint) |
SEP 2006 |
14 pages |
| Authors:
Glen D. Gillen; Shekhar Guha; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
|
| Light distributions of a plane wave refracted by a microlens are calculated using Kirchhoff vector diffraction theory. Numerical results for one and two-dimensional beam profiles and the onset and effects of spherical aberration and coma are investigated for different lens parameters. |
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| Assessment of an Active Electromagnetic Sensor for Hunting Buried Naval Mines, Part II |
Sep-2006 |
9 pages |
| Authors:
P J Carroll; W M Wynn; J W Purpura; NAVAL SURFACE WARFARE CENTER PANAMA CITY FL
|
| The US Navy is investigating the use of broadband electromagnetic (EM) sensors as a candidate technology for its Buried Minehunting (BMH) sensor suite. New Navy tactics are being pursued, where short-range sensors are incorporated into reacquisition minehunting systems for short-range classification. The current approach includes study of use of active EM sensors that employ multi-frequency sources for target illumination which can provide valuable multi-spectral discrimination for the classification of buried ... |
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| Ferrite Materials for Advanced Multifunction Microwave Systems Applications |
05 JUL 2006 |
17 pages |
| Authors:
Carl E. Patton; Jerome J. Green; COLORADO STATE UNIV FORT COLLINS DEPT OF PHYSICS
|
| ONR Grant N00014-03-1-0070 has supported a research program with a focus on new materials for applications in the 6-18 GHz range relevant to the AMRFS (Advanced Multifunctional RF systems) Navy program. The program has emphasized three dates of materials, yttrium iron garnet (YIG) and compositional variants, lithium ferrites and compositional variants, and hexagonal ferrites. Polycrystalline and single crystal materials in bulk and thin film form were investigated. These materials were ... |
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| Enhanced Spontaneous Emission of Bloch Oscillation Radiation from a Single Energy Band |
30 JUN 2006 |
24 pages |
| Authors:
G. J. Iafrate; NORTH CAROLINA STATE UNIV AT RALEIGH DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| In this study, we explored the possibility of enhanced spontaneous emission of radiation beyond the free space value by analyzing a superlattice structure placed in a microcavity whose resonant modes were tuned to the Bloch frequency. In particular, we considered the spontaneous emission of Bloch radiation into the rectangular waveguide dominant mode. In the analysis, the quantum radiation field was described by the waveguide quantized electromagnetic field in the Coulomb ... |
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| Wireless Sensor Network: Channel Propagation Measurements and Comparison With Simulation |
JUN 2006 |
83 pages |
| Authors:
Mohamad H. Alzaghal; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Wireless Sensor Networks (WSNs) is an important field of study as more and more applications are enhancing daily life. The technology trend is to achieve small-sized, cheap, and power efficient sensor nodes, which will make the system reliable and efficient. The Crossbow Technologies MICAz mote is an example used in this thesis. Measurements for its propagation characteristics in a realistic environment will help the deployment and installation of these motes ... |
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| Pulsed THZ Interrogation of Sofi With Knit Lines in 2D |
2006 |
16 pages |
| Authors:
H. T. Banks; N. L. Gibson; W. P. Winfree; NORTH CAROLINA STATE UNIV AT RALEIGH CENTER FOR RESEARCH IN SCIENTIFIC COMPUTATION
|
| This paper examines the scattering effect of knit lines and voids in SOFI through simulations of THz interrogation at normal and non-normal angles of incidence and using focused and non-focused single-cycle plane waves. We model the electromagnetic field using the TE mode of the 2D Maxwell's equations reduced to a wave equation, which are then solved with a finite-element time-domain method. The knit lines are modeled by changing the dielectric ... |
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| Simulation of Gas-Filled Diodes With the VORPAL Code |
28 SEP 2005 |
21 pages |
| Authors:
Peter Stoltz; Chet Nieter; Jean-Luc Cambier; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
|
| Researchers are interested in rapid switching high-current diodes for applications including accelerators, microwave sources, and flat panel displays. Gas-filled diodes, such as the pseudospark, are one class of candidates for such high-current applications. To yield a better understanding of their operation, numerical simulations of these devices must include a number of physical processes: gas ionization, secondary electron emission and ion-induced electron emission, and radiation. We are enhancing the VORPAL code ... |
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| Algorithm Development for the Two-Fluid Plasma Model |
28 SEP 2005 |
20 pages |
| Authors:
Uri Shumlak; WASHINGTON UNIV SEATTLE DEPT OF AERONAUTICS AND ASTRONAUTICS
|
| A new algorithm is developed based on the complete two-fluid plasma model. The model captures physics that is not contained in the more common magnetohydrodynamic model. Recent progress on the algorithm development for the two-fluid plasma model includes analysis of the simulation results, extension to two dimensions, and preliminary investigation of a higher order method. The algorithm is first developed in one dimension and applied to the electromagnetic plasma shock. ... |
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| Modeling of Power Combining in Microstrips with Active Devices for THz Applications |
29 AUG 2005 |
27 pages |
| Authors:
Vladimir Yurchenko; NATIONAL UNIV OF IRELAND MAYNOOTH (IRELAND)
|
| This report results from a contract tasking National University of Ireland as follows: The Grantee will investigate methods to increase power output of THz arrays. Simulations will be used to build models of various array structures. |
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| Electromagnetic Inverse Problems Involving Distributions of Dielectric Mechanisms and Parameters |
17 AUG 2005 |
52 pages |
| Authors:
H. T. Banks; N. L. Gibson; NORTH CAROLINA STATE UNIV AT RALEIGH CENTER FOR RESEARCH IN SCIENTIFIC COMPUTATION
|
| We consider electromagnetic interrogation problems for complex materials involving distributions of polarization mechanisms and also distributions for the parameters in these mechanisms. a theoretical and computational framework for such problems is given. Computational results for specific problems with multiple Debye mechanisms are given in the case of discrete, uniform, log-normal, and log-Bi-Gaussian distributions. |
|
| Plasmonic Devices and Materials |
30 JUN 2005 |
10 pages |
| Authors:
Harry A. Atwater; CALIFORNIA INST OF TECH PASADENA
|
| This final technical report reviews our scientific and technical development in the area of new plasmonic devices and material undertaken during our AFOSR support from July 2002-June 2005. This report contains a summary overview of scientific and technical progress and results over the entire program. It also provides detail about recent technical conducted during Period of the present grant. Our work since the inception of the program has focused on ... |
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| Study of Magnetogasdynamic Flow Acceleration in a Scramjet Nozzle |
JUN 2005 |
81 pages |
| Authors:
Erik K. Ross; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| The research project studied the benefits of Magnetogasdynamic (MGD) acceleration on a scramjet nozzle. MGD is a technology that relies on electromagnetic fields to extract and/or add energy to flow fields. The scramjet engine in the "AJAX" concept proposed by D.I. Brichkii et al. (2001) of St. Petersburg, Russia would utilize an MGD power generator in the diffuser user which could potentially provide electrical power for the aircraft support systems ... |
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| Hybrid Gas/Plasma Simulations Using DSMC with the VORPAL Code |
MAY 2005 |
14 pages |
| Authors:
Wen-Lan Wang; Chet Nieter; Peter Stoltz; Jean-Luc Cambier; TECH-X CORP BOULDER CO
|
| We are adding a Direct Simulation Monte Carlo model to the plasma simulations code VORPAL to model dilute (large Knudsen number) gases. This will allow VORPAL to run hybrid simulations of gas/plasma mixtures using the current plasma simulation capabilities of VORPAL along with the newly added DSMC capabilities. VORPAL is a multidimensional, parallel Particle-in-Cell plasma simulation code that supports a variety of models for both the plasma and electromagnetic fields. ... |
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| ExB Measurements of a 200 W Xenon Hall Thruster |
MAY 2005 |
10 pages |
| Authors:
J. M. Ekholm; W. A. Hargus Jr.; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
|
| Angularly resolved ion species fractions of Xe+1, Xe+2, and Xe+3 in the Busek BHT-200-X3 xenon Hall thruster plume were measured using an ExB probe for several operating conditions. The thruster was operated at nominal anode potential of 250 V and swept from 200 V to 325 V in 25 V increments. The ExB probe was placed 60 cm downstream of the exit plane and rotated up to 90 degrees from ... |
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| Optical Boron Nitride Insulator Erosion Characterization of a 200 W Xenon Hall Thruster |
MAY 2005 |
11 pages |
| Authors:
William A. Hargus Jr; Joshua Strafaccia; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
|
| Vacuum ultraviolet emission (137.9 nm) of boron neutrals sputtered from a 200 W xenon Hall thruster boron nitride insulator is evaluated as a diagnostic for real-time evaluation of thruster insulator erosion. Three Hall thruster plasma control variables are examined: ion energy (discharge potential), ion flux (propellant flow), and plasma conductivity (magnetic field strength). The boron emission, and hence the insulator erosion rate, varies linearly with ion energy and ion flux. ... |
|
| Narrowband vs. Wideband Radar Experiment: Precursor Data Acquisition |
15 APR 2005 |
4 pages |
| Authors:
Timothy E. Olson; Colby Dill III; VALHALLA TECHNOLOGIES LLC DELAND FL
|
| Design of a narrowband vs. wideband experiment was conducted as proposed. The system was operationally tested and a great deal of data was gathered and provided to the Air Force. This data suggests the future viability of such a wideband system. We also proposed the future testing protocol, by which the project can be brought to a higher level and hopefully transitioned into production. |
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| Breaking Waves and Microwave Polarimetric Emissivities: Final Report |
11 APR 2005 |
6 pages |
| Authors:
William E. Asher; WASHINGTON UNIV SEATTLE APPLIED PHYSICS LAB
|
| Several field experiments designed to provide a detailed look at the physical processes affecting the microwave radiometric signal from breaking waves and foam patches were conducted. Significant results included: 1) Showed that the microwave emissivity of a foam covered water surface does not behave as a blackbody in the microwave region. 2) Provided further evidence that fraction area whitecap coverage can be estimated from microwave brightness temperature. 3) Provided new ... |
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| Modeling an HF NVIS Towel-Bar Antenna on a Coast Guard Patrol Boat. A Comparison of WIPL-D and the Numerical Electromagnetics Code (NEC) |
01 JAN 2005 |
|
| Authors:
Darla Mora; Christopher Weiser; Michael McKaughan; COAST GUARD ACADEMY NEW LONDON CT
|
 | A Coast Guard patrol boat high-frequency (HF) near-vertical incident skywave (NVIS) antenna is selected as a test case to compare the electromagnetic modeling programs Numerical Electromagnetics Code, NEC and WIPL-D code. Differences between the models and program outputs will be presents. The radiation pattern predictions will be compared. Agreement between the results is found to be good. Minor adjustments of the two coordinate systems of the programs are necessary. A ... |
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| Numerical Studies of Low Grazing Angle Microwave Scattering from Breaking Water Waves |
JAN 2005 |
20 pages |
| Authors:
James C. West; OKLAHOMA STATE UNIV STILLWATER SCHOOL OF ELECTRICAL AND COMPUTER ENGINEERING
|
| The microwave backscattering from breaking water waves at small illumination Grazing angles (LGA) has been investigated using computational electromagnetics (CEM) techniques. Good agreement is achieved between the numerically calculated and experimentally measured backscattering from a wave tank plunging breaker. The large measured HH/VV polarization ratio is due to the shape of the wave crest and the multi-path scattering from the wave crest and front face. The HH/W ratio is maintained ... |
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| Low-Frequency EM Field Penetration Through Magnetic and Conducting Cylindrical Shields |
2005 |
5 pages |
| Authors:
Michael A. Morgan; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| Computation of low-frequency field penetration through magnetic and/or conducting materials is important for quantifying electromagnetic compatibility issues in devices and facilities, as well as prediction of field signatures external to ships and submarines due to internal electrical machinery. A computational procedure is described for accurately predicting the penetration of low-frequency fields through a cylindrical structure, possibly arranged in layers. The internal source being shielded is a large multi-turn coil having ... |
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| Computational Electromagnetics |
DEC 2004 |
15 pages |
| Authors:
Fernando Reitich; MINNESOTA UNIV MINNEAPOLIS SCHOOL OF MATHEMATICS
|
| The objective of the effort sponsored by the present contract consists of the development of a suite of numerical algorithms, founded on a rigorous mathematical basis for the accurate and efficient prediction of electromagnetic scattering returns. The techniques are based on Integral equations, perturbation theory and high frequency approximations; general numerical methods will be sought through suitable combinations of these. |
|
| An Experimental Investigation of the Nonlinear Response of Thin-Walled Ferromagnetic Shields to Short-Duration Current Pulses |
DEC 2004 |
9 pages |
| Authors:
W. J. Croisant; M. K. McInerney; C. A. Feickert; P. H. Nielsen; CONSTRUCTION ENGINEERING RESEARCH LAB (ARMY) CHAMPAIGN IL
|
| Intense electromagnetic (EM) fields can disrupt, disable, damage, or destroy sensitive electronic equipment that is needed to perform critical functions such as those related to command, control, communications, computer, intelligence, surveillance, and reconnaissance (C4ISR). EM shielding is used to protect equipment against such detrimental effects to promote the survivability of mission critical systems. Ferromagnetic materials can have a high magnetic permeability, which may be a significant advantage in shielding applications; ... |
|
| An Approximate Method for Modelling Laser Light Scattering from Biological Cells |
OCT 2004 |
|
| Authors:
Y. Shao; E. Yee; DEFENCE RESEARCH AND DEVELOPMENT SUFFIELD (ALBERTA)
|
| A new technique for approximating the scattering of laser light by biological cells is reported. This technique is based on a three-dimensional scalar wave equation approximation of the full Maxwell's field equations for the electromagnetic field. This scalar wave equation for describing the light scattering patterns of cells containing arbitrary morphological structure (e.g., various organelles) is solved numerically using a spectral method. The accuracy of the spectral numerical method is ... |
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| An FPGA Implementation of the Two-Dimensional Finite-Difference Time- Domain (FDTD) Algorithm |
20 AUG 2004 |
26 pages |
| Authors:
Wang Chen; Miriam Leeser; Carey Rappaport; Panos Kosmas; NORTHEASTERN UNIV BOSTON MA DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| Three-Dimensional Finite-Difference Time-Domain (3D FDTD) is a powerful method for modelling the electromagnetic field. The 3D FDTD buried object detection forward model is emerging as a useful application in mine detection and other subsurface sensing areas. However, the computation of this model is complex and time consuming. Implementing this algorithm in hardware will greatly increase its computational speed and widen its use in many other areas. We present an FPGA ... |
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| Transient Sheets of Field-Aligned Current Observed by DMSP During the Main Phase of a Magnetic Superstorm |
16 JUN 2004 |
18 pages |
| Authors:
Cheryl Y. Huang; William J. Burke; AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE VEHICLES DIRECTORATE
|
| Reported are the first observations of intense (^1 A/m) but transient sheets of field-aligned currents (FACS) that couple of the central plasma sheet with the auroral ionosphere near the maximum epochs of magnetic superstorms. Maximum magnetic perturbations associated with the FACs normally develop at middle (55 deg - 60 deg) magnetic latitudes. Our attention was drawn to these phenomena while comparing ground magnetometer responses to measurements by particle and field ... |
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| Passage of Energetic Particles Through Matter |
07 MAY 2004 |
163 pages |
| Authors:
N. J. Carron; MISSION RESEARCH CORP SANTA BARBARA CA
|
| This report collects cross sections for photons passing through matter. A thorough discussion of the background physics is provided, together with graphs for many processes. This material, together with additional similar material for electrons, heavy ions (protons and heavier) and neutrons, is to be published by IOP Publishing, in late 2004 or early 2005. |
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| Modal Expansion Functions Combined with EFIE Applied to Air Intake/Engine RCS Computations |
23 APR 2004 |
9 pages |
| Authors:
Andre Barka; Beatrice Fromentin; Sophie Langlet; OFFICE NATIONAL D'ETUDES ET DE RECHERCHES AEROSPATIALES TOULOUSE (FRANCE) DEMR
|
| In this paper we will describe a sub-domain method based on integral equations devoted to the RCS analysis of Air Intake and rotating fans. The accuracy and efficiency of theses techniques will be demonstrated for the CHANNEL 1/4 scaled mock-up. During the computation a set of sub-domain will be calculated and connected in a final step. The RCS results will be compared with measurements on the CHANNEL mock-up for 2 ... |
|
| Alpha Test Analysis of WIPL-DP |
23 APR 2004 |
8 pages |
| Authors:
Saad Tabet; Laurie Joiner; Milissa Benincasa; NAVAL AIR SYSTEMS COMMAND PATUXENT RIVER MD
|
| WIPL-D (WIre PLate Dielectric) has become an increasingly popular Method of Moments (MoM) code used in computational electromagnetics (CEM) modeling. WIPL-D was chosen for parallelization under the Common High Performance Computing Software Support Initiative (CHSSI) program of the High Performance Computing Modernization Office (HPCMO). Hence, the new code was given the name WIPL-DP, where "P" stands for Parallelized. Any computer code chosen for parallelization under the CHSSI program must undergo ... |
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| Electromagnetic Modeling of an Adaptable Multimode Microwave Applicator for Polymer Processing |
23 APR 2004 |
7 pages |
| Authors:
Rensheng Sun; Leo C. Kempel; Shuangjie Zhou; Liming Zong; Martin C. Hawley; MICHIGAN STATE UNIV EAST LANSING
|
| Microwaves have been investigated as an attractive alternative (and efficient) energy source to inefficient pressurized ovens for polymer processing. However, industrial use of microwave processing has been impeded by the lack of proper applicator design, modeling, and control/monitoring methods. In this paper, we will briefly talk about conventional multimode applicators, waveguide applicators, and recently developed single-mode applicators. Then we will present the electromagnetic modeling of a novel adaptable multi-feed multimode ... |
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| Performance Enhancement of High Speed Inlets using MHD |
30 MAR 2004 |
84 pages |
| Authors:
Shashi Aithal; Ramakanth Munipalli; Vijaya Shankar; HYPERCOMP INC WESTLAKE VILLAGE CA
|
| HyPerComp is developing advanced computational tools to model high speed flows with MHD effects. Unstructured, multi-dimensional hypersonic MHD codes have been developed at HyPerComp to study supersonic viscous flows in a self-consistent, fully coupled manner. Effects of thermal, chemical and internal mode dis-equilibrium with and without the presence of electro-magnetic fields have been included in these codes. An existing parallel code environment using generalized mesh structure (prisms, tetrahedra, etc.) developed ... |
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| Acoustic Properties of Toroidal Bubbles and Construction of a Large Apparatus |
MAR 2004 |
77 pages |
| Authors:
Ashley M. Harris; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| When a burst of air is produced in water, the result can be a toroidal bubble. This thesis is concerned with experimental investigations of three acoustical properties of toroidal bubbles: (i) propagation through high- intensity noise, (ii) emission, and (iii) scattering. In (i), an attempt to observe a recent prediction of the acoustic drag on a bubble is described, which is analogous to the Einstein-Hopf effect for an oscillating electric ... |
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| The Tilted-Ellipse Representation of Standing-Wave Patterns |
24 FEB 2004 |
54 pages |
| Authors:
Ross A. Speciale; RESEARCH AND DEVELOPMENT INC REDONDO BEACH CA
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| A recently introduced, new computer-simulation method provides a fast and inexpensive way for obtaining the multi-dimensional scattering matrices of even very large-scale, multiport microwave systems. The new method simulates measurements of multidimensional, complex scattering matrices, that could only be performed using a very large and expensive multiport Vector Network Analyzer (VANA). Calibrated measurements of complex scattering matrices of any arbitrary size may be simulated by using any available frequency-domain 2D ... |
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| Possible Gravitational Anomalies in Quantum Materials |
12 FEB 2004 |
104 pages |
| Authors:
M. Tajmar; K. Hense; AUSTRIAN RESEARCH CENTERS SEIBERSDORF RESEARCH (ARCS) SEIBERSDORF (AUSTRIA)
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| One of the authors (MT) recently published a paper, suggesting for the first time that a reported disagreement between experimental measurements and theoretical predictions for the magnetic field in rotating superconductors might arise from an anomalous high-order gravitomagnetic contribution (also known as frame dragging or Lense-Thirring effect). In normal matter, the ratio between electromagnetic and gravitational fields is given by the difference in the respective permeabilities. However, magnetic fields generated ... |
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