| Development of a Charged-Particle Accumulator Using an RF Confinement Method |
29-Sep-2009 |
7 pages |
| Authors:
Ryogo S Hayano; TOKYO UNIV (JAPAN)
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 | This report describes the excellent progress made in constructing a Paul Trap, despite all the difficulties encountered by researchers at CERN. |
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| Investigation of Low Discharge Voltage Hall Thruster Operating Modes and Ionization Processes |
14-Aug-2009 |
45 pages |
| Authors:
Daniel L Brown; Alec D Gallimore; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
|
| A study of low discharge voltage Hall thruster operation revealed the existence of two operating regimes. Small variations in cathode flow fraction and magnetic field resulted in sharp changes in discharge current with constant thrust, corresponding to a visible change in the jet-mode plume structure. The phenomenon is characterized with a systematic map of thruster operation for discharge voltages ranging from 100 - 120 V, anode flow rates from 10 ... |
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| Acceleration of an Initially Moving Projectile: Velocity-Injected Railguns and Their Effect on Pulsed Power |
Jul-2009 |
30 pages |
| Authors:
Del; Miguel Guercio; Alexander Zielinski; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
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| Calculations are performed for an initially moving projectile and a railgun. The initial velocity is provided by a 26-mm-diameter conventional propellant gun. A plasma armature is assumed for the railgun. The capacitor-based, pulsed power supply (PPS), located at barricade C, Aberdeen Proving Ground, MD, is assumed to provide the electrical energy for boosting the velocity to 2.5 km/s. Various scenarios are examined with respect to electrical pulse shape, the effect ... |
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| An Elegant Low-cost Materials Solution for Achieving Low Insertion Loss, Affordable Tunable Filters for Next Generation Mobile Communications Platforms |
Apr-2009 |
18 pages |
| Authors:
M W Cole; E Ngo; R J Tan; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
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| The effect ultraviolet (UV)-assisted annealing on the structural, dielectric, and insulating properties of barium strontium titanate (BST) thin films was investigated. The material properties of BST films, prepared by RF sputter deposition, annealed via conventional thermal annealing and UV-assisted thermal annealing process protocols were compared and evaluated. The x-ray diffraction results showed contracted lattice constants and enhanced crystallinity for the RF sputtered BST films annealed via the UV-assist treatment. Isothermal-temporal ... |
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| Electrostatic Discharge Properties of Irradiated Nanocomposites |
Mar-2009 |
121 pages |
| Authors:
Joshua D McGary; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT/DEPT OF ENGINEERING PHYSICS
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| Modernization in space systems requires employment of new light-weight, high performance composite materials that reduce bulk weight and increase structural integrity. This thesis explored the behavior of one such material prior to and following a 35-year simulated space radiation life-cycle. Select electrical properties of nickel nanostrand(TradeMark)-carbon composites in seven configurations were characterized prior to electron irradiation via surface and bulk resistivity measurements and contact electrostatic discharge (ESD) measurements. Following irradiation ... |
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| Carbon Nanotube Array for Infrared Detection |
05-Dec-2008 |
17 pages |
| Authors:
Jimmy Xu; BROWN UNIV PROVIDENCE RI DIV OF ENGINEERING
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| We explore the basic science issues and device potential of our carbon nanotube-silicon (CNT-Si) heterojunctions for infrared photodetection. We focus on the underlying mechanism of infrared photocurrent response, which is elucidated by a detailed study of the dependence of the photocurrent on modulation frequency and intensity of the incident infrared radiation. The photocurrent generation is ascribed to the formation of the CNT-Si heterojunction, rather than the thermal gradient in the ... |
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| Control and Optimization of Coherence of a Nano-Sized Spin-Torque Microwave Oscillator for Military Nano-Electronics |
30-Nov-2008 |
27 pages |
| Authors:
G Gerhart; E Bankowski; V S Tiberkevich; A N Slavin; ARMY RESEARCH DEVELOPMENT AND ENGINEERING COMMAND WARREN MI
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| Passage of an electric current through a multilayered magnetic nano structure can lead to the excitation of a persistent magnetization precession in the thinner (free) magnetic layer of the structure. The frequency of the excited auto oscillations is close to the ferromagnetic resonance frequency and typically lies in the microwave frequency range. This effect can be used for the development of a novel class of fully metallic microwave nano sized ... |
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| Visualization of Coupling Current Paths in Striated YBCO-Coated Conductors at Frequencies up to 400 HZ |
01-Oct-2008 |
7 pages |
| Authors:
E Demencik; P Usak; S Takacs; I Vavra; M Polak; G A Levin; P N Barnes; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH PROPULSION DIRECTORATE
|
| The magnetic flux density component perpendicular to the broad tape face was mapped by miniature Hall probes in the vicinity of a striated YBCO-coated tape at frequencies of external magnetic field from 21 to 400 Hz, applied perpendicularly to the tape surface. For reasons of modeling the coupling current behaviour in tapes with a conductive substrate, we amplified the coupling current-amplitude by soldering 25 microns thick copper foil on the ... |
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| The Concept of Electrically Assisted Friction Stir Welding (EAFSW) and Application to the Processing of Various Metals |
01-Sep-2008 |
33 pages |
| Authors:
William A Ferrando; NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD SURVIVABILITY STRUCTURES AND MATERIALS DIRECTORATE
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| This report introduces a novel variant of conventional friction stir welding (FSW). Since 1991, friction stir welding provides an alternative to arc welding as a metal joining method in numerous applications. In FSW, the heat required to soften the target metal is generated totally by the rotating friction of the tool which necessitates rather high downward (Z) operating force and often leads to relatively short tool life. In the proposed ... |
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| Low Temperature Photoluminescence and Leakage Current Characteristics of InAs-GaSb Superlattice Photodiodes |
01-Sep-2008 |
20 pages |
| Authors:
P A Folkes; J Little; S Svensson; K Olver; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| We report the results of a study of the temperature-dependent photoluminescence (PL) and leakage current characteristics of a set of type II idium arsenide (InAs)-gallium antimonide (GaSb) superlattice (SL) photodiode structures. We find that the PL efficiency of high-quality structures is determined by Shockley-Read and trap-assisted tunneling nonradiative recombination processes. Our results suggest a possible correlation between trap-assisted tunneling in some SL structures and an anomalous decrease in the PL ... |
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| Electron Transport in Boron Fullerenes |
Aug-2008 |
4 pages |
| Authors:
Ravindra Pandey; Haiying He; Shashi P Karna; Ihsan Boustani; MICHIGAN TECHNOLOGICAL UNIV HOUGHTON DEPT OF PHYSICS
|
| The electron transport properties of B80 fullerene are studied using first-principles density functional theory in conjunction with the Landauer-Buettiker quantum transport formalism. The electron transmission in B80 fullerene is calculated to be much higher than that in C60 fullerene in the Fermi-level region. The enhanced transmission in the B80 fullerene is attributed to its spatially extended charge distribution in delocalized bonds. |
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| Effect of Anode Current Fluctuations on Ion Energy Distributions within a 600 W Hall Effect Thruster (Preprint) |
23-Jun-2008 |
11 pages |
| Authors:
Michael R Nakles; Hargus; William A Jr; Rachel Tedrake; Bruce Pote; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
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| This work presents axial ion energy distribution measurements within the acceleration channel of the 600 W Busek Co. Inc. BHT-HD-600 laboratory Hall thruster derived from laser-induced fluorescence measurements of the 5d[4](sub 7/2) - 6p[3](sub 5/2) xenon ion excited state transition. Acceleration channel centerline ion energy distributions are measured for three closely related operating conditions which only differ in the magnitude of the radial magnetic field strength. These three operating conditions ... |
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| Studies of Spin Amplifier for Logic Applications |
NOV 2007 |
7 pages |
| Authors:
Pallab Bhattacharya; MICHIGAN UNIV ANN ARBOR DEPT OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCE
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| A ferromagnet/semiconductor based electrically controlled spin-current amplifier using a dual-drain non-local lateral spin valve was demonstrated. The spin polarization injected by the source into the channel was amplified at the second drain contact. An amplified current spin polarization of 100% was measured. The device provided controlled spin-current gain, which was varied in the entire range from -1 to +1. The controlled variation of amplifier gain with bias was also demonstrated. ... |
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| High Rate Lithium-Ion Cell Testing |
01-Sep-2007 |
3 pages |
| Authors:
Stuart Santee; Seth Cohen; Joe DiCarlo; Frank Puglia; Joe Wallace; YARDNEY TECHNICAL PRODUCTS INC PAWCATUCK CT
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| Lithion, a Division of Yardney Technical Products, constructed lithium-ion cells to improve electrode coatings, separators, electrolytes, and other aspects of cell design. Lithium-ion batteries, with their exceptional energy density and cycle-life performance, are replacing other rechargeable battery systems in many applications. With the continued development of applications such as directed energy weapons, unmanned aerial vehicles, and aircraft batteries, lithium-ion technology must continue to develop its high pulse power and high ... |
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| A Planar Hall Thruster for Investigating Electron Mobility in ExB Devices (Preprint) |
24 AUG 2007 |
13 pages |
| Authors:
Joshua L. Rovey; Matthew P. Giacomi; Robert A. Stubbers; Brian E. Jurczyk; STARFIRE INDUSTRIES LLC CHAMPAIGN IL
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| Stable operation of a Hall thruster that emits and collects the Hall current across a planar discharge channel is described. The planar Hall thruster (PHT) is being investigated for use as a test bed to study electron mobility in ExB devices. The planar geometry attempts to de-couple the complex electron motion found in annular thrusters by using simplified geometry. During this initial test, the PHT was operated at discharge voltages ... |
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| High Efficiency and Long Life Photovoltaic Research for Space Applications |
05 JUL 2007 |
12 pages |
| Authors:
Wei-Fang Su; NATIONAL TAIWAN UNIV TAIPEI (TAIWAN) DEPT OF MATERIALS SCIENCE AND ENGINEERING
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| We have developed a tree-like nanostructured photovoltaic device based on the polymer poly"3-hexylthiophene""P3HT"/metal oxide hybrid materials by solution processes at low temperature. An array of large ZnO nanorods with a larger size of 50 nm in diameter and 150 nm in length are grown to act as tree trunks for efficient charge collection. Small TiO2 nanorods with a size of 5 nm in diameter and 20 nm in length are ... |
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| Shipboard Fluid System Diagnostics Using Non-Intrusive Load Monitoring |
Jun-2007 |
91 pages |
| Authors:
Gregory R Mitchell; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF MECHANICAL ENGINEERING
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| Systems on modern naval vessels are becoming exclusively dependent on electrical power. One example of this is the replacement of distilling and evaporator plants with reverse osmosis units. As the system is in continuous operation, it is critical to have remote real-time monitoring and diagnostic capabilities. The pressure to reduce shipboard manning only adds to the difficulties associated with monitoring such systems. One diagnostic platform that is particularly well suited ... |
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| Implantation-Free 4H-SiC Bipolar Junction Transistors with Double Base Epi-layers |
14-May-2007 |
15 pages |
| Authors:
Jianhui Zhang; Petre Alexandrov; Terry Burke; Jian H Zhao; Xueqing Li; UNITED SILICON CARBIDE INC NEW BRUNSWICK NJ
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| This paper reports the first 4H-SiC power bipolar junction transistor (BJT) which is completely free of ion implantation and hence is free of the implantation-induced crystal damages and high-temperature activation annealing-induced surface roughness. The BJT is designed to have double epitaxial p-type base layers with the top layer more heavily doped for direct Ohmic contact formation while at the same time supporting a robust single-step junction termination extension without the ... |
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| Report on the Wisconsin-Stanford-Kansas-Davis-Florida State MURI on Scientific Challenges of Coated Conductors |
30 MAR 2007 |
6 pages |
| Authors:
David C. Larbalestier; WISCONSIN UNIV-MADISON APPLIED SUPERCONDUCTIVITY CENTER
|
| Coordinated, multi-institutional research (University of Wisconsin, Stanford University, the University of Kansas, the University of California-Davis, and Florida State University) is addressing key underlying scientific and engineering issues of Generation II Coated Conductors, and is fabricating and acquiring through collaborations forefront CC samples, developing new tools for their understanding and characterizing them so as to resolve key performance issues. Areas of concentration include substrates, buffer layers, the superconducting overlayer, their ... |
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| Large Volume Non-Equilibrium Air Plasma at Atmospheric Pressure: A Novel Method with Low Power Requirements |
28 FEB 2007 |
36 pages |
| Authors:
Mounir Laroussi; OLD DOMINION UNIV NORFOLK VA DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| This document is the final technical report on the research activities carried out under AFOSR Grant F49620-03-1-0325. Here we present our research results, which took place in the last three years and a half. Particularly, during the later period of performance the focus of our activities was on carrying out diagnostics on plasma devices based on new approaches that use high voltage narrow pulses to ignite the plasma. These novel ... |
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| Propellantless Propulsion: The Role of Drift Transport in Asymmetrical Capacitor Thrust Production |
01 NOV 2006 |
22 pages |
| Authors:
Steve J. Trettel; NEW PRAGUE HIGH SCHOOL NM
|
| CONCLUSION: Thrust dependent primarily on the current applied; * Polarity was not a major factor in thrust magnitude or direction; * Results of experimentation pointed towards an ionic model for thrust. |
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| GHz Modulation of GaAs-Based Bipolar Cascade VCSELs (Preprint) |
NOV 2006 |
6 pages |
| Authors:
W. J. Siskaninetz; R. G. Bedford; Jr. Nelson T. R.; J. E. Ehret; J. D. Albrecht; J. A. Lott; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH SENSORS DIRECTORATE
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| The high-frequency modulation characteristics of GaAs-based bipolar cascade vertical cavity surface emitting lasers operating at 980 nm with GaAs tunnel junctions and p-doped Al0.98Ga0.02As oxide apertures have been measured. We achieve -3 dB laser output modulations of 6.5 GHz for 2-stage and 9.4 GHz for 3-stage devices in response to small-signal current injection at an operating temperature of -50 ?C. |
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| Electronically Induced Redox Barriers for Treatment of Groundwater |
OCT 2006 |
44 pages |
| Authors:
Tom Sale; David Gilbert; COLORADO STATE UNIV FORT COLLINS ENGINEERING RESEARCH CENTER
|
| This report summarizes results from a 3-year collaboration between the Environmental Security Technology Certification Program (ESTCP) and Colorado State University (CSU). The focus is an innovative electrolytic approach for managing redox-sensitive contaminants in groundwater, referred to as electrically induced redox barrier (e-barriers). The overarching objective of the work is to demonstrate/validate a new technology for managing contaminated groundwater at the Department of Defense (DoD) facilities that holds promise in terms ... |
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| Nonsurgical Brain Activity Recovery From a Cap Containing Multiple Electroencephalogram Recording Sites |
SEP 2006 |
217 pages |
| Authors:
David Cohoon; L3 COMMUNICATIONS SERVICES GROUP SAN ANTONIO TX
|
| The goal of this project is to invert electroencephalogram data to brain activity using a novel and accurate algorithm. This algorithm can be used for research and development of brain-machine interfaces, potentially to include prosthetic control, surveillance and lie detection. This report details the mathematical and physical theory behind the algorithm developed during this effort. The algorithm is novel in that it does not use the quasistatic approximation throughout the ... |
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| A Fast, Parallelized Computational Approach Based on Sparse LU Factorization, for Predictions of Spatial and Time-Dependent Currents and Voltages in Full-Body Bio-Models |
AUG 2006 |
11 pages |
| Authors:
Ashutosh Mishra; Ravindra P. Joshi; Karl H. Schoenbach; III Clark C. D.; ADVANCED INFORMATION ENGINEERING SERVICES BROOKS CITY-BASE TX
|
| Realistic and accurate numerical simulations of electro-stimulation of tissues and full-body biomodels have been developed and implemented. Typically, whole-body systems are very complex and consist of a multitude of tissues, organs, and subcomponents with diverse properties. From an electrical standpoint, these can be characterized in terms of separate conductivities and permitivities. Accuracy demands good spatial resolution; thus, the overall tissue/animal models need to be discretized into a fine-grained mesh. This ... |
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| Nanoscale Polymeric Photocells by Advanced Electrospinning |
20 JUL 2006 |
51 pages |
| Authors:
Anvar Zakhidov; John Ferraris; Kenneth Balkus; TEXAS UNIV AT DALLAS RICHARDSON
|
| We presented detailed study of postproduction neat treatment of organic solar cells based on RR-P3HT:PCBM composite in a wide temperature range. The efficiency of such device was significantly Improved by postproduction heat treatment. Optimized parameters yielded >3% efficiency for devices on glass substrates and of |
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| Atomtronics: Ultracold Atom Analogs of Electronic Devices |
23 JUN 2006 |
13 pages |
| Authors:
B. T. Seaman; M. Kraemer; D. Z. Anderson; M. J. Holland; COLORADO UNIV AT BOULDER DEPT OF PHYSICS
|
| Atomtronics focuses on atom analogs of electronic materials, devices and circuits. A strongly interacting ultracold Bose gas in a lattice potential is analogous to electrons in solid-state crystalline media. As a consequence of the band structure, cold atoms in a lattice can exhibit insulator or conductor properties. P-type and N-type material analogs can be created by introducing impurity sites into the lattice. Current through an atomtronic wire is generated by ... |
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| Biological Fuel Cell Functional as an Active or Reserve Power Source |
JUN 2006 |
26 pages |
| Authors:
Jr Walker Charles W.; Alyssa L. Walker; ARMY RESEARCH LAB ADELPHI MD
|
| A biological fuel cell was constructed in which the metabolism of glucose by yeast provides the electrons. A two-compartment plexiglas fuel cell was constructed with platinum electrodes separated by a proton-conducting membrane. One half of the cell contained yeast, Saccharomyces cerevisiae, glucose, and an electron mediator, methylene blue. The other half contained an electron acceptor, potassium ferricyanide. Electrons produced during the metabolism of glucose by the yeast were captured by ... |
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| Characterization and Analysis of a Multicolor Quantum Well Infrared Photodetector |
JUN 2006 |
67 pages |
| Authors:
Nathan A. Hanson; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This thesis presents analysis and characterization of performance of a newly designed, multicolor quantum well infrared photodetector (QWIP). Specifically, it focuses on a detector capable of detecting infrared emissions in the near infrared (NIR), mid-wavelength infrared (MWIR), and long-wavelength infrared (LWIR). Through photocurrent spectroscopy and performance analysis, this prototype detector can be classified and prepared for possible future use within the U.S. Armed Forces. Certain military applications require a highly ... |
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| Evaluation of a 4 mm x 4 mm SiC GTO at Temperatures up to 150 degs C and Varying Pulse Width |
May-2006 |
5 pages |
| Authors:
Heather O'Brien; William Shaheen; Stephen B Bayne; ARMY RESEARCH LAB ADELPHI MD
|
| The U. S. Army Research Laboratory (ARL) is evaluating silicon carbide Super GTOs (SGTOs) [1] to determine the extent of silicon carbide's capabilities as a possible replacement for silicon in future pulsed switching applications. Individual SiC die measuring 4 mm x 4 mm were pulsed at high temperatures and varying pulse widths. These SGTOs were switched in an RLC circuit at temperatures up to 150 deg C. At this peak ... |
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| Pulsed Current Static Electrical Contact Experiment |
MAY 2006 |
11 pages |
| Authors:
Harry N. Jones; Jesse M. Neri; Craig N. Boyer; Khershed P. Cooper; Robert A. Meger; NAVAL RESEARCH LAB WASHINGTON DC
|
| Railguns involve both static and sliding electrical contacts, which must transmit the large transient electrical currents necessary to impart high forces onto a projectile for acceleration to hypervelocity. Static electrical contacts between metals initially take place through small asperities, or "a-spots", distributed over the contact area. The voltage developed across the interface is directly related to the contact temperature and pressure, the number of a-spots, the thermophysical and mechanical properties ... |
|
| Inductance of Parallel Plates in Electromagnetic Armor |
MAY 2006 |
36 pages |
| Authors:
Charles R. Hummer; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| In electromagnetic armor, a shaped charge jet is disrupted when a large current is passed through it while the jet is in contact with two parallel flat plates. For the current to increase as quickly as possible to an effective level, the inductance of the circuit must be controlled or at least known. This inductance, however, depends on the position of the current connections to the plates and the position ... |
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| Evaluation of 10 kV, 80 kA Si SGTO Switching Components for Army Pulsed Power Applications |
May-2006 |
5 pages |
| Authors:
Tim Crowley; Heather O'Brien; William Shaheen; Stephen B Bayne; ARMY RESEARCH LAB ADELPHI MD
|
| The U.S. Army Research Lab (ARL) is investigating the switching capabilities of advanced silicon devices for high current pulsed power applications. These solid state switches are intended to replace more traditional vacuum switches. The benefits of these switches are higher dI/dt, peak power levels and current densities, increased reliability and lifetime, and smaller switch volume. The peak current achieved by the device was 83.3 kA, with a 10% to 90% ... |
|
| Indium Gallium Nitride/Gallium Nitride (InGaN/GaN) Nanorods Superlattice (SL) |
29 MAR 2006 |
16 pages |
| Authors:
Tea W. Kang; DONGGUK UNIV SEOUL (KOREA)
|
| The growth condition, electrical, and optical properties of GaN nanorods grown on Si(111) substrates are investigated. The GaN nanorods were grown with a different growth time by using rf-plasma assisted molecular-beam epitaxy. It is clearly demonstrated that the critical diameter for defects-free GaN nanorods is determined to be below ~140 nm under the N-rich condition. Magnesium-doped GaN nanorods were also grown with the same growth condition. Two emission lines corresponding ... |
|
| Z-Pinch Plasma Neutron Sources |
24 MAR 2006 |
54 pages |
| Authors:
A. L. Velikovich; R. W. Clark; J. Davis; Y. K. Chono; C. Deeney; C. A. Coverdale; C. Ruiz; G. Cooper; J. Franklin; L. I. Rudakov; SANDIA NATIONAL LABS ALBUQUERQUE NM
|
| A deuterium gas-puff load imploded by a multi-MA current driver, from a large initial diameter could be a powerful source of fusion neutrons, a plasma neutron source. Unlike the beam-target neutrons produced in Z-pinch plasmas in the 1950s and deuterium-fiber experiments in the 1980s, the neutrons generated in deuterium gas-puffs, with current levels achieved in recent experiments on the SNL Z facility, could contain a substantial fraction of thermonuclear origin. ... |
|
| Characterization of the Field Emission Properties of Carbon Nanotubes Formed on Silicon Carbide Substrates by Surface Decomposition |
MAR 2006 |
180 pages |
| Authors:
Michael C. Pochet; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| Dense arrays of vertically aligned carbon nanotubes (CNTs) form on the surface of silicon carbide wafers during high temperature anneals under moderate vacuum conditions. The novelty of this growth method is that the CNTs form without the aid of a metal catalyst, allowing for potentially impurity-free CNTs to form. In this study, CNT films were grown by the surface decomposition of silicon carbide substrates. The associated field emission characteristics were ... |
|
| Use of Synthetic Nerve Grafts to Restore Cavernous Nerve Function Following Prostate Cancer Surgery: In Vitro and In Vivo Studies |
MAR 2006 |
9 pages |
| Authors:
Badrinath R. Konety; CALIFORNIA UNIV SAN FRANCISCO
|
| The hypothesis of this proposal is that interposition of micropatterned biodegradable polymer based nerve grafts to replace resected or damaged cavernous nerves can facilitate return of erectile function by engendering directional nerve growth in an animal model. Micropatterned grafts have been produced using a biodogradable polymer (PDFA) The groove oharaotceristics obtained by micropatterning will be optimized to allow maximal directional neurite growth have been optimized The effect of laminin +/- ... |
|
| Hypersonic Inlet With Plasma Induced Compression (Postprint) |
JAN 2006 |
15 pages |
| Authors:
J. S. Shang; J. Menart; Roger L. Kimmel; J. Hayes; WRIGHT STATE UNIV DAYTON OH DEPT OF MECHANICAL AND MATERIALS ENGINEERING
|
| A path-finding experimental investigation has been successfully accomplished to show the combined effect of an electromagnetic perturbation and viscous-inviscid interaction is a viable mechanism for improving hypersonic inlet performance. The plasma-induced compression is produced by a direct current discharge from electrodes embedded in the sidewalls of a rectangular constant cross-sectional area inlet. This repeatable compression acts as the sidewall compression of a variable area inlet but without the parasitic effect ... |
|
| High-Voltage Power Switching for a Conducting Tether |
2006 |
11 pages |
| Authors:
Sriram Harkare; Roger Dougal; Joseph A. Carroll; Shengyi Liu; SOUTH CAROLINA UNIV COLUMBIA
|
| The ElectroDynamic Delivery Express (EDDE) is an autonomous space vehicle that can maneuver throughout low earth orbit without using fuel. EDDE uses solar power to drive multi-ampere currents through a kilometers-long aluminum conductor, creating a force normal to both the conductor and the local magnetic field that drives the space vehicle. The tether spins at about 8 times/orbit. This stabilizes its dynamics and also allows a wider range of electrodynamic ... |
|
| Orbital Maneuvering With Spinning Electrodynamic Tethers |
2006 |
8 pages |
| Authors:
Jerome Pearson; Eugene Levin; Joseph A. Carroll; John C. Oldson; STAR TECHNOLOGY AND RESEARCH INC MOUNT PLEASANT SC
|
| Electrodynamic tethers produce low thrust through interaction of the electric current in the tether with the Earth's magnetic field. The thrust is comparable with that of ion rockets and Hall thrusters, and they have the added advantage that they are propellantless, allowing them to produce an order of magnitude greater velocity changes than ion rockets. However, the long conductors of such electrodynamic thrusters typically exhibit unstable behaviors with higher currents. ... |
|
| Ablation Study in a Capillary Sustained Discharge |
2006 |
11 pages |
| Authors:
Michael Keidar; Iain D. Boyd; Anthony Williams; Richard Beyer; MICHIGAN UNIV ANN ARBOR DEPT OF AEROSPACE ENGINEERING
|
| Electrothermal-chemical (ETC) ignition systems have been demonstrated in gun systems to provide desirable characteristics including reproducible shorter ignition delays. The optimum combination of capillary tube and fuse wire properties has not been identified yet. We present a combined theoretical and experimental study of the capillary discharge with an aim to develop a capillary plasma source with efficient energy conversion. The major emphasis in the present capillary discharge model is the ... |
|
| Heat Generation During the Firing of a Capacitor Based Railgun System |
2006 |
10 pages |
| Authors:
Andrew N. Smith; Benjamin T. McGlasson; Jack S. Bernardes; NAVAL ACADEMY ANNAPOLIS MD DEPT OF MECHANICAL ENGINEERING
|
| Railguns use a high-current, high-energy electrical pulse to accelerate projectiles to hypersonic velocities. Pulse forming networks that employ capacitors as the energy store are typically used to shape the required electrical pulse. A significant fraction of the stored energy (25 40% in large caliber railguns) is converted to projectile kinetic energy during launch. After the projectile exits the launcher, the balance of the energy has either been dissipated as heat ... |
|
| Leakage Reduction for On-Die Caches |
OCT 2005 |
34 pages |
| Authors:
Kaushik Roy; PURDUE UNIV LAFAYETTE IN SCHOOL OF ELECTRICAL AND COMPUTER ENGINEERING
|
| Technology scaling is associated with exponential increase in leakage for every subsequent technology generation. Since cache memories take up a significant portion of the die in modern processors, leakage contributes largely to power dissipation in caches. Our effort was to reduce leakage in large caches. We investigated several leakage-tolerant co-design techniques at the circuit and architecture levels. We also considered the effectiveness of the proposed techniques with predictive scaled devices. ... |
|
| Numerical Simulation of Galvanic Corrosion Caused by Shaft Grounding Systems in Steel Ship Hulls |
07 SEP 2005 |
|
| Authors:
Y. Wang; DEFENCE RESEARCH AND DEVELOPMENT ATLANTIC DARTMOUTH (CANADA)
|
 | The shaft grounding systems used on board HMC ships have substantially reduced the shaft-to-hull resistance and, thus, improved the performance of the shipboard impressed current cathodic protection (ICCP) system. Under some circumstances, however, the shaft grounding systems have been left on while the ICCP system was turned off. This led to the accelerated corrosion of the exposed steel ship hull on paint holidays because of the substantial difference of the ... |
|
| A Microchip Ring Trap for Cold Atoms |
05 SEP 2005 |
11 pages |
| Authors:
M. B. Crookston; P. M. Baker; M. P. Robinson; AIR FORCE RESEARCH LAB HANSCOM AFB MA
|
| We describe a method to create a circular magnetic waveguide for deBroglie waves on a microchip. The guide is a two-dimensional magnetic minimum for trapping weak-field seeking states of atoms or molecules with a magnetic dipole moment. It is created completely by electric currents in wires that are lithographically patterned on a multi-level chip. We describe the geometry and time-dependent currents of the wires and show that it is possible ... |
|
| Development of Increased Reliability Vertical Cavity Surface Emitting Laser Arrays |
AUG 2005 |
3 pages |
| Authors:
Keith Goossen; DELAWARE UNIV NEWARK
|
| Vertical Cavity Surface Emitting Lasers (VCSELs) should see increasing use for short distance optical interconnects in the next 5-10 years: data rate requirements will exceed 10 Gbit/second. It was shown in the proposal that at these data rates electrical current requirements on the VCSELs cause excessive failure rates due to current mitigated defect formation and thermal rise in the active region. Here the thermal rise is addressed through reduction of ... |
|
| A Counterpulsed, Solid-State Opening Switch |
JUN 2005 |
48 pages |
| Authors:
Michael Graham; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Railguns have great potential in military roles; however, they currently lack a fieldable power supply. Recent advances in the state of low voltage power storage devices may enable practical Pulse Forming Inductive Network power supplies to be developed if a suitable current interruption device is developed. A solid-state device in a counterpulsed opening switch configuration is a possible solution. A demonstration counterpulsed solid-state opening switch was constructed and successfully tested. ... |
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| Electrochemical Study of Corrosion Phenomena in Zirconium Alloys |
JUN 2005 |
134 pages |
| Authors:
Nicole M. Treeman; MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF NUCLEAR ENGINEERING
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| Shadow corrosion of zirconium alloy fuel cladding in BWR environments, the phenomenon in which accelerated corrosion is experienced when the cladding surface is in close proximity to other metals, has become a potentially life-limiting issue for BWR fuel. Recent results from experimentation at MIT, Halden, and Studvik suggest that a galvanic coupling drives the phenomenon between the cladding and the adjacent material. However, the actual processes involved are not understood. ... |
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| Bio-Inspired Concepts: Studies of Biological Response to External Electric Fields for Cellular Manipulation and Diagnostics - Modeling and Experimentation |
03 MAY 2005 |
34 pages |
| Authors:
Ravindra Joshi; OLD DOMINION UNIV RESEARCH FOUNDATION NORFOLK VA
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| A comprehensive modeling and experimental effort was carried out to develop an understanding of cellular bio-response to short duration, high- intensity electric fields. Macroscopic models for determining the time-dependent spatially-variable electric potential and current flows at single cells were developed. This provides predictions of both transmembrane voltages and temperature changes. The macroscopic model was coupled to a nano-simulator to probe the sub-cellular response at the molecular level. Many of the ... |
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| Mechanistic Studies Investigating the Role of Organophosphate Insecticide Exposure in the Development and Exacerbation of Asthma |
APR 2005 |
24 pages |
| Authors:
Ernst W. Spannhake; JOHNS HOPKINS UNIV BALTIMORE MD
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| This grant proposed to determine whether organophosphate insecticides act upon the cholinergic system in the lungs increasing cholinergic neurotransmission and causing airway hyperresponsiveness, a key characteristic of asthma. Guinea pigs were treated with the organophosphate insecticides, chlorpyrifos, diazinon and parathion. Electrical stimulation of the vagus nerves caused frequency-dependent bronchoconstriction that was used to assess the state of reactivity of the airways. Pharmacologic agents were used to define the roles that ... |
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ELECTRIC CURRENT
