| Emergence of Dissipative Structures in Current-Carrying Superconducting Wires (Postprint) |
26-May-2009 |
13 pages |
| Authors:
G A Levin; P N Barnes; J S Bulmer; J P Rodriguez; J A Connors; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH PROPULSION DIRECTORATE
|
 | We discuss the emergence of a spontaneous temperature and critical current spatial modulation in current-carrying high-temperature superconducting wire. The modulation of the critical current along the wire on a scale of 3-10 mm forces a fraction of the transport current to crisscross the resistive interface between the superconducting film and normal metal stabilizer attached to it. This generates additional heat that allows such structure to be self-sustainable. Stability and the ... |
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| The Interpretation of Motionally Induced Electric Fields in Oceans of Complex Geometry |
01-Oct-2008 |
192 pages |
| Authors:
Zoltan B Szuts; WASHINGTON UNIV SEATTLE APPLIED PHYSICS LAB
|
| Sea water moving through the earth's magnetic field induces electric currents in the ocean, and in general their distribution depends on the 3D structure of the ocean and its surroundings. Although velocity is traditionally calculated from measurements of the electric field with a one-dimensional relationship in the vertical, higher dimension processes are expected near steep topography or in energetic and variable flows. The observational capabilities of recently developed electric field ... |
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| Spatially Resolved Photocurrent Mapping of Operating Organic Photovoltaic Devices Using Atomic Force Photovoltaic Microscopy |
Jan-2008 |
7 pages |
| Authors:
B J Leever; M F Durstock; M D Irwin; A W Hains; T J Marks; L S Pingree; M C Hersam; NORTHWESTERN UNIV EVANSTON IL OFFICE OF RESEARCH SPONSORED PROJECTS
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| A conductive atomic force microscopy (cAFM) technique, atomic force photovoltaic microscopy (AFPM), has been developed to characterize spatially localized inhomogeneities in organic photovoltaic (OPV) devices. In AFPM, a biased cAFM probe is raster scanned over an array of illuminated solar cells, simultaneously generating topographic and photocurrent maps. As proof of principle, AFPM is used to characterize OPVs, revealing substantial device to device and temporal variations in the short-circuit current. The ... |
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| Dependence of Electron Peak Current on Hollow Cathode Dimensions and Seed Electron Energy in a Pseudospark Discharge (Preprint) |
03 JUN 2007 |
25 pages |
| Authors:
S. O. Cetiner; P. Stoltz; P. Messmer; Jean-Luc Cambier; TECH-X CORP BOULDER CO
|
| The pre-breakdown and breakdown phases of a pseudospark discharge are investigated using the two-dimensional kinetic plasma simulation code OOPIC Pro. Trends in the peak electron current at the anode are presented as function of the hollow cathode dimensions and mean seed injection velocities at the cavity back wall. The plasma generation process by ionizing collisions is examined, showing the effect on supplying the electrons that determine the density of the ... |
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| Multiphysics Modeling of Electric-Swing Adsorption System with In-Vessel Condensation (POSTPRINT) |
APR 2007 |
18 pages |
| Authors:
Menka Petkovska; Danijela Antov-Bozalo; Ana Markovic; Patrick D. Sullivan; BELGRADE UNIV (YUGOSLAVIA)
|
| Mathematical modeling of an Electric-Swing Adsorption (ESA) system (adsorption cycle with electrothermal desorption step, performed by direct heating of the adsorbent particles by passing electric current through them), with annular, radial-flow, cartridge-type fixed-bed and invessel condensation, is performed by using Comsol Multiphysics software. Three multiphysics models are built, in order to describe three stages of a compete ESA cycle: adsorption, electrothermal desorption before the start of condensation and electrothermal desorption ... |
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| Electromigration Related Effects At Metal-Metal Interfaces: Application To Railguns |
MAR 2007 |
75 pages |
| Authors:
Jr Cleveland William B.; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This thesis had 2 objectives. The first purpose of this thesis was to develop an experimental procedure to study electric current induced flow of liquid metal, similar to that found at the armature-rail contact due to local melting, to determine the kinetics of liquid flow Ga under electric current conditions. For this, a model system comprising a bead of Ga on a Cu thin film track was devised in order ... |
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| Platform Technologies for Minimally Invasive Physiological Monitoring |
01 NOV 2006 |
9 pages |
| Authors:
Mingui Sun; Steven A. Hackworth; Zhide Tang; Jun Zhao; Daliang L. Li; Sharon E. Enos; Brian Errigo; Gary Gilbert; Ronald Marchessault; Sylvain Cardin; PITTSBURGH UNIV PA
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| Two critical problems exist in the engineering design of minimally invasive implantable devices: power supply and communication. Without solving these two problems, implantable devices will not be able to exchange information with the outside world and operate for extended periods of time. Currently, there exist only limited approaches to these problems. Inspired by the power delivery mechanisms of electric fish, we have developed a bio-mimetic approach using the volume conduction ... |
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| Spin-Polarized Tunneling at Interfaces Between Oxides and Metals or Semiconductors |
SEP 2006 |
50 pages |
| Authors:
Douglas J. Strand; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
|
| Spin-polarized tunneling is a way to create a new type of electric current whose two driving forces are spin momenta rather than opposite charges. Much research has been done with this idea and that research has been reviewed and developed to propose an experimental program to use this new type of current to devise such electronic devices as the Datta-Das spin field-effect transistor (SFET), the magnetic bipolar transistor, the hot-electron ... |
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| Conduction Properties of Microscopic Gold Contact Surfaces |
28 SEP 2005 |
9 pages |
| Authors:
Joseph Tringe; Warren G. Wilson; Jack E. Houston; AIR FORCE RESEARCH LAB KIRTLAND AFB NMSPACE VEHICLES DIRECTORATE
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| Electroplated gold surfaces of the type used for MEMS switches were surveyed by atomic force microscopy (AFM) to define the surface topographical features, and by x-ray photoelectron spectroscopy (XPS) to determine the chemical composition of the contact surface. The gold surfaces were contacted with electrochemically sharpened gold and tungsten probes using an interface force microscope (IFM), capable of simultaneously measuring contact currents from 10 fA to 10 mA and forces ... |
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| Overview of the Equatorial Electrojet and Related Ionospheric Current Systems |
24 AUG 2005 |
75 pages |
| Authors:
John P. Casey; NAVAL UNDERSEA WARFARE CENTER DIV NEWPORT RI
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| The equatorial electrojet (EEJ) is an intense electric current that flows in the ionosphere in a narrow zone above the magnetic dip equator during the daytime. The electrojet current produces a large enhancement of the surface component of the geomagnetic field at and in the vicinity of the dip equator. The EEJ is most intense around local noontime and appears to be more stable than other ionospheric current systems. This ... |
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| Pretreatment Capabilities and Benefits of Electrocoagulation |
DEC 2004 |
67 pages |
| Authors:
Michael Mickley; MICKLEY AND ASSOCIATES BOULDER CO
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| The goals of the research project were 1) to demonstrate the removal capabilities of the electrocoagulation (EC) technology and 2) to define the best application of the technology within the context of providing pretreatment to reverse osmosis systems. |
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| Higher Order Geometrical Modeling and Higher Order Field/Current Modeling in FEM, MoM, and PO Simulations |
23 APR 2004 |
7 pages |
| Authors:
Branislav M. Notaros; Milan M. Ilic; Miroslav Djordjevic; MASSACHUSETTS UNIV DARTMOUTH DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
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| Higher-order, large-domain electromagnetic simulations are presented based on the finite element method (FEM), method of moments (MoM), and physical optics (PO). The simulations combine higher order geometrical modeling and higher order field/current modeling, which is referred to as double-higher-order modeling. The examples demonstrate that accurate and efficient FEM, MoM, and PO simulations require both higher-order geometrical flexibility for curvature modeling and higher-order basis functions for field/current modeling in the same ... |
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| Interpretation of the Current Signal Collected from Surface Barrier Discharge Electrodes |
07 APR 2004 |
2 pages |
| Authors:
D. Korzec; E. G. Finantu-Dinu; J. Engemann; WUPPERTAL UNIV (GESAMTHOCHSCHULE) (GERMANY F R)
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| The current signal measured at the grounded electrode of the surface barrier discharge (SBD) excited in the frequency range 1-10 kHz is typically distorted by electric circuitry oscillations in MHz range. Numerical techniques for extraction of the partial discharge (PD) current signals with duration in ns range are proposed. |
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| Tunneling Characteristics of an Electron-Hole Trilayer in a Parallel Magnetic Field |
31 OCT 2003 |
5 pages |
| Authors:
Y. Lin; E. E. Mendez; A. G. Abanov; STATE UNIV OF NEW YORK AT STONY BROOK
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| We have studied the tunneling properties of GaSb/AlSb/InAs/AlSb/GaSb heterostructures in which electrons- and boles accumulate in the InAs and GaSb regions respectively under a magnetic field parallel to the interlaces The low- temperature (T=4.2 K) zero-bias magnetoconductance has shown a behavior with field that evidences the two-dimensional character of both electrons and holes and that has allowed us to determine the hole density and the electron-hole separation. The observed field ... |
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| Quantum Coherent Electron-Phonon Nanolaboratories |
30 AUG 2003 |
84 pages |
| Authors:
A. N. Cleland; CALIFORNIA UNIV REGENTS SANTA BARBARA OFFICE OF RESEARCH
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| This project was aimed at creating mechanically suspended nanostructures that include active electronic devices, with the goal of achieving coherence between electrons and vibrational phonons. We pursued separately the use of metal tunnel junctions (515 tunnel junctions and single- electron transistors, SETs), and electrostatically defined double quantum dots, as the electronic system. We performed cryogenic measurements with varying degrees of success. Due to unanticipated difficulties, the focus shifted direction several ... |
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| Taser Area Denial Device: A Human Effects Review |
MAR 2003 |
13 pages |
| Authors:
Daniel L. Gonzalez; Roxanne Constable; Clifford J. Sherry; Thomas Dayton; B. J. Klauenberg; CONCEPTUAL MINDWORKS INC SAN ANTONIO TX
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| The Taser Area Denial Device (TADD) is a non-lethal alternative to anti-personnel landmines and is a concept based on Taser technology. Specifically, the TADD is based on electronic components manufactured and sold by TASERTRON, who exclusively manufactures laser products for law enforcement agencies. The concept is not commercially available and is early in its developmental stage. The TADD should incapacitate an individual without causing any acute or long term injury ... |
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| Spacecraft Power Beaming and Solar Cell Annealing Using High-Energy Lasers |
DEC 2002 |
94 pages |
| Authors:
Richard C. Luce Jr.; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF AERONAUTICS AND ASTRONAUTICS
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| Satellite lifetime is often limited by degradation of the electrical power subsystem--radiation-damaged solar arrays and failed batteries, Being able to beam power from terrestrial sites could alleviate this limitation, extending the lifetime of billions of dollars of satellite assets, as well as providing additional energy for electric propulsion that can be used for stationkeeping and orbital changes In addition, laboratory research at the Naval Postgraduate School (NPS) has shown the ... |
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| Surface Heating of Molybdenum, Tantalum, and Tungsten Rods by Pulsed Currents |
NOV 2002 |
40 pages |
| Authors:
Charles R. Hummer; John D. Powell; Paul R. Berning; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
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| Measurements of the surface voltage and surface temperature are made for small molybdenum, tantalum, and tungsten rods that have been subjected to pulsed electrical heating. The heating time is from 100 to 200 microseconds. The experimental results are then compared to results obtained from calculations undertaken with a numerical model that accounts for diffusion of current and ohmic heating within the sample. Good agreement between theory and experiment is obtained ... |
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| Flowing Electron Plasmas as Modified Current Source |
24 JUN 2002 |
10 pages |
| Authors:
Haruhiko Himura; Chihiro Nakashima; Haruhiko Saito; Zensho Yoshida; Junji Morikawa; TOKYO UNIV (JAPAN) GRADUATE SCHOOL OF FRONTIER SCIENCES
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| Probing of streaming electron plasmas with finite temperature is studied. Due to the fast flow of the electron plasmas, the characteristic curve spreads out significantly and exhibits a long tail. Another significant feature of the characteristic is that it determines a floating potential where the current equals zero, despite there being very few ions in the electron plasma. A high impedance probe, which is popularly used to determine the space ... |
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| Accuracy of Currents Produced by the Locally-Corrected Nystrom Method and the Method of Moments when used with Higher-Order Representations |
03 APR 2002 |
10 pages |
| Authors:
Andrew F. Peterson; GEORGIA INST OF TECH ATLANTA SCHOOL OFELECTRICAL AND COMPUTER ENGINEERING
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| The locally-corrected Nystrom method is described, and the accuracy of the currents produced by it and the method of moments are compared. Results suggest that when the underlying representation has the same degree, the methods are comparable in accuracy. Additional results are presented to illustrate the Nystrom approach, and advantages and disadvantages of the method are reported. |
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| Radiation Effects on Multi-Junction Solar Cells |
DEC 2001 |
90 pages |
| Authors:
Tommy L. Fifer; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| The GaInP2/GaAs/Ge monolithic high efficiency triple junction cell is the state of the art multijunction solar cell for space applications. Numerous labs have undertaken investigation into the stability of GaInP2/GaAs/Ge in response to electron radiation. Electron radiation experiments have shown that the degradation of GaInP2/GaAs/Ge solar cells is mainly caused by a decrease of the short circuit current (Isc). The investigation and interpretation of the damage mechanism from electron irradiation ... |
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| Recognition of Lower Limb Movements by Artificial Neural Network for Restoring Gait of Hemiplegic Patients by Functional Electrical Stimulation |
25 OCT 2001 |
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| Authors:
T. Watanabe; S. Yamagishi; H. Murakami; N. Furuse; N. Hoshimiya; TOHOKU UNIV SENDAI (JAPAN) INFORMATIONSYNERGY CENTER
|
 | This study focused on the man-machine interface of functional electrical stimulation (FES) systems for restoring the gait of hemiplegic patients. A method of recognition of lower limb movements using an artificial neural network (ANN) was examined in monitoring restored motions and in giving control command with 5 neurologically intact males, 22 to 24 years of age, and a female hemiplegic patient who was 55 years old. Acceleration signals were measured ... |
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| Computer Simulation of Electrical Propagation in Cardiac Tissue |
25 OCT 2001 |
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| Authors:
T. Arafune; A. Mishima; E. Kobayashi; I. Sakuma; H. Inada; TOKYO UNIV (JAPAN)
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| The purpose of the present research is to analyze the behavior of the reentrant spiral wave, which is one of the main causes of sudden cardiac death using computer simulation models of cardiac excitation propagation, The simulation model is a two dimensional electric circuit network model where many electric circuit models of cardiac membrane action potential were connected with electric resistance standing for intra-and extra cellular conductance, As cardiac membrane ... |
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| Adaptive Wave Motion Electrical Power Generator |
25 JUL 2001 |
13 pages |
| Authors:
Terrence E. Beal; DEPARTMENT OF THE NAVY WASHINGTON DC
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| An adaptive wave motion electrical power generation method and system are provided. An alternator, floating freely at a water's surface, has magnet and wire coil structures that undergo relative movement therebetween in response to wave motion at or near the water's surface thereby causing electric current to flow through the wire coil structure. Dynamic parameters (e.g., relative acceleration, velocity or displacement) describing the relative movement between the magnet and wire ... |
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| Search for Plasma Instability Driven THz Radiation Source |
12 APR 2001 |
11 pages |
| Authors:
E. Gornik; G. Strasser; M. Kast; C. Pacher; R. Zobi; TECHNISCHE UNIV VIENNA (AUSTRIA) INST FUER FESTKOERPERELEKTRONIK
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| IN RESONANT TUNNELING DIODES WITH VERY LONG EMITTER DRIFT REGIONS AN ADDITIONAL STRONG CURRENT PEAK IS OBSERVED AND ATTRIBUTED TO INTERSUBBAND TRANSITIONS MEDIATED BY THE RESONANT EMISSION OF INTERSUBBAND PLASMONS. This is the first direct proof of the mechanism proposed in the project for plasmon generation. Based on these findings new types of parabolic quantum wells were grown. The first structures consist of a parabolioc injector and an quantum well ... |
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| A Novel CMOS Photosensor With a Gate-Body Tied NMOSFET Structure |
JUL 2000 |
8 pages |
| Authors:
Youn-Jae Kook; Jae-Hun Jeong; Young-June Park; Hong-Shick Min; SEOUL NATIONAL UNIV (REPUBLIC OF KOREA) SCHOOL OF ELECTRICAL ENGINEERING
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| A novel CMOS photosensor with a gate-body tied NMOSFET structure realized in the triple well is presented. The photocurrent is amplified by the lateral and vertical BJT action, which results in two different output photocurrents, which can be used for different applications within a pixel. The lateral action results in the drain current with higher sensitivity at low light intensity. And the vertical action results in the collector current with ... |
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| Experimental Study on Fiber Bragg Grating Electric Current Sensor |
JUL 2000 |
3 pages |
| Authors:
Dejun Feng; Guiyun Kai; Lei Ding; Heliang Liu; Xiaoyi Dong; NANKAI UNIV TIANJIN (CHINA) INST OF MODERN OPTICS
|
| A new electric current sensor based on fiber Bragg grating tuned by giant magnetostrictive material rod is demonstrated in this paper. A fiber Bragg grating is firmly clung on a giant magnetostrictive rod that is put into the central pant of a solenoid, The Bragg wavelength of the fiber grating will shift when the uniform magnetic field in the solenoid changes. The rod will have elastic lengthening along the direction ... |
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| Tunneling Current Probe for Noncontract Wafer-Level Photodiode Array Testing |
DEC 1999 |
32 pages |
| Authors:
Horacio Verdun; Bruce McIntosh; FIBERTEK INC HERNDON VA
|
| The Tunneling Current Probe (TCP) is an automated picometer-sensitive proximity sensor and current measurement system which measures the current through a photodiode detector array element by establishing a tunneling current between a metallic probe tip and the detector element contact pad. The non- contact performance evaluation of infrared photodiode detector arrays at the wafer-level entails the measurement of the current versus voltage (I-V) characteristic of ... |
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| First Stroke Peak Current Characteristics for the United States |
06 OCT 1999 |
290 pages |
| Authors:
Gary Russell Huffines; TEXAS A AND M UNIV COLLEGE STATION
|
| The first stroke peak currents of over 105 million cloud to ground lightning flashes from 1995-1998 were analyzed over the continental Unites States (U.S.) landmass. The peak currents exhibit a variation based on season and geography, but positive flashes have different features than negative flashes. Several factors are considered when examining the peak current variations including latitudinal dependence, sensor separation in the National Lightning ... |
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| Current Instability and Disruption of Shaped-Charge Jets |
16 NOV 1998 |
67 pages |
| Authors:
G. A. Shvetsov; A. D. Matrosov; RUSSIAN ACADEMY OF SCIENCES NOVOSIBIRSK INST OF HYDRODYNAMICS (LAVRENTYEV) SIBERIAN DIV NOVOSIBIRSK
|
| The idea of electromagnetic action on a shaped-charge jet (SCJ) has a relatively long history. The first experiments familiar to the authors were performed under the guidance of M. A. Lavrentyev as early as 1957 1. In these experiments, small shaped charges (SC) of caliber 25 mm were used. A capacitor bank with a voltage of up to 50 kV was used as the electromagnetic energy ... |
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| Physical-and-Mathematical Model of Penetrators into Multilayer Media in the Presence of Large Pulsed Currents and Substantiate with Demonstration Experiments |
SEP 1998 |
47 pages |
| Authors:
A. F. Piskunkov; N. P. Shishaev; V. A. Obukhov; R AND D PLATONIK LTD MOSCOW (RUSSIA)
|
| Physical-and-mathematical model of interaction processes in cumulative jet (CJ) influenced by pulsed electric current as physical basis of electrodynamics armor (EDA) has been studied. Magnetohydrodynamics model of CJ with current has been formulated. The role of the current integral and the rate of the discharge current growth as the main factors influencing the penetration deepness decrease have been shown. The critical magnitudes of both parameters ... |
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| Method for Launching Projectiles with Hydrogen Gas. |
04 AUG 1998 |
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| Authors:
Woodrow W. Lee; Richard D. Ford; DEPARTMENT OF THE NAVY WASHINGTON DC
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| A method for propelling a projectile by applying a high power pulse of electrical current to a metal fuel element (of Al. Al-Li, or Al-Mg) causing the element to explode dispersing molten metal fuel into water with which it reacts to rapidly generate hydrogen gas at high pressure, the hydrogen gas is used to push the projectile. After the peak current is reached, an inductive electrical energy source drives the ... |
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| Influence of Electric Currents and Fields on the Kinetics and Microstructure of Phase Transformations in Metals and Ceramics |
15 OCT 97 |
30 pages |
| Authors:
Hans Conrad; NORTH CAROLINA STATE UNIV AT RALEIGH DEPT OF MATERIALS SCIENCE AND ENGINEERING
|
| Electropulsing: The decrease in the flow stress of FCC metals produced by individual high density electropulses was mainly due to an increase in the pre-exponential in the Arrhenius rate equation for plastic flow. An order of magnitude decrease in the colony size of eutectic Pb-Sn castings was produced by electropulsing, the effect being in accord with an increased nucleation rate. Electropulsing caused the precipitation of nanometer alpha-Fe particles from the ... |
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| Cryogenic Aluminum Armature Bar For High Power Generators |
AUG 97 |
95 pages |
| Authors:
Lidia Chubraeva; INSTITUTE FOR ELECTROTECHNICAL PROBLEMS ST PETERSBURG (RUSSIA)
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| This report results from a contract tasking Institute for Electrotechnical Problems (NIIElectromash) as follows: The contractor shall fabricate an aluminum cryogenic armature bar for high power generators, fabricate a specialized test fixture for evaluation of the armature bar and assemble the armature bar in the test fixture and test in appropriate cryogens to determine performance at a variety of temperatures. Test currents and voltages shall be applied to the armature ... |
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| Microfabrication of a Mechanically Controllable Break Junction in Silicon |
21 AUG 1995 |
4 pages |
| Authors:
C. Zhou; C. J. Muller; M. R. Deshpande; J. W. Sleight; M. A. Reed; YALE UNIV NEW HAVEN CT CENTER FOR MICROELECTRONIC MATERIALS AND STRUCTURES
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| The authors present a detailed description of the microfabrication and operation at room temperature of a novel type of tunnel displacement transducer. Instead of a feedback system, it relies on a large reduction factor, assuring an inherently stable device. Stability measurements in the tunnel regime infer an electrode stability within 3 pm in a 1 kHz bandwidth. In the contact regime, the conductance takes on a discrete number of values ... |
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| Effects of Exercise and Exercise Combined with Electrical Stimulation on a Diastasis Recti: A Single Subject Design |
07 JUN 95 |
76 pages |
| Authors:
Kerry L. Sitler; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
|
| In the physical therapy management of the obstetrical patient, the opportunity to effectively evaluate and treat associated musculoskeletal dysfunction is gaining popularity. A common musculoskeletal condition found during and after pregnancy is a diastasis recti abdominis.1-4 The term diastasis simply means separation of. Many researchers believe that this separation occurs secondary to the softening of connective tissues related to the hormonal releases of progesterone and relaxing, and to the prolonged ... |
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| Room-Temperature Photocurrent Spectroscopy of GaAs/GaAlAs Multiple Quantum Wells |
15 NOV 94 |
16 pages |
| Authors:
Hailong Duan; Qiuning Wang; NATIONAL AIR INTELLIGENCE CENTER WRIGHT-PATTERSON AFB OH
|
| By means of room temperature photocurrent spectroscopy, we have studied the effect of electric fields on exciton absorption in GaAs/ GaAlAs multiple quantum wells (MQW) and discuss in this paper the effect of an electric field on the photocurrent spectra for some kinds of MWQ structures. The material requirement for related optoelectric devices MQW is also discussed. (jg) ANNOTATION: Room-Temperature Photocurrent Spectroscopy of GaAs/GaA1As Multiple Quantum Wells. --Translation. |
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| Arcjet Diagnostics Using Current Modulation Velocimetry and Pulsed Electron Beam Fluorescence |
JUN 1994 |
12 pages |
| Authors:
Jeffrey A. Pobst; John H. Schilling; Frederick M. Lutfy; Daniel A. Erwin; Ronald A. Spores; UNIVERSITY OF SOUTHERN CALIFORNIA LOS ANGELES DEPT OF AEROSPACE ENGINEERING
|
| New diagnostic techniques to measure the fundamental plasma properties of an arcjet are being developed collaboratively between the University of Southern California and Air Force Phillips Laboratory. The diagnostics described here are for measuring velocity and density, principal parameters that describe the plasma state within an arcjet. Velocity measurements are being obtained from a new technique we have named Current Modulation Velocimetry (CMV). A current spike applied to the arcjet ... |
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| Turn-On Transient Overcurrent Response Suppressor. |
26 OCT 1993 |
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| Authors:
Thomas I. Kirkpatrick; DEPARTMENT OF THE NAVY WASHINGTON DC
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| A turn-on transient overcurrent response suppressor is connected to an existing electrical circuit having a regulator circuit that includes an overcurrent protection mechanism. A first charging circuit is connected to the power supply for simultaneous charging therewith. A second charging circuit is connected to the first charging circuit for delayed charging therewith. Connected between the first and second charging circuits is a circuit to create a low impedance discharge path ... |
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| Method for Measuring the Resistive Transition and Critical Current in Superconductors using Pulsed Current. |
29 JUN 1993 |
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| Authors:
Wayne C. McGinnis; Thomas E. Jones; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| The present invention provides a method for measuring the intragranular and intergranular critical current of a granular superconductive material, comprising the steps of: (1) conducting a substantially rectangular electronic pulse through the material so as to conduct a current through the material such that when the intergranular critical current of the material is exceeded, any grains present in the material remain in a superconducting state when the current level is ... |
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| Integrated Fundamental Research on Current Collection |
JUN 93 |
53 pages |
| Authors:
Doris Kuhlmann-Wilsdorf; Leo Tran; VIRGINIA UNIV CHARLOTTESVILLE SCHOOL OF ENGINEERING AND APPLIED SCIENCE
|
| The aim of our research was to add to the basic understanding in the area of current collection with particular emphasis on topics likely to benefit practical objectives. Under sponsorship of this contract, 23 papers were published in the international literature. Additionally, 13 invited lectures and 11 contributed lectures on various aspects of this research were delivered at universities, research laboratories, and international conferences by the principal investigator and coworkers. ... |
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| On the Ideality of Using a Step-Function Current in a Metallic Foil to Simulate a Step-Function Heat-Flux Source |
MAY 93 |
23 pages |
| Authors:
Martin S. Miller; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| An exact solution is derived to the one-dimensional, time-dependent, heat-conduction equation for a two-layer, semi-infinite, composite solid with sudden uniform heat generation in the surface layer, no heat transfer through the surface plane, and uniform initial temperature. The interface between the two layers is assumed to have no thermal contact resistance. This solution enables a discussion of the ideality with which a step-function electric current in a metallic foil can ... |
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| Microwave Interaction with Plasmas |
30 APR 93 |
21 pages |
| Authors:
Igor Alexeff; Mark Radar; TENNESSEE UNIV KNOXVILLE
|
| The object of this work is to create dense plasmas for research military, and industrial development that are accessable - and not confined in vacuum systems. The corona method of production by high D.C. and A.C. voltages is simple and convenient. Much work was done in this field in the 1900-1940 time frame, but the field seems to be neglected now. Multiple points were used on positive and negative electrodes ... |
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| Electromagnetic Diffusion and Wire Coupling |
APR 93 |
107 pages |
| Authors:
Bart Goldstein; Rudolf Goldflam; MISSION RESEARCH CORP SANTA BARBARA CA
|
| This report documents the research performed to develop physical insight into the coupling of radiated, pulsed, electromagnetic energy to a thin wire located inside a rectangular metallic en sure. The electromagnetic fields diffuse into the rectangular cavity. The cavity size is not small compared to the wavelengths in the exciting field. A prime objective was to determine how the wire transients will change due to the parameters of cavity size, ... |
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| Development of Diagnostics for Electromagnetic Armor Applications |
JUN 92 |
36 pages |
| Authors:
Charles R. Hummer; Clinton E. Hollandsworth; ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| A test stand consisting of an electrified-plate assembly coupled to a small capacitor bank has been assembled, tested, and used to develop diagnostic instrumentation to be exploited in future range experiments in the general area of electromagnetic technology applied to terminal ballistics. A 1.2-m-long air gun is used to propel a length of copper wire through small holes in the electrified-plate assembly to simulate the switch-closure action important to some ... |
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| Proposal for a Workshop in the Physics and Application of Hollow Electrode Glow Switches |
06 DEC 91 |
26 pages |
| Authors:
Martin Gundersen; UNIVERSITY OF SOUTHERN CALIFORNIA LOS ANGELES DEPT OF ELECTRICAL ENGINEERING AND ELECTROPHYSICS
|
| The purpose of the 1989 NATO ARW was to develop applications for and an improved understanding of the physics for high current emission and conduction observed in hollow cathode-hollow anode switches including the pseudospark and back-lighted thyratron (BLT). New applications include highly emissive cathodes for microwave devices, accelerators and free electron lasers, high power tubes, electron and ion-beams, microlithography. accelerators, and other plasma devices. Recent research has produced this new ... |
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| Effect of Electromagnetic Fields on the Stability of a Perfectly Conducting, Axisymmetric Shaped-Charge Jet |
JUN 90 |
28 pages |
| Authors:
John D. Powell; David L. Littlefield; ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| The stability characteristics of a shaped-charge jet which carries an electrical current are investigated. The jet is assumed to be perfectly plastic, perfectly conducting, and axisymmetric. The equations which govern the behavior of the jet are solved numerically using first-order perturbation theory, after the surface of the jet has been subjected to some arbitrary disturbance. The solution of these equations indicates that the jet is unstable. The growth rate of ... |
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| Very High Frequency Measurements of Geometric Factors in Transmission Line Lead Acid Cells |
15 MAR 90 |
31 pages |
| Authors:
B. D. Cahan; R. R. Adzic; M. L. Daroux; E. B. Yeager; CASE WESTERN RESERVE UNIV CLEVELAND OH DEPT OF CHEMISTRY
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| Strip-line cells using Lead strips 1 cm wide with Sulfuric Acid electrolyte have been constructed with lengths of 10 cm, 25 cm and 100 cm with several electrode spacing to test the predictions of the theoretical models under real cell conditions. The impedance of these cells has been measured over a wide frequency range (0.1 - 10 to the 7th power Hz). New experimental techniques had to be developed for ... |
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| Current Injection Pumping of Organic Light Emitters |
28 SEP 89 |
26 pages |
| Authors:
Jeffrey C. Buchholz; James P. Stec; Mary C. Schutte; MICRO-OPTICS TECHNOLOGIES INC MIDDLETON WI
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| The use of thin films of phthalocyanines as current pumped light emitters was investigated. The growth of phthalocyanine films in a stacked ring crystal structure offers the potential for introduction of electronic structure modulation in the film which could lead to charge carrier confinement and resultant optical emission. Heteroepitaxial stacked ring crystal structures could only be grown to a film thickness of 5 nanometers however. The metal phthalocyanines studied for ... |
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| Arc Current Control of a Robotic Welding System: Modeling and Control System Design |
SEP 89 |
53 pages |
| Authors:
Bruce W. Greene; ILLINOIS UNIV AT URBANA COORDINATED SCIENCE LAB
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| This research was conducted as part of a joint project for the University of Illinois and the Metallurgy and Quality Assurance Team of the United States Army's Construction Engineering Research Laboratory. The ultimate objective of the program is to develop an automated welding system that produces consistently good welds despite variations in material parameters and other disturbances. The scope of the research is limited to consumable-electrode gas metal are welding ... |
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