| Trajectory, Development, and Temperature of Spark Kernels Exiting into Quiescent Air (Preprint) |
Apr 2012 |
14 pages |
| Authors:
Barry V Kiel; David L Blunck; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH PROPULSION DIRECTORATE/TURBINE ENGINE DIVISION
|
 | An inverse deconvolution technique was developed to determine the temperature and sensible energy of the kernels. This technique is evaluated by a sensitivity analysis and comparisons to measurements on a well characterized flame. Infrared images show that the kernels develop into a toroidal shape after exiting from the igniter. The statistical distribution of the trajectory of spark kernels is symmetric. Buoyancy forces have a negligible effect on the trajectory. Regions ... |
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| Bio-Inspired Ceramic/Carbon Composites |
Jan 2012 |
6 pages |
| Authors:
Eduardo S Gutierrez; Mike Reece; Nicole Grobert; IMPERIAL COLL LONDON (UNITED KINGDOM)
|
| In line with the final objective to fabricate bio-inspired ceramic/CNT or ceramic/carbon composites with nacre-like structures by combining freeze casting with spark plasma sintering our work during this first half of the project has concentrated on the following aspects: a) Set-up a freeze casting apparatus for the controlled freezing of ceramic suspensions. b) Structural control of freeze casted materials in particular the lamellae/pore thickness and the structural macroscopic lamellae alignment. ... |
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| A Flexible Method for Production of Stable Atomic Clusters with Variable Size for Chemical and Catalytic Activity Studies |
Dec 2011 |
14 pages |
| Authors:
Michael D Barankin; Andreas Schmidt-Ott; DELFT UNIV OF TECHNOLOGY (NETHERLANDS)
|
| The goal was to set up a flexible source for production of atomic clusters with large production rate and to measure their superconducting transition temperature. We have set up a generator based on spark discharge electrode ablation and size selected the produced clusters by mobility classification. The size distributions were measured on samples of gallium and platinum atomic clusters. Total spark energy was found to have some effect on the ... |
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| Taguchi Analysis on the Effect of Process Parameters on Densification During Spark Plasma Sintering of HfB2-20SiC (Preprint) |
Nov 2011 |
13 pages |
| Authors:
Ravi K Enneti; Carmen M Carney; Seong-Jin Park; Sundar V Atre; UES INC DAYTON OH
|
| Field assisted sintering (FAST) has emerged as a useful technique to densify ultra high temperature ceramics like HfB2- 20SiC to a high density at relatively low temperatures and shorter times. The effect of various process variables on the densification during spark plasma sintering of HfB2-20SiC was studied using Taguchi analysis. The statistical analysis identified sintering temperature as the most significant parameter affecting the densification of HfB2-20SiC material. A density of ... |
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| Mechanism of Electro-Static Discharge (ESD) Sensitivity of Reactive Powders and Its Mitigation |
14 MAR 2011 |
115 pages |
| Authors:
Edward L. Dreizin; Ervin Beloni; NEW JERSEY INST OF TECH NEWARK
|
| Electrostatic discharge (ESD) ignition of Mg, Al, and Ti powders is studied experimentally. Discharge energy is quantified by real time measurements of current and voltage; ignition behavior of powders is studied optically. A fraction of ESD energy transferred to powder is determined for different experimental configurations. It is shown that powder heating by ESD is adequately described considering Joule energy produced by the ESD current. Powder heating occurs adiabatically. For ... |
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| Empirical Characterization of Ballistic Impact Flash |
MAR 2011 |
96 pages |
| Authors:
Thomas P. Talafuse; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
|
| Fires onboard aircraft are leading mechanisms for mishaps and losses during peacetime and combat operations. Typical ignition sources causing fires onboard aircraft include electrical sparks and hot surfaces. However, impact and penetration of common threats encountered during combat operations, such as armor piercing incendiary projectiles and missile fragments, generate short-lived, but thermally-intense clouds (flashes) capable of igniting fires. Fire simulations supporting system-level survivability analyses depend on accurate characterization of these ... |
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| Aero-Optic Measurements Using a Laser-Induced Air Breakdown Beacon (PrePrint) |
04-Jun-2009 |
14 pages |
| Authors:
Matthew Whiteley; R Rennie; Garnett Cross; David Goorseky; David Cavalieri; Eric J Jumper; MZA ASSOCIATES CORP DAYTON OH
|
| An experimental investigation into the optical behavior of a laser-induced air breakdown spark is described. The investigation concentrates on qualities of the air-breakdown spark, particularly the non-point-source character of the spark, that have a critical influence on the accuracy with which aero-optic aberration can be measured using the return light from the spark. Data are presented that show that the spark dimensions conform to established physical models, and baseline spark ... |
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| Global Climate Change: National Security Implications |
2007 |
5 pages |
| Authors:
II Johnson Douglas V.; ARMY WAR COLL STRATEGIC STUDIES INST CARLISLE BARRACKS PA
|
| Climate change is underway. The effects will vary according to a broad variety of circumstances and interactions, some of which are not well-understood. Likewise, mitigation is not wellunderstood, and will not take place quickly. The national security implications of climate change are proportional both to the speed of change and the extent. Public awareness should follow a coordinated strategic communication plan that focuses on maintaining credibility. Threats to national survival ... |
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| Status Report on SPS TiB2/TiB/Ti Functionally Graded Materials (FGMs) for Armor |
SEP 2006 |
26 pages |
| Authors:
James W. McCauley; G. D'Andrea; Kyu Cho; Matthew S. Burkins; Robert J. Dowding; Jr Gooch William A.; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
|
| The pioneering research by Wilkins and colleagues in the 1960s led many investigators to conclude that ceramic armor performance could be significantly enhanced with materials macrostructurally designed to grade from a pure ceramic to a stiff, more ductile material at the back surface. Several configurations of TiB2/TiB/Ti functionally graded materials were fabricated using a spark plasma sintering process. Detailed microstructural characterization of the as-processed material is presented as well as ... |
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| Characterization of Pulse Detonation Engine Performance with Varying Free Stream Stagnation Pressure Levels |
MAR 2006 |
172 pages |
| Authors:
Wesley R. Knick; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| A pulse detonation engine operates on the principle that a fuel-air mixture injected into a tube will ignite and undergo a transition from a deflagration to a detonation and exit the tube at supersonic velocities. Studies in the field of combustion have shown that both ignition time and deflagration to detonation transition time can vary as a function of pressure. It can be hypothesized that if ignition and deflagration to ... |
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| Temporal Evolution of the LIBS Spectrum of Aluminum Metal in Different Bath Gases |
DEC 2004 |
30 pages |
| Authors:
Thuvan N. Piehler; Frank C. DeLucia Jr.; Chase A. Munson; Barrie E. Homan; Andrzej W. Miziolek; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
|
| The spectral emission of gas phase aluminum (Al) and Al oxide was measured during and immediately after exposure of a bulk Al sample to a laser- induced spark produced by a focused. pulsed laser beam (Nd:YAG, 10 ns pulse duration, 35 mJ/pulse lambda = 1064 nm). The spectral emission was measured as a function of time after the onset of the laser pulse. and was also measured in different bath ... |
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| Plasma Control of Separated Flows on Bodies of Revolution at High Angles of Attack |
DEC 2004 |
61 pages |
| Authors:
Boris Y. Zanine; RUSSIAN ACADEMY OF SCIENCES NOVOSIBIRSK INST OF THEORETICAL AND APPLIED MECHANICS
|
| This report results from a contract tasking Institute of Theoretical and Applied Mechanics as follows: This proposal deals with surface discharge plasmas and other plasma devices to quench stall-slip departure due to 1) asymmetric vortex shedding on conical body nose tips, and 2) augment directional control/authority. In spite of the extensive work in this area, limited understanding of the underlying basic physical processes near body nose tips as they pertain ... |
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| Spontaneous Branching of Anode-Directed Discharge Streamers: Conformal Analysis and Numerical Results |
20 JUL 2003 |
2 pages |
| Authors:
U. Ebert; B. Meulenbroek; C. Montijn; A. Rocco; W. Hundsdorfer; EINDHOVEN UNIV OF TECH (NETHERLANDS)
|
| We recently have identified a simple mechanism of spontaneous streamer branching 1, 2. Here we discuss when this instability occurs, we present new numerical results, and we present a reduced model in which the instability can be studied analytically. |
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| Localized Flow Control With Energy Deposition |
OCT 2002 |
361 pages |
| Authors:
Russel G. Adelgren; RUTGERS - THE STATE UNIV NEW BRUNSWICKNJ
|
| A series of experiments with energy deposition via laser-induced optical breakdown of air, i.e., a laser spark, have been performed. These experiments have demonstrated the possibility of using a laser spark for supersonic flow control. A focused Nd:YAG laser (pulse time of 10 nanoseconds, pulse frequency of 10 Hz, and capable of energy levels up to 600 milli-Joules per pulse) was used to create the energy deposition laser spark. This ... |
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| Further Development of the Spark Tracing Technique for Flow Visualization |
JUL 2002 |
|
| Authors:
V. M. Boiko; V. I. Zapryagaev; V. I. Kornilov; A. P. Petrov; A. V. Solotchin; RUSSIAN ACADEMY OF SCIENCES NOVOSIBIRSK INST OF THEORETICAL AND APPLIED MECHANICS
|
 | The spark tracing technique allows one to measure both steady-state and non-steady flows and reveal their characteristic features such as shock waves flow separation regions reverse-flow regions etc. Setting with precise accuracy tie interval between spark discharges and measuring distance between successive photographed images of spark-discharge channels enable one to built the flow velocity field in the flow region covering by sparks. The present study was aimed at further development ... |
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| An Investigation Into the Aerodynamics and Structural Integrity of the 155-mm M898 Projectile |
NOV 1999 |
27 pages |
| Authors:
Keith P. Soencksen; Vural Oskay; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS TECHNOLOGY DIRECTORATE
|
| The M898 sense-and-destroy armor (SADARM) projectile is a 155-mm counterbattery artillery projectile that ejects two submunitions against battlefield combat vehicles. The U.S. Army Armament Research, Development, and Engineering Center (ARDEC) recently funded an experiment designed to analyze the structural integrity and aerodynamic characteristics of the projectile. In particular, the experiment sought to investigate the possibility of a compromise in integrity at the base-body juncture. No evidence ... |
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| Field Emission Tube for a Mobile X-Ray Unit |
29 SEP 1998 |
12 pages |
| Authors:
Craig N. Boyer; Glenn E. Holland; John F. Seely; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| A field emission X-ray tube is provided for use in a mobile X-ray machine. An evacuated ceramic housing having a convoluted interior shape for dissipating sparks surrounds the components of the field emission tube. A cathode and, an anode which emits x-rays, are located within the ceramic housing. A hollow anode tube is connected to the anode at one end and a vacuum pinch off element at the other end. ... |
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| Functional Enhancements in Used Oil Analysis Spectrometers |
1998 |
7 pages |
| Authors:
Malte Lukas; Robert J. Yurko; SPECTRO INC LITTLETON MA
|
| Spark emission spectrometers using the rotating disk electrode (RDE) technique have become the workhorses and primary analytical tool of most machine condition monitoring programs based on oil analysis. This paper describes several new developments that have put new life into this established and well accepted used oil analysis technique. They include performance enhancements, automation and additional capabilities. Digital technology has been applied in the design of excitation sources, optical and ... |
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| System for Preventing Biofouling of Surfaces Exposed to Water. |
03 JUN 1997 |
|
| Authors:
Michael G. Grothaus; Michael S. Mazzola; Marianne Walch; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| Acousticai shock waves are generated by electrical sparks within a gap between electrodes adjustably positioned for exposure to water adjacent a surface immersed therein. High voltage electrical energy derived from a constant current power supply, is stored in a capacitor for rapid, application to the electrodes by discharge during cyclic periods of short duration under remote control in order to render the acoustical shock waves so generated effective in preventing ... |
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| Quantitative Analysis of the Detection Limits for Heavy Metal- Contaminated Soils by Laser-Induced Breakdown Spectroscopy |
JUN 1997 |
34 pages |
| Authors:
Dennis R. Alexander; Dana E. Poulain; NEBRASKA UNIV LINCOLN
|
| Laser-induced breakdown spectroscopy (LIBS) is a rapid remote measurement method for detection of metals in the environment. A major factor in the quantitative use of this technique involves the minimum detection limits under both laboratory and field operations. Research on limits of detection of heavy metals in different types of soils under various conditions using LIBS has been carried out under Contract DACA39-95-K-0053. Pulses from a Nd:YAG laser operating at ... |
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| Control of Acoustic Cavitation with Application to Lithotripsy |
03 MAR 97 |
221 pages |
| Authors:
Michael R. Bailey; TEXAS UNIV AT AUSTIN APPLIED RESEARCH LABS
|
| Control of acoustic cavitation (sound-induced bubble activity) is the subject of this dissertation. Application is to clinical lithotripsy where cavitation contributes to kidney stone comminution and tissue damage. An electrical spark at the near focus of an underwater ellipsoidal reflector was the acoustical source, as in the Dornier HM3 lithotripter. Experiments were done with rigid reflectors, pressure-release reflectors, and pairs of reflectors sharing a common focus and a controlled delay ... |
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| Laser-Induced Breakdown Spectroscopy on Solution Samples Using Surface Excitation |
DEC 96 |
112 pages |
| Authors:
Leonard M. Berman; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
|
| Laser-induced breakdown spectroscopy (LIBS) is a spectroscopic technique where output from a pulsed laser is focused onto a target in order to create an intense plasma. The optical emission is characteristic of the elements in the focal volume and can be used for elemental analysis. Research on the detection of nickel in solution in addition to solvent detection of CCl4, CHCl3, C2Cl4, and C2HCl3 has been performed. Breakdown was formed ... |
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| Quantitative Analysis of the Detection Limits for Heavy-Metal- Contaminated Soils by Laser-Induced Breakdown Spectroscopy |
31 JUL 96 |
37 pages |
| Authors:
Dennis R. Alexander; Dana E. Poulain; NEBRASKA UNIV LINCOLN DEPT OF ELECTRICAL ENGINEERING
|
| Laser-induced breakdown spectroscopy (LIBS) is a rapid remote measurement method for detection of metals in the environment. A major factor in the quantitative use of this technique involves the minimum detection limits under laboratory and field operations. Nd:YAG laser pulses (125 mJ, lambda = 1. 06 micrometers) are focused on sample surfaces to produce laser sparks (plasmas) . Plasma emissions are recorded after interference from broadband emissions is reduced. Results ... |
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| Optical Pseudospark Switch. |
21 MAR 1995 |
|
| Authors:
Michael G. Grothaus; Jack S. Bernardes; David C. Stoudt; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| This patent discloses a high voltage, high current, multichannel, optically-triggered switch with the potential for improved lifetime of operation. Triggering of the switch is accomplished by ultraviolet illumination of multiple cathode apertures via fiber optic cables. The trigger optics for each channel, being composed of a fiber-optic cable terminated by some collimating optics, are protected from damaging metalization by enclosing them in an angled metal or dielectric tubes in the ... |
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| ONR Basic Research Program: Summary and Bibliographies |
30 JAN 95 |
34 pages |
| Authors:
Thomas G. Muir; Elaine C. Hackert; TEXAS UNIV AT AUSTIN APPLIED RESEARCH LABS
|
| The Office of Naval Research (ONR) sponsors the Basic Research Program, a discretionary grant program for the purpose of giving university laboratory directors freedom to develop and apply their resources to basic research problems of naval relevance, which may not be known or appreciated by others in the community. Program guidelines include involvement of students and faculty and initiation of research in areas that could transition into either core or ... |
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| Aircraft Fuel System Lightning Protection Design and Qualification Test Procedures Development |
SEP 94 |
193 pages |
| Authors:
Keith E. Crouch; LIGHTNING TECHNOLOGIES INC PITTSFIELD MA
|
| The Navy and the Air Force recognized the need for improved test procedures for evaluating the lightning protection design of aircraft fuel systems. Under their sponsorship, a program to develop adjustable, standard ignition sources which could be used to calibrate techniques for detecting ignition sources during lightning testing was established. The minimum ignition levels of voltage sparks and hot spots were established under the program before it was terminated due ... |
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| Nanophase Materials Synthesis - Properties - Applications |
SEP 94 |
|
| Authors:
George C. Hadjipanayis; Richard W. Siegl; DELAWARE UNIV NEWARK DEPT OF PHYSICS AND ASTRONOMY
|
| Partial Contents: Chemical Synthesis of Nanophase Materials; Preparation of Gamma Fe2Oe Particles; Synthesis of III-V Semiconductor Particles from Organometallic Precursors; Synthesis of Nanostructured Catalysts and Catalytic Supports; Formation of Magnetic Spinel Iron Oxide in Solution; Synthesis of Nanoscale Iron Oxide Structures Using Protein Cages and Polysaccharide Networks; Gas Evaporation and Electron Microscopical Observation of Small Particles; Nanoparticles from a Supersaturated Vapor; Formation and Phase ANalysis of Surface Oxides on Ultrafine ... |
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| Cold-Start Minidiesel Engine Development |
SEP 93 |
32 pages |
| Authors:
Conrad Collins; ADVANCED MATERIALS INC METAIRIE LA
|
| Military mission performance in a chemically contaminated environment necessitates the wearing of chemically impermeable protective garments. Soldiers encapsulated in these protective garments will succumb to heat stress in a hot environment. Consequently, a microclimate cooling system is being developed. In the design, a vapor compression cycle chills water which is then circulated over the body to absorb heat via a cooling garment. The engine, the prime mover in the system, ... |
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| An Electronic Imaging System for the Aeroballistic Research Facility |
JUL 93 |
11 pages |
| Authors:
G. L. Winchenbach; D. B. Snyder; M. A. Valentino; H. C. Macke; W. J. Rowe; WRIGHT LAB EGLIN AFB FL ARMAMENT DIRECTORATE
|
| Until the present date, free-flight spark ranges have used conventional film technology for recording the position-attitude histories of the projectiles as they traversed the instrumented ranges. The purpose of this paper is to describe the plans for converting the existing film based camera system in the Aeroballistic Research Facility to an electronic imaging system based on modern charge coupled device (CCD) technology. The primary concern associated with this conversion has ... |
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| The Effects of Reverberant Impulse Noise (BLAST WAVES) on Hearing: Parametric Studies |
16 JUN 93 |
|
| Authors:
Roger P. Hamernik; STATE UNIV OF NEW YORK COLL AT PLATTSBURGH AUDITORY RESEARCH LAB
|
| This research is directed at studying the effects on the auditory system of exposure to high levels of reverberant impulse noise using an animal (chinchilla) model. The blast waves were generated by a three inch diameter shock tube (source III), which produced wave signatures having spectral energy concentrated in the 12 kHz region. The waves were discharged into a reverberant chamber within which animals were individually exposed. Animals were exposed ... |
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| Inexpensive Capillary Discharge X-Ray Laser Driver |
28 MAY 93 |
35 pages |
| Authors:
Alexander M. Panin; MOXTEK INC OREM UT
|
| In Phase I of the research we computationally modelled a capillary discharge device capable of producing the necessary plasma conditions to demonstrate ASE in argon at a wavelength of about 700 angstroms. Phase 11 of the research will involve the development and diagnosis of the experimental apparatus necessary to demonstrate ASE in argon. The scaling and modification of that apparatus to demonstrate ASE at shorter wavelengths using higher-Z materials will ... |
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| Kwalificate/Classificatie van Explosieve Stoffen en Munitie. Rapport 2. Testontwikkeling (Qualification/Classification Explosive Materials and Munition. 2. Test Development |
NOV 92 |
|
| Authors:
M. W. Dirkse; R. Eerligh; E. G. De Jong; H. P. De Klerck; H. H. Kodde; PRINS MAURITS LABORATORIUM TNO RIJSWIJK (NETHERLANDS)
|
| In order to supply the armed forces with adequate support in the filed of qualification of explosive substances and munition, the TNO-PML performed a research assignment in which a number of preliminary activities were executed in the field mentioned above. The activities were carried out in the period June 1991-June 1992. First an overview is made of the relevant STANAG's and AOP's. Furthermore, it was checked which of the tests ... |
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| The Effect of Yaw Cards on the Pitching and Yawing Motion of Symmetric Projectiles |
MAY 92 |
46 pages |
| Authors:
Robert L. McCoy; ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| This report presents an improved method for analysis of the effect of yaw cards on the determination of the pitching moment coefficient of symmetric missiles. Several comparisons of the present method axe made with spark photography range results obtained for the same projectiles, and a proper treatment of yaw-card data is shown to significantly improve the agreement between the two techniques. Yaw Cards, Card Normal Force, Pitch(motion), Pitching Motion, Card ... |
|
| Microwave Interactions with Plasmas |
APR 92 |
69 pages |
| Authors:
D. J. Eckstrom; R. J. Vidmar; K. R. Stalder; SRI INTERNATIONAL MENLO PARK CA
|
| Microwave interactions with a cold, collisional plasma having gradual density gradients were studied. The plasma was created by the photoionization of tetrakisdimethylaminoethylene (TMAE) vapor seeded into atmospheric pressure helium. Photoionization was provided primarily by sparkboard Spatial scans of the absorption of a microwave probe beam along chords across the plasma, with subsequent Abel inversion, yielded three-dimensional plasma density profiles that showed a gradual decrease in the peak plasma density versus ... |
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| Formal Verification of Digital Logic |
DEC 91 |
211 pages |
| Authors:
Stuart L. Labovitz; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
|
| The most widely used technique for checking the correctness of digital circuits designs is simulation. As the complexity of digital circuits has continued to grow, however, circuit designers have become unable to perform complete simulations of their integrated circuits. Formal hardware verification provides an alternative approach, performing a series of mathematical proofs in order to show that the construction of the circuit from its submodules will result in the intended ... |
|
| A Quasi-Equilibrium Kinetic Model of HF Air Breakdown |
SEP 91 |
81 pages |
| Authors:
A. E. Rodriguez; M. G. White; TETRA CORP ALBUQUERQUE NM
|
| In Phase I of the program, we developed the basic tools needed to build a high-frequency air breakdown model. We developed a Quasi-Equilibrium Methodology (QEM) for extending fluid electron transport models to the nonequilibrium regime, based on assuming that the transport coefficients relax toward their equilibrium values on time scales quantified by time-dependent Boltzmann equation solutions. Our analysis of nonequilibrium electron transport discovered and explained a velocity overshoot effect that ... |
|
| The Effects of Blast Trauma (Impulse Noise) on Hearing: A Parametric Study |
MAY 91 |
127 pages |
| Authors:
Roger P. Hamernik; William A. Ahroon; George Turrentine; Robert I. Davis; Keng D. Hsueh; STATE UNIV OF NEW YORK COLL AT PLATTSBURGH AUDITORY RESEARCH LAB
|
| The primary goal of this research project was to produce a data base from which one could estimate the hazards to hearing associated with a wide variety of non-reverberant (free-field) blast were exposures. To achieve this objective four different blast wave generation devices were designed. Three of these sources are based upon shock tube methods and one uses a high energy electrical discharge to produce a shock wave. The four ... |
|
| The Effects of Blast Trauma (Impulse Noise) on Hearing: A Parametric Study Source IV |
MAY 91 |
42 pages |
| Authors:
Roger P. Hamernik; William A. Ahroon; George A. Turrentine; Robert I. Davis; Keng D. Hsueh; STATE UNIV OF NEW YORK COLL AT PLATTSBURGH AUDITORY RESEARCH LAB
|
| The first and primary goal of this contract is to study the effects of high level blast wave exposure on the conductive and sensory structures of the mammalian ear. This includes the use of the auditory evoked potential to measure hearing thresholds and tuning curves prior to and after exposure to various blast waves. Parameters of the blast waves studied include intensity, spectral composition, number of impulses and repetition rate. ... |
|
| Aerodynamic Coefficients of the M483A1 Determined from Spark Range Tests |
APR 91 |
43 pages |
| Authors:
Robert H. Whyte; ARROW TECH ASSOCIATES SOUTH BURLINGTON VT
|
| The aerodynamic coefficients of the M483A1 have been refined based on analysis of 65 BRL Transonic Range tests. Both the original M483A1 tests (1975) and the latest tests from 1987-1989 were analyzed utilizing a six degree-of- freedom technique during September-October 1990. The Magnus moment was found to be extremely nonlinear with angle of attack and Mach number. The size of the slow arm limit cycle was computed along the region ... |
|
| Review of ASTM Symposium on Surface Crack Growth: Models, Experiments, and Structures |
NOV 90 |
21 pages |
| Authors:
W. G. Reuter; J. H. Underwood; J. C. Newman; ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER WATERVLIET NY BENET LABS
|
| An overview of the ASTM Symposium on Surface Cracks: Models, Experiments, and Structures, held on 25 April 1988 in Sparks, Nevada, is presented. The background and objective for the symposium are described and the technical papers presented and published in the proceedings are summarized. The papers are in two general categories: (a) results of analytical models and experiments of surface-cracked specimens and components subjected to monotonic loading, and (b) experiments ... |
|
| CRC Program for Quantifying Performance of Knock-Sensor-Equipped Vehicles with Varying Octane Level |
AUG 90 |
46 pages |
| Authors:
COORDINATING RESEARCH COUNCIL INC ATLANTA GA
|
| A pilot study was conducted under the auspices of the Coordinating Research Council, Inc. (CRC) to assess the potential effects of gasoline octane quality on acceleration performance, fuel economy and driveability in vehicles equipped with electronic spark control systems (knock sensors). Fourteen vehicles were tested by five participating laboratories on CRC unleaded reference fuels of varying octane quality (78 to 104 RON). The test vehicles included nine naturally-aspirated and five ... |
|
| Evaluation of PVDF Piezopolymer for Use as a Shock Gauge |
JUN 90 |
16 pages |
| Authors:
Piyush K. Dutta; John Kalafut; COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH
|
| About a century ago, piezoelectric solids such as quartz and ceramics were discovered. They have been since used as phonograph pickups, transducers and spark igniters for gas stoves, among other things. However, they aren't universally useful. Because of their brittleness, it is difficult to make them into complex shapes, and, because of their high stiffness, they vibrate for a long time, which is undesirable in applications where rapid damping is ... |
|
| JPRS Report, Nuclear Developments |
06 OCT 1989 |
|
| Authors:
JOINT PUBLICATIONS RESEARCH SERVICE ARLINGTON VA
|
| Partial Contents: Nuclear Weapons, Nuclear Development, Nuclear Power Plant, Uranium, Missiles, Space Firm Protested, Satellite, Rocket Launching, Nuclear Submarine, Environmental, Radioactivity, Nuclear Plant, Nuclear Reactor, Radiation Accident, Tritum Sparks. |
|
| Characterization of Chemicals on Engine Exhaust Particles: F101 and F110 Engines |
AUG 89 |
50 pages |
| Authors:
M. R. Kuhlman; J. C. Chuang; BATTELLE MEMORIAL INST COLUMBUS OH
|
| Assessment of the environmental impact of aircraft operations is required by Air force regulations. This program was undertaken to quantify chemicals associated with particulate emissions of two Air Force turbine engines (F101 and F110). The emissions tests were carried out using a test cell at Tinker AFB OK. Emissions were sampled at four power settings for each engine. Measurements were made of particle mass concentration, elemental (inorganic) components, and of ... |
|
| Nonlinear Acoustics: Reflection and Refraction, Propagation in a Periodic Waveguide, Scattering of Sound by Sound, and Ellipsoidal Focusing |
31 JUL 89 |
30 pages |
| Authors:
David T. Blackstock; TEXAS UNIV AT AUSTIN APPLIED RESEARCH LABS
|
| Reflection and refraction of plane finite-amplitude waves at a plane interface between two fluids. The nonlinear equation for three dimensional waves in a thermoviscous, relaxing fluid was derived. A second-order perturbation solution was obtained for the reflection-refraction problem for the case of lossless fluid and an arbitrary source signal. Propagation in periodic waveguide. Propagation has been measured in a plane wave tube loaded periodically with reactive branch elements. Experiments with ... |
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| Nonlinear Acoustics: Reflection and Refraction, Propagation in a Periodic Waveguide, Scattering of Sound by Sound, and Ellipsoidal Focusing |
31 JUL 89 |
28 pages |
| Authors:
David T. Blackstock; TEXAS UNIV AT AUSTIN APPLIED RESEARCH LABS
|
| Reflection and refraction of plane finite-amplitude waves at a plane interface between two fluids. The nonlinear equation for three-dimensional waves in a thermoviscous, relaxing fluid was derived. A second-order perturbation solution was obtained for the reflection-refraction problem for the case of a lossless fluid and an arbitrary source signal. Propagation in a periodic waveguide. Propagation has been measured in a plane wave tube loaded periodically with reactive branch elements. Experiments ... |
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| Combustion by Pulsed Jet Plumes - Key to Controlled Combustion Engines |
03 MAR 89 |
|
| Authors:
A. K. Oppenheim; J. Beltramo; D. W. Faris; J. A. Maxson; K. Hom; CALIFORNIA UNIV BERKELEY
|
| Pulsed Jet Combustion (PJC) is introduced here as a key element for engines where the progress of combustion is interactively controlled by a microprocessor system. Practical realization of PJC presented here involves the use of an 18 mm plug containing a cavity, where a rich mixture is ignited by a conventional spark discharge, closed by a tip with a suitable orifice to form the effluent stream. Its performance is determined ... |
|
| Aeroballistic Research Facility Data Analysis System (ARFDAS) |
SEP 88 |
144 pages |
| Authors:
Mark Fischer; Wayne Hathaway; GENERAL ELECTRIC CO BURLINGTON VT ARMAMENT SYSTEMS DEPT
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| This report documents the computerized analysis programs used to examine free-flight, ballistic trajectory data (spatial position, angular orientation, and time) obtained at the United States Air Force Aeroballistic Research Facility (ARF). The Aeroballistic Research Facility Data Analysis System (ARFDAS) is a set of Fortran programs used to extract aerodynamic coefficients from experimental spark range data. This report, essentially a User's Manual, concentrates on how to utilize ARFDAS to conduct the ... |
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| Airborne Interception Radar; the Techniques Now Bubbling Under. |
JUL 1988 |
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| Authors:
D. Boyle
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| An Advanced Flight Control and Navigation System Implementation for Tactical Helicopters. |
JUL 1988 |
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| Authors:
C. T. Bye; J. T. Bakken; HONEYWELL INC MINNEAPOLIS MN
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| Unprecedented demands will be placed on the flight control and navigation equipment of the next-generation of Army helicopters to enable single crewmember operability in tactical environments. These demands require a degree of automation, and assurance of a level of pilot confidence not yet achieved on conventional, present-generation vehicles. The challenge of providing the requisite levels of navigation and flight control redundancy leads the system designer to consider a tightly integrated ... |
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