3,500
3.5K
May 23, 2011
05/11
by
Herring, Mack R
texts
eye 3,500
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A history of the NASA John C. Stennis Space Center is presented. A study of the Apollo era is provided. This new addition to the NASA history series is also an allegory of the Center's relationship to the local communities in Mississippi and Louisiana, its sister Centers, and to NASA Headquarters.
Topics: SUPERCONDUCTORS (MATERIALS), MIXERS, MICROWAVE FREQUENCIES, FREQUENCY RANGES, BROADBAND, ASTRONOMY,...
1,283
1.3K
Aug 1, 2010
08/10
by
Taranik, James V.; Hsu, Liang C.; Spatz, David M.; Chenevey, Michael J
texts
eye 1,283
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The following subject areas are covered: (1) genetic, spectral, and LANDSAT Thematic Mapper imagery relationship between desert varnish and tertiary volcanic host rocks, southern Nevada; (2) reconnaissance geologic mapping of the Kane Springs Wash Volcanic Center, Lincoln County, Nevada, using multispectral thermal infrared imagery; (3) interregional comparisons of desert varnish; and (4) airborne scanner (GERIS) imagery of the Kane Springs Wash Volcanic Center, Lincoln County, Nevada.
Topics: ACOUSTICS, FREQUENCY RANGES, TIME, BOUNDARY CONDITIONS, DUCTS, REFLECTANCE, SOUND WAVES, WALLS,...
1,213
1.2K
May 23, 2011
05/11
by
Purba, Josua Bisuk Mubyarto; Horan, Sheli
texts
eye 1,213
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This research investigates the effect of pulse shaping QPSK on bandwidth efficiency over a non-linear channel. This investigation will include software simulations and the hardware implementation. Three kinds of filters: the 5th order Butterworth filter, the 3rd order Bessel filter and the Square Root Raised Cosine filter with a roll off factor (alpha) of 0.25,0.5 and 1, have been investigated as pulse shaping filters. Two different high power amplifiers, one a Traveling Wave Tube Amplifier...
Topics: COSMOLOGY, MICROWAVES, ANISOTROPY, BACKGROUND RADIATION, RADIOMETERS, SKY SURVEYS (ASTRONOMY),...
1,084
1.1K
Jul 12, 2010
07/10
by
NON
texts
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The variations in data received from rocket-borne and balloon-borne instruments are discussed. Indirect techniques to measure and monitor the solar constant are presented. Emphasis is placed on the correlation of data from the Solar Maximum Mission and the Nimbus 7 satellites.
Topics: DEEP SPACE NETWORK, SPECTRUM ANALYSIS, RADIO ANTENNAS, RADIO ASTRONOMY, ASTRONOMICAL OBSERVATORIES,...
989
989
Jul 11, 2010
07/10
by
Gluzek, F.; Mokadam, R. G.; To, I. H.; Stanitz, J. D.; Wollschlager, J
texts
eye 989
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A rotating, positive displacement vane pump with an integral boost stage was designed to pump saturated liquid oxygen and liquid hydrogen for auxiliary propulsion system of orbit transfer vehicle. This unit is designed to ingest 10% vapor by volume, contamination free liquid oxygen and liquid hydrogen. The final pump configuration and the predicted performance are included.
Topics: AEROELASTICITY, TRANSFER FUNCTIONS, WIND TUNNEL MODELS, CONTROL THEORY, FLUTTER, OPTIMAL CONTROL,...
This volume of reports is the 2013 Annual Report of the International VLBI Service for Geodesy and Astrometry (IVS). The individual reports were contributed by VLBI groups in the international geodetic and astrometric community who constitute the permanent components of IVS. The IVS 2013 Annual Report documents the work of the IVS components for the calendar year 2013, our fifteenth year of existence. The reports describe changes, activities, and progress of the IVS. Many thanks to all IVS...
Topics: NASA Technical Reports Server (NTRS), VERY LONG BASE INTERFEROMETRY, ASTROMETRY, GEODESY,...
654
654
Jul 11, 2010
07/10
by
NON
texts
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THIS COLLECTION PRESENTS EXPERIMENTAL STUDIES OF THE COMBINED EFFECT OF DYNAMIC FACTORS (ACCELERATION AND VIBRATION) AND IONIZING RADIATION ON THE FUNCTIONAL STATE OF THE VESTIBULAR ANALYSOR, HIGHER NERVOUS ACTIVITY AND ANIMAL BEHAVIOR. THE ARTICLE SUMMARIZING THE RESULTS OF THESE AND PREVIOUSLY PUBLISHED WORKS SUBSTANTIATES THE THEORY OF THE IMPORTANCE OF INTRACENTRAL PROCESSES IN THE REACTIONS OF THE CENTRAL NERVOUS SYSTEM TO APPLIED COMBINED FORCES. THE COLLECTION ALSO INCLUDES STUDIES OF...
Topics: GROUND STATIONS, SYNCHRONOUS METEOROLOGICAL SATELLITE, AUTOMATIC PICTURE TRANSMISSION, BLOCK...
615
615
Jun 9, 2011
06/11
by
Bradley, Kevin R
texts
eye 615
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This paper describes the development of a methodology for sizing Blended-Wing-Body (BWB) transports and how the capabilities of the Flight Optimization System (FLOPS) have been expanded using that methodology. In this approach, BWB transports are sized based on the number of passengers in each class that must fit inside the centerbody or pressurized vessel. Weight estimation equations for this centerbody structure were developed using Finite Element Analysis (FEA). This paper shows how the...
Topics: PRESSURE SENSORS, LOOP ANTENNAS, FREQUENCY RANGES, RADIO FREQUENCIES, SIGNAL PROCESSING,...
595
595
May 28, 2011
05/11
by
McComas, David J.; Scime, Earl; Skoug, Rut; Blake, Bernard; Burch, James; Fahr, Hans; Funsten, Herbert; Gruntman, Mike; Mitchell, Don; Pollock, Craig; Roelof, Ed
texts
eye 595
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Two Wide-angle Imaging Neutral-atom Spectrometers (TWINS) is a revolutionary new mission designed to stereoscopically image the magnetosphere in charge exchange neutral atoms for the first time. The authors propose to fly two identical TWINS instruments as a mission of opportunity on two widely- spaced high-altitude, high-inclination US Government spacecraft. Because the spacecraft are funded independently, TWINS can provide a vast quantity of high priority science observations (as identified...
Topics: BOLOMETERS, WAVEGUIDES, HETERODYNING, INFRARED ASTRONOMY, SCANNING ELECTRON MICROSCOPY, FREQUENCY...
540
540
Jul 26, 2010
07/10
by
NON
texts
eye 540
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The 1989 Johnson Space Center (JSC) National Aeronautics and Space Administration (NASA)/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program was conducted by Texas A and M University and JSC. The 10-week program was operated under the auspices of the ASEE. The program at JSC, as well as the programs at other NASA Centers, was funded by the Office of University Affairs, NASA Headquarters, Washington, D.C. The objectives of the program, which began nationally in...
Topics: DYNAMIC CHARACTERISTICS, FREQUENCY RANGES, MAGNETIC FIELDS, MAGNETIC MATERIALS, POWER CONDITIONING,...
Bell System Technical Journal, 10: 4. October 1931 pp 616-627. Audible Frequency Ranges of Music, Speech and Noise. (Snow, W.B.)
Topics: frequency, audible, frequencies, cycles, observers, bass, range, ranges, tests, noises, audible...
506
506
May 23, 2011
05/11
by
Farassat, F.; Myers, M. K
texts
eye 506
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In this paper we discuss two problems of classical duct acoustics: (1) wave propagation in infinite ducts with uniform flow based on a graphical approach, and (2) detection of mode radiation from a duct by an external circular microphone array. In (1) we show that the wave number vectors for a given flow Mach number form an ellipse whose center and shape depend on the Mach number only. We construct graphically the upstream and downstream wave number vectors of modes that propagate in the duct....
Topics: PHASE VELOCITY, BOUNDARY CONDITIONS, ULTRASONIC WAVE TRANSDUCERS, PIEZOELECTRIC TRANSDUCERS,...
502
502
May 29, 2011
05/11
by
Scialdone, John J
texts
eye 502
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An inflatable structural system to deploy a space system such as a solar shield, an antenna or another similar instrument, requires a stiffening element after it is extended by the inflated gas pressure. The stiffening element has to be packaged in a folded configuration before the deployment. It must be relatively small, lightweight, non-damaging to the inflated system, and be able to become stiff in a short time. One stiffening method is to use a flexible material inserted in the deployable...
Topics: DENSITY (MASS/VOLUME), CONTINUOUS WAVE LASERS, DIAMETERS, ELECTROMAGNETIC RADIATION, FIBER OPTICS,...
457
457
May 23, 2011
05/11
by
Suder, Kenneth L
texts
eye 457
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A detailed experimental investigation to understand and quantify the development of loss and blockage in the flow field of a transonic, axial flow compressor rotor has been undertaken. Detailed laser anemometer measurements were acquired upstream, within, and downstream of a transonic, axial compressor rotor operating at design and off-design conditions. The rotor was operated at 100, 85, 80, and 60 of design speed which provided inlet relative Mach numbers at the blade tip of 1.48, 1.26, 1.18,...
Topics: FLIGHT CONDITIONS, ROBUSTNESS (MATHEMATICS), YAW, DEGREES OF FREEDOM, FLY BY WIRE CONTROL,...
455
455
May 6, 2010
05/10
by
Korvin, W.; Steckel, J
texts
eye 455
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Vertical radio frequency test range for antenna radiation measurement
Topics: ANTENNAS, FREQUENCY RANGES, RADIATION MEASUREMENT, RADIO FREQUENCIES, RANGEFINDING, TEST RANGES,...
432
432
May 24, 2011
05/11
by
Johnson, D. A.; Bachalo, W. D.; Owen, F. K
texts
eye 432
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The results of an experimental investigation of shock-induced stall and leading-edge stall on a 64A010 airfoil section are presented. Advanced nonintrusive techniques - laser velocimetry and holographic interferometry - were used in characterizing the inviscid and viscous flow regions. The measurements include Mach contours of the inviscid now regions, and mean velocity, flow direction, and Reynolds shear stress profiles in the separated regions. The experimental observations of this study are...
Topics: MICROGRAVITY, EQUATIONS OF MOTION, CONTROLLERS, FREQUENCY RANGES, ISOLATION, INTERNATIONAL SPACE...
430
430
May 31, 2011
05/11
by
Telban, Robert J.; Cardullo, Frank M.; Houck, Jacob A
texts
eye 430
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This paper discusses the continuation of research into the development of new motion cueing algorithms first reported in 1999. In this earlier work, two viable approaches to motion cueing were identified: the coordinated adaptive washout algorithm or 'adaptive algorithm', and the 'optimal algorithm'. In this study, a novel approach to motion cueing is discussed that would combine features of both algorithms. The new algorithm is formulated as a linear optimal control problem, incorporating...
Topics: MICROPHONES, NOISE REDUCTION, PHASED ARRAYS, CYLINDRICAL BODIES, NOISE MEASUREMENT, AIRCRAFT NOISE,...
424
424
May 26, 2011
05/11
by
Shen, Hao; Tam, Christopher K. W
texts
eye 424
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An imperfectly expanded supersonic jet, invariably, radiates both broadband noise and discrete frequency sound called screech tones. Screech tones are known to be generated by a feedback loop driven by the large scale instability waves of the jet flow. Inside the jet plume is a quasi-periodic shock cell structure. The interaction of the instability waves and the shock cell structure, as the former propagates through the latter, is responsible for the generation of the tones. Presently, there...
Topics: FINITE ELEMENT METHOD, METHOD OF MOMENTS, DIFFERENTIAL EQUATIONS, FREQUENCY RESPONSE, FREQUENCY...
393
393
Jun 1, 2011
06/11
by
Sutkus, Donald J., Jr.; Baughcum, Steven L.; DuBois, Douglas P
texts
eye 393
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This report describes the development of a three-dimensional database of aircraft fuel use and emissions (NO(x), CO, and hydrocarbons) for the commercial aircraft fleet projected to 2020. Global totals of emissions and fuel burn for 2020 are compared to global totals from previous aircraft emission scenario calculations.
Topics: AIRCRAFT NOISE, IMPEDANCE MEASUREMENT, SCALE MODELS, ACOUSTIC PROPERTIES, MINIATURIZATION,...
385
385
Jun 21, 2010
06/10
by
Rossow, V. J
texts
eye 385
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Observations of waterspouts and their parent clouds
Topics: DATA CORRELATION, DIGITAL FILTERS, COMPUTER PROGRAMMING, FOURIER TRANSFORMATION, FREQUENCY RANGES,...
372
372
May 6, 2010
05/10
by
Socki, Richard A.; Niles, Paul B.; Fu, Qi; Gibson, Everett K., Jr
texts
eye 372
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Discoveries of large deposits of sedimentary materials on the planet Mars by landers and orbiters have confirmed the widely held hypothesis that water has played a crucial role in the development of the martian surface. Recent studies have indicated that both water ice and liquid water may have been present and in the case of water ice perhaps is still present on or near the surface of Mars. However, there remains much controversy about the prevailing atmospheric conditions and climate of Mars...
Topics: REVERBERATION CHAMBERS, LOADS (FORCES), STANDARD DEVIATION, ANTENNA DESIGN, SYSTEMS INTEGRATION,...
364
364
May 22, 2011
05/11
by
Gilyard, Glenn; Espana, Marti
texts
eye 364
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Increasing competition among airline manufacturers and operators has highlighted the issue of aircraft efficiency. Fewer aircraft orders have led to an all-out efficiency improvement effort among the manufacturers to maintain if not increase their share of the shrinking number of aircraft sales. Aircraft efficiency is important in airline profitability and is key if fuel prices increase from their current low. In a continuing effort to improve aircraft efficiency and develop an optimal...
Topics: BENDING, EQUATIONS OF MOTION, FREQUENCY MEASUREMENT, FREQUENCY RANGES, INERTIA, SHEAR STRESS,...
344
344
Jun 1, 2011
06/11
by
Weber; Keh
texts
eye 344
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At the request of the Henschel Aircraft Works. A. G. Berlin. three models of the missile ''Zitterrochen'' were investigated at subsonic velocities.(open jet 215-millimeter diameter) and at supersonic velocities (open jet 110 by 130 millimeters) in order to determine the effect of various wing forms on the air forces and moments. Three-component measurements were taken, and one model was also investigated with deflected control plates.
Topics: EXPERIMENT DESIGN, ESTIMATING, FREQUENCY DOMAIN ANALYSIS, AIRCRAFT MODELS, CONTROL EQUIPMENT, REAL...
This volume of reports is the 2012 Annual Report of the International VLBI Service for Geodesy and Astrometry (IVS). The individual reports were contributed by VLBI groups in the international geodetic and astrometric community who constitute the permanent components of IVS. The IVS 2012 Annual Report documents the work of the IVS components for the calendar year 2012, our fourteenth year of existence. The reports describe changes, activities, and progress ofthe IVS. Many thanks to all IVS...
Topics: NASA Technical Reports Server (NTRS), VERY LONG BASE INTERFEROMETRY, ASTROMETRY, GEODESY,...
334
334
May 23, 2011
05/11
by
Coppenbarger, Richard A
texts
eye 334
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Helmet-mounted display (HMD) symbology for an automated Nap-of-the-Earth (NOE) guidance and control system is described. In the automated system, referred to as Pilot-Directed Guidance (PDG), pilot control inputs are interpreted as high-level velocity commands to an inner-loop guidance and control system that is responsible for obstacle detection and avoidance maneuvering. The success of the PDG concept has been shown to be highly dependent upon the intelligent use of inertially stabilized...
Topics: RADOME MATERIALS, TRANSMISSION LOSS, MILLIMETER WAVES, PERMITTIVITY, FREQUENCY RANGES, INCIDENCE,...
329
329
Jun 9, 2011
06/11
by
Mitcheltree, R. A.; Moss, J. N.; Cheatwood, F. M.; Greene, F. A.; Braun, R. D
texts
eye 329
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The selection of the unique aeroshell shape for the Mars Microprobes is discussed. A description of its aerodynamics in hypersonic rarefied, hypersonic continuum, supersonic and transonic flow regimes is then presented. This description is based on Direct Simulation Monte Carlo analyses in the rarefied-flow regime, thermochemical nonequilibrium Computational Fluid Dynamics in the hypersonic regime, existing wind tunnel data in the supersonic and transonic regime, additional computational work...
Topics: COMPUTATION, ELECTRIC FIELDS, DIFFERENTIAL EQUATIONS, APERTURES, CAVITIES, FINITE ELEMENT METHOD,...
328
328
May 29, 2011
05/11
by
Juhasz, Albert J
texts
eye 328
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The purpose of this report was to analyze the heat-transfer problem posed by the determination of spacecraft temperatures and to incorporate the theoretically derived relationships in the computational code TSCALC. The basis for the code was a theoretical analysis of the thermal radiative equilibrium in space, particularly in the Solar System. Beginning with the solar luminosity, the code takes into account these key variables: (1) the spacecraft-to-Sun distance expressed in astronomical units...
Topics: BODY FLUIDS, WATER, DATA ACQUISITION, IMPEDANCE, FREQUENCY RANGES, RESISTORS, ELECTRIC CURRENT,...
327
327
Jun 13, 2011
06/11
by
Matloff, Gregory L.; Johnson, Le
texts
eye 327
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After considering relevant properties of the local interstellar medium and defining a sample interstellar mission, this paper considers possible interstellar applications of the electrodynamic tether, or EDT. These include use of the EDT to provide on-board power and affect trajectory modifications and direct application of the EDT to starship acceleration. It is demonstrated that comparatively modest EDTs can provide substantial quantities of on-board power, if combined with a large-area...
Topics: AURORAS, LONG WAVE RADIATION, EXTRATERRESTRIAL RADIO WAVES, RADIO WAVES, FREQUENCY RANGES, LOW...
306
306
Jun 1, 2011
06/11
by
Hambourger, Paul D
texts
eye 306
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To develop and test new materials for use in space power systems and related space and commercial applications, to assist industry in the application of these materials, and to achieve an adequate understanding of the mechanisms by which the materials perform in their intended applications.
Topics: SUMMER, RAIN, TROPICAL REGIONS, AFRICA, TRMM SATELLITE, ANNUAL VARIATIONS, FREQUENCY RANGES
292
292
Jun 12, 2011
06/11
by
Jones, Thomas W.; Lunsford, Charles B
texts
eye 292
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A series of wind tunnel tests have been conducted to evaluate a multi-camera videogrammetric system designed to measure model attitude in hypersonic facilities. The technique utilizes processed video data and applies photogrammetric principles for point tracking to compute model position including pitch, roll and yaw variables. A discussion of the constraints encountered during the design, development, and testing process, including lighting, vibration, operational range and optical access is...
Topics: VELOCITY DISTRIBUTION, ACOUSTIC EMISSION, ACOUSTIC EXCITATION, ALUMINUM, DISTANCE, EXCITATION,...
261
261
May 30, 2011
05/11
by
Albertson, Cindy W.; Emami, Saie
texts
eye 261
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Results of a series of shakedown tests to eliminate facility/engine interactions in an open-jet scramjet test facility are presented. The tests were conducted with the NASA DFX (Dual-Fuel eXperimental scramjet) engine in the NASA Langley Combustion Heated Scramjet Test Facility (CHSTF) in support of the Hyper-X program, The majority of the tests were conducted at a total enthalpy and pressure corresponding to Mach 5 flight at a dynamic pressure of 734 psf. The DFX is the largest engine ever...
Topics: ACOUSTIC MEASUREMENT, AEROACOUSTICS, SHEAR LAYERS, UNSTEADY FLOW, COMPUTERIZED SIMULATION,...
260
260
May 23, 2011
05/11
by
Jolliff, B. L.; Haskin, L. A
texts
eye 260
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The impact that produced North Ray Crater, Apollo 16 landing site, exhumed rocks that include relatively mafic members of the lunar ferroan anorthositic suite. Bulk and mineral compositions indicate that a majority of 2-4 mm lithic fragments from sample 67513, including impact breccias and monomict igneous rocks, are related to a common noritic-anorthosite precursor. Compositions and geochemical trends of these lithic fragments and of related samples collected along the rim of North Ray Crater...
Topics: AIRCRAFT CONTROL, FLIGHT TESTS, FLIGHT CHARACTERISTICS, AIRCRAFT PILOTS, PILOT INDUCED OSCILLATION,...
250
250
May 27, 2011
05/11
by
Thompson, Wilbur E.; Horne, Walter B
texts
eye 250
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The low-speed (up to 4 miles per hour) yawed-rolling characteristics of two 56 x 16 32-ply-rating, type 7 aircraft tires under straight-yawed rolling were determined over a range of inflation pressures and yaw angles for a vertical load approximately equal to 75 percent of the rated vertical load. The quantities measured or determined included cornering force, drag force self-alining torque, pneumatic caster vertical tire deflection, yaw angle, and relaxation length. During straight-yawed...
Topics: CONTROL THEORY, EQUATIONS OF MOTION, AIRCRAFT STABILITY, BLOCK DIAGRAMS, TRANSFER FUNCTIONS,...
247
247
Jun 12, 2011
06/11
by
Bowen, Brent; Johnson, Paul, et al; Vlasek, Karisa; Russell, Valerie; Teasdale, Jean; Downing, David R.; deSilva, Shan; Higginbotham, Jack; Duke, Edward; Westenkow, Dwayne
texts
eye 247
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This report contains two sections, each of which describes a proposal for a program at the University of Nebraska. The sections are entitled: 1) Aerospace Workforce Development Augmentation Competition; 2) Native Connections: A Multi-Consortium Workforce Development Proposal.
Topics: REAL TIME OPERATION, RUDDERS, TRAJECTORIES, MONTE CARLO METHOD, EXCITATION, FAST FOURIER...
241
241
Jun 9, 2011
06/11
by
Hultgren, Lennart; Ashpis, David E
texts
eye 241
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Modern low-pressure turbines, in general, utilize highly loaded airfoils in an effort to improve efficiency and to lower the number of airfoils needed. Typically, the airfoil boundary layers are turbulent and fully attached at takeoff conditions, whereas a substantial fraction of the boundary layers on the airfoils may be transitional at cruise conditions due to the change of density with altitude. The strong adverse pressure gradients on the suction side of these airfoils can lead to...
Topics: BOUNDARY LAYER STABILITY, SURFACE TEMPERATURE, TEMPERATURE MEASUREMENT, TRANSITION FLOW, HYPERSONIC...
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240
May 22, 2011
05/11
by
NON
texts
eye 240
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A device for measuring turbulence in high-speed flows is provided which includes a micro-sensor thin-film probe. The probe is formed from a single crystal of aluminum oxide having a 14 deg half-wedge shaped portion. The tip of the half-wedge is rounded and has a thin-film sensor attached along the stagnation line. The bottom surface of the half-wedge is tilted upward to relieve shock induced disturbances created by the curved tip of the half-wedge. The sensor is applied using a...
Topics: DENSITY (MASS/VOLUME), FEEDBACK, FIBERS, SIGNAL GENERATORS, TRANSDUCERS, VIBRATION, FREQUENCY...
221
221
Jul 11, 2010
07/10
by
Allen, R. A.; Rose, P. H
texts
eye 221
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No Abstract Available
Topics: RADIO COMMUNICATION, SPACECRAFT COMMUNICATION, SYSTEMS ENGINEERING, DATA LINKS, FREQUENCY RANGES,...
Bell System Technical Journal, 14: 1. January 1935 pp 1-7. Wide Band Transmission Over Balanced Circuits. (Clark, A.B.)
Topics: coaxial, transmission, circuits, balanced, crosstalk, cable, pairs, frequency, cables, attenuation,...
215
215
May 31, 2011
05/11
by
Gill, E.; Naasz, Bo; Ebinuma, T
texts
eye 215
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A closed-loop system for the demonstration of autonomous satellite formation flying technologies using hardware-in-the-loop has been developed. Making use of a GPS signal simulator with a dual radio frequency outlet, the system includes two GPS space receivers as well as a powerful onboard navigation processor dedicated to the GPS-based guidance, navigation, and control of a satellite formation in real-time. The closed-loop system allows realistic simulations of autonomous formation flying...
Topics: AIRCRAFT NOISE, FLIGHT CREWS, SOUND PRESSURE, SHAFTS (MACHINE ELEMENTS), NOISE INTENSITY, FREQUENCY...
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210
Jun 11, 2011
06/11
by
Duda, David P.; Palikonda, Rabindra; Minnis, Patric
texts
eye 210
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Contrail-induced cloud cover has been shown to be a significant factor in regional climate change over the United States of America. As air traffic increases, the potential for globally significant impacts also rises. To better understand and predict these potential climatic effects, it is necessary to develop models that can accurately represent contrail properties based on ambient atmospheric variables including temperature, relative humidity and winds. Several high-resolution numerical...
Topics: ACCIDENT INVESTIGATION, ERRORS, AIRCRAFT ACCIDENTS, HUMAN PERFORMANCE, FREQUENCY RANGES, PILOT ERROR
204
204
May 23, 2011
05/11
by
Cairns, Iver H
texts
eye 204
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Detailed first estimates are presented of angular broadening in the outer heliosphere due to scattering of radio waves by density irregularities. The application is to the 2-3 kHz radiation observed by Voyager. Two plausible turbulence models, which account very well for scattering within 1 AU, are extrapolated beyond 10 AU. Both models predict significant angular broadening in the outer heliosphere, accounting semi- quantitatively alone for the source sizes inferred from roll modulation data....
Topics: GALILEO SPACECRAFT, OCCULTATION, POSITION (LOCATION), NORTHERN HEMISPHERE, FLYBY MISSIONS, RADIO...
198
198
Jun 13, 2011
06/11
by
Haw, Robert J
texts
eye 198
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A proposed Neptune Orbiter Aerocapture mission will use solar electric propulsion to send an orbiter to Neptune. Navigation feasibility of direct-entry aerocapture for orbit insertion at Neptune is shown. The navigation strategy baselines optical imaging and VLBI measurements in order to satisfy the flight system s atmosphere entry flight path angle, which is targeted to enter Neptune with an entry flight path angle of 11.6 degrees. Error bars on the entry flight path angle of plus or minus...
Topics: CARBON NANOTUBES, PURIFICATION, FREQUENCY RANGES, DISSOCIATION, WATER, HYDROGEN PEROXIDE
198
198
Jun 20, 2010
06/10
by
Kumagai, N.; Kurazono, S.; Sueta, T
texts
eye 198
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Quasi-optic directional coupler, attenuator, for beam waveguide in region of millimeter and submillimeter waves
Topics: ATTENUATORS, SUBMILLIMETER WAVES, COUPLERS, MILLIMETER WAVES, WAVEGUIDES, BANDWIDTH, FREQUENCY...
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186
Jun 12, 2011
06/11
by
Blair, M. W.; Kalchgruber, R.; Deo, S.; McKeever, S. W. S
texts
eye 186
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The surface of Mars has been subject to aeolian, fluvial, and periglacial activity in the (relatively) recent past. Unfortunately, chronological dating of recent events on Mars is difficult as the errors associated with crater counting are comparable to younger ages (approx. 1 Ma). Consequently, techniques to quantify the ages of geological processes on Mars have become an important area of research. Optically stimulated luminescence (OSL) dating is one candidate technique for in-situ dating of...
Topics: MINERALS, MARS SURFACE, HEMATITE, CURIE TEMPERATURE, FERROMAGNETIC MATERIALS, TITANIUM, CRYSTALS,...
182
182
Jun 9, 2011
06/11
by
Duquesne, N.; Carlson, J. R.; Rumsey, C. L.; Gatski, T. B
texts
eye 182
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Transport aircraft performance is strongly influenced by the effectiveness of high-lift systems. Developing wakes generated by the airfoil elements are subjected to strong pressure gradients and can thicken very rapidly, limiting maximum lift. This paper focuses on the effects of various pressure gradients on developing symmetric wakes and on the ability of a linear eddy viscosity model and a non-linear explicit algebraic stress model to accurately predict their downstream evolution. In order...
Topics: BOUNDARY LAYER SEPARATION, INCOMPRESSIBLE FLOW, PRESSURE OSCILLATIONS, UPSTREAM, VORTICES, WAKES,...
179
179
Jun 13, 2011
06/11
by
Sudbrack, Chantal K.; Noebe, Ronald D.; Seidman, David N
texts
eye 179
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Early-stage phase separation in a Ni-5.2 Al-14.2 Cr at.% superalloy, isothermally decomposing at 873 K, is investigated with atom-probe tomography. Sub-nanometer scale compositional profiles across the gamma/gamma'(L12) interfaces demonstrate that both the gamma-matrix and the gamma'-precipitate compositions evolve with time. Observed chemical gradients of Al depletion and Cr enrichment adjacent to the gamma'-precipitates are transient, consistent with well-established model predictions for...
Topics: MICROGRAVITY, PAYLOADS, INTERNATIONAL SPACE STATION, ACCELERATION MEASUREMENT, VIBRATION,...
Bell System Technical Journal, 9: 3. July 1930 pp 550-566. Effects of Phase Distortion on Telephone Quality. (Steinberg, John C.)
Topics: distortion, phase, frequency, attenuation, delay, wave, filters, articulation, band, speech, system...
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May 23, 2011
05/11
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Rosenbloom, Paul S
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Work on this effort divided up into three phases. The first phase, which spanned the first three years of the effort, focused on 'Research on Soar'. The second phase, which spanned the next 2.5 years of the effort, focused on 'Learning to Use Devices' in the context of Soar. The third phase, which spanned the last two years of the effort, focused on 'Induction as Knowledge Integration'. These three phases will be described in brief in the following three sections.
Topics: ELECTROMAGNETIC RADIATION, ELECTRON BEAMS, ACOUSTIC INSTABILITY, MAGNETOHYDRODYNAMIC STABILITY,...
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May 23, 2011
05/11
by
Rosenbloom, Paul S
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Work on this effort divided up into three phases. The first phase, which spanned the fust three years of the effort, focused on 'Research on Soar'. The second phase, which spanned the next 2.5 years of the effort, focused on 'Learning to Use Devices' in the context of Soar. The third phase, which spanned the last two years of the effort, focused on 'Induction as Knowledge Integration'.
Topics: PLASMA WAVES, BROADBAND, PLASMASPHERE, LOOP ANTENNAS, DIPOLE ANTENNAS, POLAR REGIONS, PLASMA...
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May 29, 2011
05/11
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Lindstrom, Marily
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This newsletter contains something for everyone It lists classifications of about 440 meteorites mostly from the 1997 and 1998 ANSMET (Antarctic Search for Meteorites) seasons. It also gives descriptions of about 45 meteorites of special petrologic type. These include 1 iron, 17 chondrites (7 CC, 1 EC, 9 OC) and 27 achondrites (25 HED, UR). Most notable are an acapoloite (GRA98028) and an olivine diogenite (GRA98108).
Topics: TUNABLE LASERS, NITROGEN, STOKES LAW OF RADIATION, ENERGY CONVERSION, ARGON, FLUORIDES, FORCED...
