the temporal variation of intense rainfalls is of great importance in hydrological analyses and prediction, which is required for dimensioning engineering projects. Therefore, this study has as objective to determine the temporal distribution of intense rainfalls with durations of 1, 2 and 4 h in Campinas, state of Sao Paulo, Brazil, for the period from 1997 to 2016. The rainfalls with duration of 1 h were subdivided in three intervals of 20 min. Rainfalls with duration of 2 and 4 h were...
Topics: heavy rainfalls, hyetograph, probability distribution, temporal distribution.
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398
May 22, 2011
05/11
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Workman, Gary L.; Smith, Guy A.; Kosten, Susa
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Improved transmission properties for fluoride fibers due to space processing has great potential for commercial benefits. Phase A design study will determine conceptual feasibility and provide initial definition of the technical requirements and design issues for space.
( 1 reviews )
Topics: ARTIFICIAL INTELLIGENCE, FEASIBILITY, PLANNING, PROBLEM SOLVING, ALGORITHMS, TEMPORAL DISTRIBUTION
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87
Jun 2, 2011
06/11
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Keller, Richar
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Managing the information generated during the course of a scientific investigation is both a challenging and an essential task for NASA scientists. During an investigation, experimental records must be kept up-to-date and made accessible to all members of a scientific team. After an investigation, a thorough set of records is essential for historical documentation, reproducibility, and overall scientific credibility . These information-management requirements are particularly challenging when...
Topics: AEROSOLS, ATMOSPHERIC COMPOSITION, OZONE, SPATIAL DISTRIBUTION, TEMPORAL DISTRIBUTION, MORPHOLOGY
Lake Léré is situated in the Mayo-Kebbi locality southwest of Chad, it is the site for RAMSAR since 2001 hosting manatee (Trichechus senegalensis). This lake has been under study with the aimed of determining the structure of zooplankton community from February 2016 to April 2017. For this study, three sampling stations were chosen and divided into 2 to 3 layers from water surface towards the bottom. A total of 49 zooplanktonic species were identifiedin LakeLéré. This was dominated by...
Topics: zooplankton, specific diversity, spatio-temporal distribution of Lac Léré, Chad.
Mendeley Climate Change Library
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Jul 6, 2019
07/19
by
Chun Lai Zhang; Qing Li; Ya Ping Shen; Na Zhou; Xue Song Wang; Jiao Li; Wen Ru Jia
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Aeolian desertification, one of the most serious environmental issues, has hampered socioeconomic development on the Qinghai-Tibet Plateau (QTP). However, research on aeolian desertification in this region has been limited. To develop a set of science-based preventive measures to mitigate desertification in this region, it is first necessary to clarify the status, evolution, and driving factors of aeolian desertification. In this study, based on extensive field investigations and a current...
Topics: Aeolian desertification, Driving force, Landsat images, Qinghai-Tibet Plateau, Spatial-temporal...
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Jul 12, 2010
07/10
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Bruckner, A. P.; Mattick, A. T
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A high-effectiveness liquid droplet/gas heat exchanger (LDHX) concept for thermal management in space is described. Heat is transferred by direct contact between fine droplets (approx. 100 to 300 micron diameter) of a suitable low vapor pressure liquid and an inert working gas. Complete separation of the droplet and gas media in the zero-g environment is accomplished by configuring the LDHX as a vortex chamber. The large heat transfer area presented by the small droplets permits heat exchanger...
Topics: GAMMA RAY BURSTS, SPECTRAL SIGNATURES, TEMPORAL DISTRIBUTION, DATA REDUCTION, MONTE CARLO METHOD,...
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May 23, 2011
05/11
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Schmidt, Jurgen G.; Orgel, Leslie E.; Nielsen, Peter E
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Ion-exchange chromatography is a well-established method for the analysis and purification of phosphodiester-linked oligonucleotides. If elution is carried out under alkaline conditions, the secondary structure of G- and C-rich oligomers is disrupted. Furthermore, elution times become more sensitive to the G and T content of the oligomer, because G and T are deprotonated at pH 10. In recent work on peptide-nucleic acids (PNAs) we noted that mixtures of PNA oligomers G(sub 4), G(sub 6), G(sub...
Topics: GAMMA RAY BURSTS, RESEARCH, HISTORIES, TEMPORAL DISTRIBUTION, TIME DEPENDENCE, SPATIAL...
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300
May 31, 2011
05/11
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Kohlstedt, David L
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Two important goals of our experimental investigation of the rheological behavior of diabase rocks were: (1) to determine flow laws describing their creep behavior over wide ranges of temperature, stress and strain rate and (2) to develop an understanding of the physical mechanisms by which these rocks flow under laboratory conditions. With this basis, a primary objective then was to construct constitutive equations that can be used to extrapolate from laboratory to planetary conditions. We...
Topics: ULTRAVIOLET SPECTROMETERS, JUPITER (PLANET), HYDROCARBONS, AEROSOLS, MIXING RATIOS, JUPITER...
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Jun 12, 2011
06/11
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Holt, J. W.; Blankenship, D. D.; Morse, D. L.; Peters, M. E.; Kempf, S. D
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We have collected roughly 1,000 line-km of airborne radar sounding data over glaciers, rock/ice glaciers, permafrost, subsurface ice bodies, ice-covered saline lakes, and glacial deposits in Taylor and Beacon Valley. These data are being analyzed in order to develop techniques for discriminating between subsurface and off-nadir echoes and for detecting and characterizing subsurface interfaces. The identification of features on Mars exhibiting morphologies consistent with ice/rock mixtures,...
Topics: TRMM SATELLITE, ATMOSPHERIC HEATING, LATENT HEAT, ATMOSPHERIC MODELS, RAIN, SATELLITE OBSERVATION,...
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Jun 11, 2011
06/11
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Figer, Donald F.; Rauscher, Bernie J.; Regan, Michael W.; Morse, Ernie; Balleza, Jesus; Bergeron, Louis; Stockman, H. S
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The Independent Detector Testing Laboratory (IDTL) is jointly operated by the Space Telescope Science Institute (STScI) and the Johns Hopkins University (JHU), and is assisting the James Webb Space Telescope (JWST) mission in choosing and operating the best near-infrared detectors. The JWST is the centerpiece of the NASA Office of Space Science theme, the Astronomical Search for Origins, and the highest priority astronomy project for the next decade, according to the National Academy of...
Topics: CARBON DIOXIDE CONCENTRATION, SEA WATER, OCEAN SURFACE, GEOGRAPHIC DISTRIBUTION, TEMPORAL...
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461
Jun 11, 2011
06/11
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Jeram, Geoffrey J
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eye 461
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This Open Platform for Limit Protection guides the open design of maneuver limit protection systems in general, and manned, rotorcraft, aerospace applications in particular. The platform uses three stages of limit protection modules: limit cue creation, limit cue arbitration, and control system interface. A common set of limit cue modules provides commands that can include constraints, alerts, transfer functions, and friction. An arbitration module selects the ''best'' limit protection cues and...
Topics: BIOMASS BURNING, ARID LANDS, GRASSLANDS, AFRICA, SATELLITE IMAGERY, ANNUAL VARIATIONS, NIGHT,...
The South Atlantic Convergence Zone (SACZ) is the main meteorological system responsible for the occurrence of regular rains in almost the entire central and southeastern region of Brazil in rainy season. During the January 2020 these complex system has generate severe storms especially in Minas Gerais state. These intense episodes of precipitation induced real catastrophes and numerous impacts throughout Metropolitan Region of Belo Horizonte (MRBH) like overflow of water courses and...
Topics: Intense rains, Temporal distribution of rainfall, Spatial distribution of rainfall, Synthetic...
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528
May 30, 2011
05/11
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Litchford, R. J
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eye 528
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The prospects for realizing an integrated pulse detonation propulsion and magnetohydrodynamic (MHD) power system are examined. First, energy requirements for direct detonation initiation of various fuel-oxygen and fuel-air mixtures are deduced from available experimental data and theoretical models. Second, the pumping power requirements for effective chamber scavenging are examined through the introduction of a scavenging ratio parameter and a scavenging efficiency parameter. A series of...
Topics: HYDROLOGY MODELS, TEMPORAL DISTRIBUTION, SPATIAL DISTRIBUTION, METHANE, EMISSION, GREENHOUSE...
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May 23, 2011
05/11
by
BhanuSankaraRao, K.; Schuster, H.; Halford, G. R
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The damage mechanisms influencing the axial strain-controlled Low-Cycle Fatigue (LCF) behavior of alloy 800H at 850 C have been evaluated under conditions of equal tension/compression ramp rates (Fast-Fast (F-F): 4 X 10(sup -3)/s and Slow-Slow (S-S): 4 X 10(sup -5)/s) and asymmetrical ramp rates (Fast-Slow (F-S): 4 x 10(sup -3)/s / 4 X 10(sup -5/s and Slow-Fast (S-F): 4 X 10(sup -5) / 4 X 10(sup -3)/s) in tension and compression. The fatigue life, cyclic stress response, and fracture modes were...
Topics: RING CURRENTS, ELECTRIC FIELDS, STORMS, MAGNETOSPHERES, MAGNETIC STORMS, TEMPORAL DISTRIBUTION,...
The principal scientific aim of this project is to better understand the observed long-term temporal variations in the Sun's luminosity. Satellite observations have revealed that the flux of solar radiation striking the Earth is modulated by the solar magnetic cycle, being approximately 0.1 percent larger during solar maximum. The impact of this irradiance modulation on terrestrial climate is difficult to model. However, the correlation between the Maunder minimum (a period of low solar...
Topics: NASA Technical Reports Server (NTRS), PHOTOMETRY, SOLAR ACTIVITY EFFECTS, TEMPORAL DISTRIBUTION,...
A method of observing the interdiffusion of a pair of miscible liquids is based on the use of a common-path interferometer (CPI) to measure the spatially varying gradient of the index refraction in the interfacial region in which the interdiffusion takes place. Assuming that the indices of refraction of the two liquids are different and that the gradient of the index of refraction of the liquid is proportional to the gradient in the relative concentrations of either liquid, the diffusivity of...
Topics: NASA Technical Reports Server (NTRS), DIFFUSION, INTERFEROMETRY, LIQUIDS, SPATIAL DISTRIBUTION,...
An interval-based temporal reasoning algorithm is applied to planning problems. The generation of all feasible temporal plans and its importance are discussed.
Topics: NASA Technical Reports Server (NTRS), ARTIFICIAL INTELLIGENCE, FEASIBILITY, PLANNING, PROBLEM...
This is a final report for research supported by the National Aeronautics and Space Administration issued through the Office of Space Science Planetary Geology and Geophysics Program, covering all relevant activities during its 3-year period of funding from 02/01/2002 through to 01/31/2005. The ongoing aim of the research supported through this grant, and now through a successor award, is to investigate the origin of interplanetary dust particles (IDPs) and their dynamical and collisional...
Topics: NASA Technical Reports Server (NTRS), INTERPLANETARY DUST, PLANETARY GEOLOGY, PARTICLES, NASA...
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189
Jul 26, 2010
07/10
by
Stevenson, Charles G.; Katnik, Gregory N.; Higginbotham, Scott A
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A Debris/Ice/TPS assessment and photographic analysis was conducted for Space Shuttle Mission STS-28R. Debris inspections of the flight elements and launch pad are performed before and after launch. Ice/Frost conditions on the External Tank are assessed by the use of computer programs, nomographs, and infrared scanner data during cryogenic loading of the nomographs, and infrared scanner data during cryogenic loading of the vehicle followed by on-pad visual inspection. High speed photography is...
Topics: SOLAR ACTIVITY, SOLAR MAXIMUM MISSION, SOLAR PROMINENCES, SOLAR RADIATION, SOLAR ROTATION, TIME...
This grant is an extension of Grant NAG5-8929 (Drexel Project Number 230026), resulting from extensions necessary to meet changing science objectives as described in the final report for NAG5-8929, a copy of which is attached. The instrument configuration resulting from NAG54929 has remained basically intact. Cosine response measurements conducted by James Slusser s group at Fort Collins, Colorado, in support of the proposal for Aura ground validation mentioned in the final report for...
Topics: NASA Technical Reports Server (NTRS), FLUID FLOW, ULTRAVIOLET DETECTORS, DATA ACQUISITION, TEMPORAL...
The effect of initial mean velocity field on the stability characteristics of longitudinal vortices is documented in detail. The temporal stability of isolated multiple cell vortices is considered. The types of vortices studied include single cell as well as two and three cell vortices. It is shown that cell multiplicity in the vortex core has drastic effects on the stability characteristics. On the basis of numerical calculations, it is concluded that the growth rates of instabilities in...
Topics: NASA Technical Reports Server (NTRS), FLOW STABILITY, TEMPORAL DISTRIBUTION, VORTICES, FLOW...
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260
May 29, 2011
05/11
by
Walton, Joan D.; Filman, Robert E.; Korsmeyer, David J
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DARWIN is a web-based system for presenting the results of wind-tunnel testing and computational model analyses to aerospace designers. DARWIN captures the data, maintains the information, and manages derived knowledge (e.g. visualizations, etc.) of large quantities of aerospace data. In addition, it provides tools and an environment for distributed collaborative engineering. We are currently constructing the third version of the DARWIN software system. DARWN's development history has, in some...
Topics: GREENLAND, PASSIVE SATELLITES, CROSS POLARIZATION, GRADIENTS, ICE, MELTING, ANNUAL VARIATIONS,...
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200
May 23, 2011
05/11
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Collison, Alan J.; Watson, William D
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In previous calculations for the luminosities of 22 GHz water masers, the pumping is reduced and ultimately quenched with increasing depth into the gas because of trapping of the infrared (approximately equals 30-150 micrometers), spectral line radiation of the water molecule. When the absorption (and reemission) of infrared radiation by dust grains is included, we demonstrate that the pumping is no longer quenched but remains constant with increasing optical depth. A temperature difference...
Topics: PULSARS, PHOTONS, TORQUE, X RAYS, GAMMA RAY BURSTS, ENERGY SPECTRA, GAMMA RAY OBSERVATORY, TEMPORAL...
The sound radiated by isotropic turbulence is computed using inertial range scaling expressions for the relevant two time and two point correlations. The result depends on whether the decay of Eulerian time correlations is dominated by large scale sweeping or by local straining: the straining hypothesis leads to an expression for total acoustic power, whereas the sweeping hypothesis leads to a more recent result.
Topics: NASA Technical Reports Server (NTRS), HIGH REYNOLDS NUMBER, ISOTROPIC TURBULENCE, SOUND GENERATORS,...
An initial application of multispectral LIDAR data from the NASA airborne oceanographic lidar (AOL) to the mapping of watermass boundaries is presented. The approach uses the multispectral lidar data from the fluorosensing mode in a cluster analysis to define water types. Individual data points are classified as to parent water type(s) and then plotted in plan view to show the watermass boundaries and mixing regions. The methodology was applied to the AOL data from the SUPERFLUX overflights....
Topics: NASA Technical Reports Server (NTRS), IMAGING TECHNIQUES, OPTICAL RADAR, REMOTE SENSING,...
The question of whether the micro scale controls the macro scale or vice-versa remains one of the most challenging problems in plasmas. A particular topic of interest within this context is collisionless magnetic reconnection, where both points of views are espoused by different groups of researchers. This presentation will focus on this topic. We will begin by analyzing the global properties of magnetic reconnection. Following that, we discuss properties of electron diffusion region dynamics...
Topics: NASA Technical Reports Server (NTRS), ELECTRON DIFFUSION, TEMPORAL DISTRIBUTION, SECULAR...
Single Event Effects vulnerability of on-board computers that regulate the: navigational, flight control, communication, and life support systems has become an issue in advanced modern aircraft, especially those that may be equipped with new technology devices in terabit memory banks (low voltage, nanometer feature size, gigabit integration). To address this concern, radiation spectrometers need to fly continually on a multitude of carriers over long periods of time so as to accumulate...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC RADIATION, TEMPORAL DISTRIBUTION, ALTITUDE,...
The question of whether the microscale controls the macroscale or vice-versa remains one of the most challenging problems in plasmas. A particular topic of interest within this context is collisionless magnetic reconnection, where both points of views are espoused by different groups of researchers. This presentation will focus on this topic. We will begin by analyzing the properties of electron diffusion region dynamics both for guide field and anti-parallel reconnection, and how they can be...
Topics: NASA Technical Reports Server (NTRS), ELECTRON DIFFUSION, MAGNETIC FIELD RECONNECTION, MATHEMATICAL...
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265
May 24, 2011
05/11
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Yang, Lee C.; Kuchar, James K
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eye 265
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This paper discusses the development of a prototype alerting system for a conceptual Free Flight environment. The concept assumes that datalink between aircraft is available and that conflicts are primarily resolved on the flight deck. Four alert stages are generated depending on the likelihood of a conflict. If the conflict is not resolved by the flight crews, Air Traffic Control is notified to take over separation authority. The alerting logic is based on probabilistic analysis through...
Topics: SULFUR DIOXIDES, SPATIAL DISTRIBUTION, TEMPORAL DISTRIBUTION, SURFACE PROPERTIES, TORUSES, WINDS...
A history and overview of the observed properties of gamma-ray bursts are presented. The phenomenon of gamma-ray bursts is without precedent in astronomy, having no observed property that would be a direct indicator of their distance and no counterpart object in another wavelength region. Their brief, random appearance only in the gamma-ray region has made their study difficult. The observed time profiles, spectral properties, and durations of gamma-ray bursts cover a wide range. All proposed...
Topics: NASA Technical Reports Server (NTRS), GAMMA RAY BURSTS, RESEARCH, HISTORIES, TEMPORAL DISTRIBUTION,...
Space Technology 5 (ST-5) is a three micro-satellite constellation deployed into a 300 x 4500 km, dawn-dusk, sun-synchronous polar orbit from March 22 to June 21, 2006, for technology validations. In this paper, we present a study of the temporal variability of field-aligned currents using multi-point magnetic field measurements from ST5. The data demonstrate that mesoscale current structures are commonly embedded within large-scale field-aligned current sheets. The meso-scale current...
Topics: NASA Technical Reports Server (NTRS), FIELD ALIGNED CURRENTS, TEMPORAL DISTRIBUTION, SPATIAL...
Central to any analysis of dynamical systems, or large scale motion, is the interpretation of redshifts of galaxies as classical Doppler velocity shifts. This is a testable assumption and for many years evidence has accumulated that is inconsistent with the assumption. Here, the authors review recent evidence suggesting systematic radial dependence and temporal variation of redshifts.
Topics: NASA Technical Reports Server (NTRS), DOPPLER EFFECT, DYNAMICAL SYSTEMS, GALAXIES, RED SHIFT,...
A paper discusses the application of the Hilbert-Huang transform (HHT) method to time-series financial-market data. The method was described, variously without and with the HHT name, in several prior NASA Tech Briefs articles and supporting documents. To recapitulate: The method is especially suitable for analyzing time-series data that represent nonstationary and nonlinear phenomena including physical phenomena and, in the present case, financial-market processes. The method involves the...
Topics: NASA Technical Reports Server (NTRS), HILBERT TRANSFORMATION, TRANSFORMATIONS (MATHEMATICS),...
The question of whether the micro scale controls the macroscale or vice-versa remains one of the most challenging problems in plasmas. A particular topic of interest within this context is collisionless magnetic reconnection, where both points of views are espoused by different groups of researchers. This presentation will focus on this topic. We will begin by analyzing the properties of electron diffusion region dynamics both for guide field and anti-parallel reconnection, and how they can be...
Topics: NASA Technical Reports Server (NTRS), MAGNETIC FIELD RECONNECTION, MATHEMATICAL MODELS, PLASMAS...
The 4th International Conference on Integrating GIS and Environmental Modeling (GIS/EM4) was convened in Banff, Canada, September 2-8, 2000 at The Banff Centre for Conferences. The meeting's purpose, like it's predecessors was to reformulate, each three to four years, the collaborative research agenda for integrating spatio-temporal analysis with environmental simulation modeling.
Topics: NASA Technical Reports Server (NTRS), CONFERENCES, ENVIRONMENT MODELS, GEOGRAPHIC INFORMATION...
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212
May 23, 2011
05/11
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Mathias, Edward C.; Sambamurthi, Jay K.; Alvarado, Alexi
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During the STS-54 launch (RSRM-29), the right hand solid rocket motor experienced a 13.9 psi chamber pressure perturbation at 67 seconds into the motor operation. This pressure augmentation equated to a thrust change of 51 klb. Concerns were raised regarding the adverse effects of this thrust imbalance on the shuttle system and the overall thrust into the external tank structural elements. Pressure perturbations have been observed in solid rocket motors due to expulsion of igniter or insulation...
Topics: SYNTHETIC APERTURE RADAR, ECOSYSTEMS, REMOTE SENSING, BIOCONVERSION, ATMOSPHERIC COMPOSITION,...
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462
May 23, 2011
05/11
by
Berry, Scott A.; Nowak, Robert J
texts
eye 462
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The effects of fin leading edge sweep on peak heating rates due to shock-shock interaction have been experimentally examined in the Langley 20-Inch Mach 6 Tunnel. The shock interaction was produced by the intersection of a planar incident shock (16.8 deg shock angle relative to the freestream, generated by a 9 deg wedge) with the bow shock formed around a O.5-inch diameter cylindrical leading edge fin. Heating distributions along the leading edge stagnation line have been obtained using densely...
Topics: ATMOSPHERIC CHEMISTRY, WATER, PHOTOLYSIS, NITROGEN COMPOUNDS, OXYGEN COMPOUNDS, COMETARY...
The Flare Irradiance Spectral Model (FISM) was first released in 2005 to provide accurate estimates of the solar VUV (0.1-190 nm) irradiance to the Space Weather community. This model was based on TIMED SEE as well as UARS and SORCE SOLSTICE measurements, and was the first model to include a 60 second temporal variation to estimate the variations due to solar flares. Along with flares, FISM also estimates the tradition solar cycle and solar rotational variations over months and decades back to...
Topics: NASA Technical Reports Server (NTRS), SOLAR FLARES, SOLAR CYCLES, IRRADIANCE, SPACE WEATHER,...
The threat of lightning is a daily concern during the warm season in Florida. Research has revealed distinct spatial and temporal distributions of lightning occurrence that are strongly influenced by large-scale atmospheric flow regimes. Previously, the Applied Meteorology Unit (AMU) calculated the gridded lightning climatologies based on seven flow regimes over Florida for 1-, 3- and 6-hr intervals in 5-, 10-,20-, and 30-NM diameter range rings around the Shuttle Landing Facility (SLF) and...
Topics: NASA Technical Reports Server (NTRS), CLIMATOLOGY, LIGHTNING, METEOROLOGY, PROBABILITY THEORY,...
This final report describes the efforts accomplished during the grant's period of performance, covering the period of 1 May 1997 to 30 April 2001, of a NASA Supporting Research and Technology Program grant under the Ionospheric, Thermospheric, and Mesospheric Physics component of the Sun-Earth Connections program. We have met and exceeded the goals set forth in the proposed research objectives. Referred publications have appeared in the scientific literature and several others are in the review...
Topics: NASA Technical Reports Server (NTRS), AURORAS, SPATIAL DISTRIBUTION, DMSP SATELLITES, TEMPORAL...
Historical records and data obtained during the Superflux experiments are used to describe the temporal and spatial variations of the effluent waters of Chesapeake Bay. The alongshore extent of the plume resulting from variations of freshwater discharge into the Bay and the effects of wind are illustrated. Variations of the cross sectional configuration of the plume over portions of a tidal cycle and results of a rapid underway water sampling system are discussed.
Topics: NASA Technical Reports Server (NTRS), CHESAPEAKE BAY (US), ESTUARIES, SPATIAL DISTRIBUTION,...
This is the final report for this project. The purpose of this project was to support PI Wayne Pryor's effort to reduce and analyze Galileo UVS (Ultraviolet Spectrometer) data under the JSDAP program. The spectral observations made by the Galileo UVS were to be analyzed to determine mixing ratios for important hydrocarbon species (and aerosols) in Jupiter's stratosphere as a function of location on Jupiter. Much of this work is still ongoing. To date, we have concentrated on analyzing the...
Topics: NASA Technical Reports Server (NTRS), ULTRAVIOLET SPECTROMETERS, JUPITER (PLANET), HYDROCARBONS,...
Precipitation maxima during the West African summer monsoon propagate generally westward in tandem with African easterly waves. A heretofore unreported, repeating pattern of northward drift of precipitation maxima is detected on Tropical Rainfall Measurement Mission (TRMM satellite) time-latitude distributions of daily accumulations over the eastern tropical Atlantic. Corresponding 3-hourly TRMM accumulations show that the northward drifting envelopes of precipitation during August 2006 are...
Topics: NASA Technical Reports Server (NTRS), CONVECTION, TRMM SATELLITE, THUNDERSTORMS, MESOSCALE...
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264
May 23, 2011
05/11
by
Janes, Daniel M.; Squyres, Steven W
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Coronae on Venus are believed to result from the gravitationally driven relaxation of topography that was originally raised by mantle diapirs. We examine this relaxation using a viscoelastic finite element code, and show that an initially plateau shaped load will evolve to the characteristic corona topography of central raised bowl, annular rim, and surrounding moat. Stresses induced by the relaxation are consistent with the development of concentric extensional fracturing common on the outer...
Topics: PHOTOCHEMICAL REACTIONS, PREDICTIONS, HUBBLE SPACE TELESCOPE, JUPITER (PLANET), SULFUR COMPOUNDS,...
Lidar measurements by UTHE (1972) and similar measurements with acoustic radar by HALL (1972) have shown, that short time variations in the troposphere can be determined. Aerosol backscatter measurements give the vertical structure. A series of such results shows the time variation of the tropospheric structure. The Figure is an example for a measuring period during half an hour in summer 1972 (1 pulse per minute). These variations were produced by humidity variations. For example, at humidity...
Topics: NASA Technical Reports Server (NTRS), TROPOSPHERE, HUMIDITY, AEROSOLS, BACKSCATTERING, OPTICAL...
We have developed and improved helioseismic imaging techniques of the far-side of the Sun as part of a synoptic monitor of solar activity. In collaboration with the MIDI team at Stanford University we are routinely applying our analysis to images within 24 hours of their acquisition by SOHO. For the first time, real-time seismic maps of large active regions on the Sun's far surface are publicly available. The synoptic images show examples of active regions persisting for one or more solar...
Topics: NASA Technical Reports Server (NTRS), SOLAR ACTIVITY, HELIOSEISMOLOGY, ACOUSTIC PROPERTIES, IMAGING...
This method is especially well suited for analyzing time-series data that represent nonstationary and nonlinear physical phenomena. The method is based principally on the concept of empirical mode decomposition (EMD), according to which any complicated signal (as represented by digital samples) can be decomposed into a finite number of functions, called "intrinsic mode functions" (IMFs), that admit well-behaved Hilbert transforms. The local energies and the instantaneous frequencies...
Topics: NASA Technical Reports Server (NTRS), DECOMPOSITION, SPECTRUM ANALYSIS, TIME SERIES ANALYSIS,...
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Jun 2, 2011
06/11
by
Campbell, George S
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Experiments have been made to determine the nature of turbulence in the wake of a two-dimensional airfoil at low speeds. The experiments were motivated by the need for data which can be used for analysis of the tail-buffeting problem in aircraft design. Turbulent intensity and power spectra of the velocity fluctuations were measured at a Reynolds number of 1.6 x 10(exp 5) for several angles of attack. Total-head measurements were also obtained in an attempt to relate steady and fluctuating wake...
Topics: DATA BASES, DATA PROCESSING, DIURNAL VARIATIONS, WINTER, SUMMER, TROPOSPHERE, EXHAUST EMISSION,...
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May 23, 2011
05/11
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Neal, Ralph D.; Weistroffer, H. Roland; Coppins, Richard J
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In order to control the quality of software and the software development process, it is important to understand the measurement of software. A first step toward a better comprehension of software measurement is the categorization of software measures by some meaningful taxonomy. The most worthwhile taxonomy would capture the fundamental nature of the object-oriented (O-O) space. The principal characteristics of object-oriented software offer a starting point for such a categorization of...
Topics: ENERGY BUDGETS, COMBUSTION, BIOMASS, ATMOSPHERIC RADIATION, ADVANCED VERY HIGH RESOLUTION...
An algorithm analyzes rain-gauge data to identify statistical outliers that could be deemed to be erroneous readings. Heretofore, analyses of this type have been performed in burdensome manual procedures that have involved subjective judgements. Sometimes, the analyses have included computational assistance for detecting values falling outside of arbitrary limits. The analyses have been performed without statistically valid knowledge of the spatial and temporal variations of precipitation...
Topics: NASA Technical Reports Server (NTRS), ALGORITHMS, DETECTION, RAIN GAGES, PRECIPITATION MEASUREMENT,...
