Phase studies of the systems Mn-S, Mn-Se, and MnS-MnSe.
Phase analysis of systems Mn-S, Mn-Se and MnS-MnSe by X ray diffraction techniques, revealing homogeneity ranges
Sigai, A. G.↗
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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Tolerance analysis program
Digital computer program determines tolerance values of end to end signal chain or flow path, given preselected probability value. Technique is useful in the synthesis and analysis phases of subsystem design processes.
Watson, H. K.↗
IUS/TUG orbital operations and mission support study. Volume 3: Space tug operations
A study was conducted to develop space tug operational concepts and baseline operations plan, and to provide cost estimates for space tug operations. Background data and study results are presented along with a transition phase analysis (the transition from interim upper state to tug operations). A summary is given of the tug operational and interface requirements with emphasis on the on-orbit checkout requirements, external interface operational requirements, safety requirements, and system operational interface requirements. Other topics discussed include reference missions baselined for the tug and details for the mission functional flows and timelines derived for the tug mission, tug subsystems, tug on-orbit operations prior to the tug first burn, spacecraft deployment and retrieval by the tug, operations centers, mission planning, potential problem areas, and cost data.
Source record↗
Preliminary results of fisheries investigation associated with Skylab-3
The purpose of the 15-month investigation now in the analysis phase is to establish the feasibility of utilizing remotely sensed data acquired from aircraft and satellite platforms to provide information concerning the distribution and abundance of oceanic gamefish. Data from the test area, jointly acquired by private and professional fishermen and NASA and NOAA/NMFS elements, in the northeastern Gulf of Mexico has made possible the identification of significant environmental parameters for white marlin. Predictive models based on catch data and surface truth information have been developed and have demonstrated potential for reducing search significantly by identifying areas which have a high probability of being productive. Three of the parameters utilized by the model, chlorophyll-a, sea surface temperature and turbidity have been inferred from aircraft sensor data.
Savastano, K.↗
Saturn radio emission near 1 MHz
Radio emissions from the direction of Saturn are analyzed which were observed by IMP-6 at 15 frequencies between 375 and 2200 kHz from April 1971 to October 1972. The radio bursts are identified in the IMP-6 data by a phase analysis of the spin-modulated signal from the spacecraft's dipole antenna, and approximately 12 storms are isolated whose occurrence corresponded to times when the spacecraft had an unobstructed view in the direction of Saturn. The spectral character of the radiation is found to be analogous to that of Jupiter, and a power-spectral analysis of the storm occurrence times indicates a weak periodicity for some of the observing frequencies. The Saturnian emission most similar to Jupiter's decametric emission is found to be strongest at 1100 kHz with a bandwidth of about 1000 kHz. A secondary spectral peak may exist at 400 kHz, which is similar to that observed for Earth and Jupiter. The detection of this nonthermal radio emission is shown to be the first direct evidence for the existence of a Saturnian magnetic field containing energetic particles.
Brown, L. W.↗
Microstructure of hot-pressed Al2O3-Si3N4 mixtures as a function of holding temperature
Powder mixtures of 40 m/o Si3N4-60 m/o Al2O3 were hot-pressed at 4000 psi at various holding temperatures from 1100 C to 1700 C. Scanning Electron Microscopy and Transmission Electro Microscopy results were correlated to X-ray phase analysis and density measurements. The progressively developed microstructure was used to interpret the densification behavior of SiAlON. Photomicrographs of microstructures are shown.
Yeh, H. C.↗
Large Space Telescope - Orbital crew EV maintenance operations
The paper shows that orbital EV maintenance by the crew has a tremendous impact on several areas of the program, including operations, Shuttle interfaces, support equipment rendezvous and berthing, checkout and verification, levels of servicing achievable, logistics and spares and scientific instruments in order to permit changeout and possible future refurbishment. To achieve on-orbit EV maintenance, such challenges as designing for suited-astronaut access to all subsystem equipment elements, minimization for contamination, handling of extremely sensitive instruments, development of translation techniques, and use of existing GFE and hardware must be faced early in the preliminary design and operations analysis phases. All studies to date indicate that on-orbit EV manned maintenance of the LST (Large Space Telescope) is not only feasible but can be designed to be readily within the capability of the EV functioning astronaut. Both 1-g and neutral buoyancy man-in-the-loop simulations further support this point.
Fisher, H. T.↗
Characteristics of the motions, turbulence intensity, diffusivity, flux of momentum and sensible heat in the upper atmosphere
Analyses of the meteorological rocket data obtained from an experiment conducted at 3-hour intervals at 8 western meridional rocket stations are presented. Large variations in the meridional wind contribute substantially to overall turbulence in the tropical stratosphere. The solar semidiurnal component of wind oscillations in the tropics was observed to be much higher than predicted by theory, often exceeding the magnitude of the diurnal amplitude throughout the stratosphere. The observed value of the solar diurnal amplitude in the stratosphere was in line with theoretical prediction. The solar terdiurnal amplitudes for temperature, meridional and zonal winds were non-negligible and must be considered in any harmonic analysis. Phase angle variation with height was rapid for all harmonics; however, there was general agreement between predicted and observed phase angles. Because of large changes in the mean winds in the mesosphere with season, harmonic determinations are difficult. There appear to be large zonal wind changes even within the same season as mentioned previously. Turbulence diffusivity in the upper stratosphere is greater near the equator than in the mid-latitudes.
Kao, S. K.↗
Microstructure of hot-pressed Al2O3-Si3N4 mixtures as a function of holding temperature
Powder mixtures of 40 m/o Si3N4-60 m/o Al2O3 were hot-pressed at 4000 psi at various holding temperatures from 1100 C to 1700 C. Scanning and transmission electron microscopy results were correlated to X-ray phase analysis and density measurements. The progressively developed microstructure was used to interpret the densification behavior of SiAlON.
Yeh, H. C.↗
Meteorological satellites in support of weather modification
During the past several years, many weather modification programs have been incorporating meteorological satellite data into both the operations and the analysis phase of these projects. This has occurred because of the advancement of the satellite as a mesoscale measurement platform, both temporally and spatially, and as the availability of high quality data has increased. This paper surveys the applications of meteorological satellite data to both summer and winter weather modification programs. A description of the types of observations needed by the programs is given, and an assessment of how accurately satellites can determine these necessary parameters is made.
Reynolds, D. W.↗
Characterization and properties of controlled nucleation thermochemical deposited /CNTD/ silicon carbide
Results are presented for an investigation designed to characterize the microstructure of controlled nucleation thermomechanical deposition (CNTD) produced SiC material with respect to grain structure, stoichiometry, phase analysis, etc., and to evaluate the room-temperature and high-temperature fracture and oxidation behavior. By using the CNTD process, ultrafine-grained SiC is deposited on tungsten wires as substrates, with superior surface smoothness and without the macrocolumnar growth commonly observed in conventional CVD materials. The results suggest that the high-purity, fully dense, and stable grain size SiC material produced by CNTD shows potential for high-temperature structural applications, provided that pertinent problems are resolved.
Dutta, S.↗
CF 6 engine diagnostics
A summary of the activities which led to defining deterioration rates of the CF6 family of engines, a description of what was learned, and an identification of means of conserving fuel based upon the program findings are presented. The program to define the deterioration levels and modes for the CF6 family of engines involved four distinct phases: analysis of inbound engine test results, analysis of airline cruise data, analysis of airline test cell data resulting from testing of refurbished engines, and inspection of engine hardware.
Stricklin, R.↗
Spectral variance of aeroacoustic data
An asymptotic technique for estimating the variance of power spectra is applied to aircraft flyover noise data. The results are compared with directly estimated variances and they are in reasonable agreement. The basic time series need not be Gaussian for asymptotic theory to apply. The asymptotic variance formulae can be useful tools both in the design and analysis phase of experiments of this type.
Rao, K. V.↗
Plasma wave experiment for the ISEE-3 mission
Analysis of data from a scientific instrument designed to study solar wind and plasma wave phenomena on the ISEE-3 mission is presented. The performance of work on the data analysis phase is summarized.
Scarf, F. L.↗
Plasma wave experiment for the ISEE-3 mission
An analysis of data from a scientific instrument designed to study solar wind and plasma wave phenomena on the ISEE-3 Mission is provided. Work on the data analysis phase of the contract from 1 October 1982 through 30 March 1983 is summarized.
Scarf, F. L.↗
Orbiter Entry Heating Lessons Learned from Development Flight Test Program
The Space Shuttle orbiter's thermal protection system (TPS), designed mainly on the basis of wind tunnel test data, has successfully completed its design, development, and flight test program. The flight test data provide an exceptional opportunity to evaluate the use of wind tunnel test data for the design of TPS for reentry vehicles. Comparisons of flight test data against wind tunnel data used to design the orbiter's TPS were developed. These flight data, though still in the preliminary analysis phases, generally support the use of wind tunnel test data in the design of TPS for hypersonic reentry vehicles.
Haney, J. W., Jr.↗
Commerce Lab: Mission analysis. Payload integration study
The objectives of the commerce lab mission analysis and payload integration study are discussed. A mission model which accommodates commercial users and provides a basic data base for future mission planning is described. The data bases developed under this study include: (1) user requirements; (2) apparatus capabilities and availabilities; and (3) carrier capabilities. These data bases are synthesized in a trades and analysis phase along with the STS flight opportunities. Optimum missions are identified.
Marvin, G. D.↗
Observations on TeV gamma rays from Geminga and PSR 0950+08
The Geminga (2 CG 195+04) which exhibits a periodicity with a period of 59 to 60 s in its emission of X-rays, GeV gamma rays and TeV gamma rays was studied. During the winter of 1984 to 1985, this object was observed to see if it emits TeV gamma rays with a periodicity approx 60 s. The observations were carried out at two different sites separated by 11 Km with the Ooty Atmospheric Cerenkov Array split into two parts. Data were collected during clear moonless nights for a total duration of 15.3 hours spread over 2 months. Since the first time derivative of period is believed to be large and uncertain. The total data are subdivided into segments of duration not more than 3 days each to steer clear of the effects of P in the phase analysis. If TeV gamma ray signals are seen in each of these segments, it is possible to derive P from observed data.
Bhat, P. N.↗