SEARCH · Search NASA
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Laser Doppler heterodyning system for velocity measurements without directional ambiguity, employing incident beams of different frequencies through rotating diffraction grating or Bragg cell application
Glancing incidence extreme UV telescopes optical design in solar physics applications, employing surfaces of revolution
Radiative transfer among surfaces forming long cavity exposed to collimated incident energy
Spectral distribution of grating at grazing incidents
Final data analysis of grazing incidence of solar X ray telescope experiment of OSO- 4 satellite
Wind tunnel tests of downwash aerodynamic surface incidence angles on Saturn S-1C booster coupled to Grumman C-4 orbiter shuttle
Pressure distributions and drag coefficients of 18 constant length and volume slender bodies of revolution at zero incidence for Mach numbers 2.0 to 12.0 - graphs
Solar cell performance as function of temperature and illumination angle of incidence
Incident shock wave interaction with liquid hydrocarbon fuel drops in oxidizing and inert atmospheres, considering combustion characteristics and ignition mechanism
Obliquely incident p-polarized plane electromagnetic wave interaction with hot plasma half space, using linearized relativistic Vlasov equation and Laplace transform technique
Fluoride overcoated Al reflectance measurements and polarization effects at various angles of incidence, noting utilization in vacuum UV instrumentation
Kinetic theory of electromagnetic waves obliquely incident upon plasma slab considered as boundary value problem
Simply supported normal mode plate time response to traveling wave at oblique incidence, using numerical analysis
Liquid hydrocarbon fuel drop interaction with incident shock wave in oxidizing and inert atmospheres, investigating aerodynamic shattering and combustion
Spectral measurements of nitrogen continuum radiation behind incident shocks at high speeds, suggesting free bound neutral atom-electron interactions origin
Glancing incidence telescopes of the kind first described by Wolter have now been physically realized, so that it is possible to obtain high-resolution images of celestial objects at all wavelengths greater than about 3 A. The GSFC-MSFC X-ray telescope for the Apollo telescope mount uses Wolter type 1 optics and is capable of forming images of the sun in the 8-70 A region with spatial resolution of the order of one arc second. The GSFC extreme ultraviolet spectroheliometer for OSO H uses type 2 optics and can obtain images of the sun in spectral lines in the 170-400 A region with a spatial resolution of about ten arc seconds. Theoretical (ray trace) and laboratory data on these systems are presented.
The theoretical and practical constraints on designs of grazing-incidence X-ray telescopes are discussed. It is shown that there is a maximum useful diameter for an X-ray telescope. It is further shown that when practical constraints are considered, the maximum reflecting area is not necessarily achieved by utilizing the largest available area within this diameter. Equations are derived that allow rapid calculation of the effective area of an X-ray telescope before one proceeds to detailed studies utilizing Monte Carlo techniques.
The absorption characteristics of several fibrous materials of the Owens Corning 700 Fiberglas Series were measured to determine the variation in impedance as a function of incident angle of the sound wave. The results, indicate that the fibrous absorbents behave as extended reacting materials. The poor agreement between measurement and theory for sound absorption based on the parameters of flow resistance and porosity indicates that this theory does not adequately predict the acoustic behavior of fibrous materials. A much better agreement with measured results is obtained for values calculated from the bulk acoustic parameters of the material.