Patterns of dipole antenna on stratified medium
Radiation patterns of dipole antenna in stratified medium representing lunar surface
Cooper, W. W.↗
SEARCH · Search NASA
Results for “medium”
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.
Discontinuities in the interplanetary medium and their relation to the propagation and acceleration of cosmic rays
Magnetohydrodynamics of discontinuities in interplanetary medium and their relation to propagation and acceleration of cosmic rays
Burlaga, L. F.↗
Very-low frequency electric fields in the interplanetary medium - Pioneer 8
VLF electric field data in interplanetary medium from Pioneer 8 space probe observation
Binsack, J. H.↗
Ogo 5 observations of upstream waves in the interplanetary medium - Discrete wave packets
Upstream discrete wave packets propagation interplanetary medium from Ogo 5 observation
Childers, D. D.↗
Methane-air combustion gases as an aerodynamic test medium
Water vapor condensation effects on methane-air combustion gases for aerodynamic test medium
Howell, R. R.↗
Dispersion relations for guided waves in a simple moving medium
Propagation constant relation to frequency for waveguide filled with simple moving medium, presenting dispersion curves set
Yee, H. Y.↗
Large-amplitude Alfven waves in the interplanetary medium. II
Dynamic nonshock properties of large amplitude microscale Alfven waves in interplanetary medium, using plasma and magnetic field data from Mariner 5
Belcher, J. W.↗
The temperature distribution in an infinite medium resulting from a line source of finite duration
Temperature distribution from line sources and sinks in infinite medium during finite time
Montealegre, A.↗
Signature in the interplanetary medium for substorms
Substorm signature in interplanetary medium relating southward component with solar wind energy transformation
Arnoldy, R. L.↗
Radiofrequency recombination lines from the interstellar medium
Observations of recombination lines form normal H II regions, extended H II regions, nonthermal sources, and the H I medium are discussed. Detection of recombination lines from elements other than hydrogen may provide a means of identifying fossil Stromgren spheres at high temperature.
Dupree, A. K.↗
Wave propagation in a random medium
A simple technique is used to derive statistical characterizations of the perturbations imposed upon a wave (plane, spherical or beamed) propagating through a random medium. The method is essentially physical rather than mathematical, and is probably equivalent to the Rytov method. The limitations of the method are discussed in some detail; in general they are restrictive only for optical paths longer than a few hundred meters, and for paths at the lower microwave frequencies. Situations treated include arbitrary path geometries, finite transmitting and receiving apertures, and anisotropic media. Results include, in addition to the usual statistical quantities, time-lagged functions, mixed functions involving amplitude and phase fluctuations, angle-of-arrival covariances, frequency covariances, and other higher-order quantities.
Lee, R. W.↗
Low intensity H-beta emission from the interstellar medium
Pulsar pulse dispersions and low-frequency absorption of galactic and extragalactic radio sources strongly suggest that the interstellar medium is much more ionized than previously assumed. The search was confined to directions near pulsars because of the additional information provided by the dispersion measure which gives the total number of electrons along the line of sight to the pulsar. Of the four directions in which observations were made, an emission line appears to be present in at least two and possibly three directions. The data are shown from a low galactic latitude direction near the Crab Nebula pulsar. The observing direction was about 9 arcmin off the Crab with the field of view of about 1.5 arcmin. The number of counts was plotted versus the local standard of rest velocity and local standard wavelength of H-beta.
Reynolds, R. J.↗
Energetic solar particles in the interplanetary medium.
Models which describe the diffusion of energetic solar particles in the interplanetary medium are reviewed. Most attention is paid to the case of impulsive emission from solar flares, taking into account the effects of the interplanetary magnetic field, diffusion near the sun, convection, and energy losses associated with the expansion of the solar wind. The case of continuous emission is also considered briefly.
Axford, W. I.↗
Void growth in an elastic-plastic medium.
The uniaxial deformation of an elastic-plastic medium containing a doubly periodic square array of circular cylindrical voids is studied under plane-strain conditions. Both the effects of geometrical nonlinearities resulting from large deformation and physical nonlinearities arising from plastic material behavior are included in formulating the problem. A variational principle is used as the basis for implementing a finite-element solution. Results are obtained for the change in void shape and size under increasing overall strain, the overall tensile behavior of the material with voids, and the development of the plastic zone about a void.
Needleman, A.↗
On the validity of a generalized Kirchhoff's Law for a nonisothermal scattering and absorptive medium.
The relationship of directional hemispherical reflectivity to emissivity is investigated for a nonisothermal medium with isotropic coherent scattering and absorption. Departures from a generalized Kirchhoff's Law occur due to the long range nature of the scattering process. Such departures occur in lunar thermal emission at microwave but not at infrared frequencies.
Linsky, J. L.↗
An improved holographic recording medium
Solid, linear chain hydrocarbons with molecular weight ranging from about 300 to 2000 can serve as long-lived recording medium in optical memory system. Suitable recording hydrocarbons include microcrystalline waxes and low molecular weight polymers or ethylene.
Gange, R. A.↗
Theory of shock waves in a moving medium
The generalization is presented of the known gas dynamic Brinkly-Kirkwood method for the case of plane shock wave propagation in a steady-state moving medium.
Klimishin, I. A.↗
Propagation through a slab of irregularities in a magneto-ionic medium.
A theory is developed to describe the propagation of characteristic waves through an infinite slab of irregularities in a magneto-ionic medium. The theory makes use of the asymptotic Green's dyadic. The results show that mode conversion is possible through scattering from irregularities in an anisotropic background. Some special cases are discussed and an example is given.
Simonich, D. M.↗