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At least 433 records · Page 24
All sourcesNASA NTRSDOE OSTI
NASA NTRS1971

Data user's note: Mariner 6 and 7 photographic data (NSSDC ID no. 69-014A-01 and 69-030A-01

The availability and assistance in the use of the complete set of Mariner 6 and 7 (1969 14A and 1969 20A) pictorial data are announced. The announcement describes the photographic mission of these Mariner spacecrafts, the television camera system, and the photographs that are available from the National Space Data Center. Two appendixes are included: one is a photographic catalog of all enhanced photographs, designated the maximum discriminability photographs; the other is a series of computer produced graphics that are useful in detailed analysis of the photographs.

Anderson, A. T.↗
NASA NTRS1972

A note on the Gledhill model of the magnetosphere of Jupiter

Free-free emission from a constant density, isothermal rectangular of thickness 2 Jupiter radii and side dimensions 2 x 8 radii is considered. It is determined that the free-free emission from the Gledhill model exceeds the flux measured from the planet over the entire microwave spectrum. Consequently the electron density must be considerably less than Gledhill assumed (10 to the 9th power electrons/cu cm). The upper limit to the electron density which can be set by comparing free-free emission with the observed spectrum is approximately 10 to the 7th power electrons/cu cm.

Gulkis, S.↗
NASA NTRS1972

A note on pole assignment

It is shown that for a controllable, linear time invariant multivariable system at least max (m,p) poles can be assigned arbitrarily. In certain cases more than max (m,p) oikes can be assigned. This result is particularly useful in designing systems for high integrity in the event of transducer failure. In such an event this design takes advantage of the unequal number of inputs and outputs so as to assure no loss in pole assignability.

Sridhar, B.↗
NASA NTRS1972

Note on the origin of Jupiter's magnetic field

The effect of the coriolis force was examined for stability of rotating hydromagnetic systems. It is shown that the effect of this force is to inhibit the onset of instability which leads to convective motion in these systems. The possibility of the existence of a dynamo process in Jupiter's interior is discussed, taking into account the effect of the coriolis force.

Sakurai, K.↗
NASA NTRS1971

A note on the acceleration phase of high-energy particles in the solar flare on 7 July, 1966.

The acceleration phase of solar cosmic rays and relativistic electrons is studied on the basis of the observational data available on the optical, radio, X-ray, and particle events associated with the solar flare that occurred on July 7, 1966. The generating process of hydromagnetic shock waves which excited the type-II radio burst detected at a frequency below about 100 MHz is also discussed. The results of the study suggest that no secondary acceleration process after the explosive phase can contribute much to the generation of high energy particles. The ejection of solar cosmic rays and relativistic electrons seems to be related to the expansion of the magnetic bulge which can trap accelerated electrons from the triggering region of solar flares.

Sakurai, K.↗
NASA NTRS1971

A note on laminar shear flow over impulsively started bodies.

Prediction of the shear flow around bodies impulsively set into motion at a uniform velocity. Information is presented on the local wall shear stress, velocity distribution, steady flow times, and thermal response for wedge flows where local flow acceleration occurs. The essential features of the flow field are found to be describable by the approximate series expansion method of Goldstein and Rosenhead (1936). This method would appear to be useful in rapidly calculating the viscous drag on the forward face of various shaped bodies where local flow acceleration occurs.

Back, L. H.↗
NASA NTRS1971

A note on multiple pure tone noise.

A theoretical investigation of multiple pure tone noise is presented. An analysis based on a two-dimensional inviscid flow model is developed to predict the generation and subsequent evolution of multiple pure tone noise from prescribed blade-to-blade nonuniformities in the rotor geometry. The results show that even small nonuniformities within manufacturing tolerances can be a significant source of multiple pure tone noise. Among the nonuniformities investigated, errors in blade spacing are less significant multiple pure tone noise sources than errors in blade stagger or blade contours.

Kurosaka, M.↗
NASA NTRS1971

A note on chromospheric fine structure at active region polarity boundaries.

High resolution H-alpha filtergrams from Big Bear Solar Observatory reveal that some filamentary features in active regions have fine structure and hence magnetic field transverse to the gross structure and the zero longitudinal field line. These features are distinct from the usual active region filament, in which fine structure, magnetic field, and filament are all parallel to the zero longitudinal field line. The latter occur on boundaries between regions of weaker fields, while the former occur at boundaries between regions of stronger field.

Prata, S. W.↗
NASA NTRS1971

A note on independent variables for restricted three-body problems.

In studies of the elliptic restricted three-body problem, the true anomaly of the motion of the primaries is often used as the independent variable. The equations of motion then show invariancy in form from the circular case. It is of interest whether other independent variables exist, such that the invariant form of the equations is maintained. It is found that true anomaly is the only such variable.

Heppenheimer, T. A.↗
NASA NTRS1972

A note on the calculation of photon loss in an image-tube scanner.

It is found that in the case of 500 image elements and system gains above 3000 only a few per cent of input photons will be lost. Photon loss is not excessive for even lower gains. Aperture variations within a fairly wide range have little effect on the loss. However, losses increase if dead time at the end of a sweep is permitted. A system with continuous sweep at the fastest possible rates is recommended for optimal results.

Mcnall, J. F.↗
NASA NTRS1971

Isoelectronic wavelength calculations for argon spectra /Research note/.

A recent comprehensive set of isoelectronic calculations based on the data of Kelly (1968) has yielded two argon wavelengths that correspond with two of the unidentified wavelengths reported by Connerade et al. (1971) and a third wavelength which supports an uncertain identification. The observed and the interpolated wavelengths are presented in a table together with their identifications, and information concerning the interpolations.

Williams, M. D.↗
NASA NTRS1972

Magnetic fields in umbral atmospheres under 'similarity' configuration /Research note/.

Depth variations in the sunspot magnetic field are studied, and their influence is investigated on the magnetically active line profiles and the resulting magnetographic measurements. An attempt is made to derive a crude, though theoretically sensible magnetic model of a spot, using a simple field configuration conditioned by the 'similarity' law of Schluter and Temesvary (1958). The umbral magnetic field is computed, and the results are presented in tabular form.

Yun, H. S.↗
NASA NTRS1972

A note on mass loss during collisions between galaxies and the formation of giant systems.

Stars will be liberated from the outer portions of galaxies which interact tidally. Using models based on the density distribution observed in the E1 galaxy NGC 3379, the mass loss is computed for hyperbolic collisions on an approximate but conservative basis. Binary collisions are then summed to show that large numbers of stars will be evaporated from elliptical members of dense clusters of galaxies. An estimate of one trillion solar masses is obtained for the amount of material dispersed in the Coma cluster, and in rich very dense systems (Morgan's Type I) the large amount of tidally dispersed debris may constitute the centrally located galaxies designated cD systems which often dominate these clusters.

Gallagher, J. S., III↗
NASA NTRS1972

A note on exponential absolute stability.

A new sufficient condition is formulated for the Lur'e type nonlinear continuous system to be exponentially absolutely stable. The condition relaxes the assumptions on the nonlinear characteristic by modifying the requirements on the linear part of the system.

Siljak, D. D.↗