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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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At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1978

Joint infrared and visual monitoring of AM Herculis

Four cycles of the flux from the 3.1 hour X-ray variable AM Her have been observed simultaneously at four wavelengths in the visible and near-infrared. The data show periodic variations at all wavelengths but show systematic changes with wavelength in the relative depths and widths of the primary and secondary minima. The spectral energy distribution varies with phase, being reddest at primary minimum and bluest at the maximum. At primary minimum it is consistent with the energy distribution of an M2 V star plus a component which is flat with frequency; if an M2 V star is present, a lower limit of 100 pc can be placed on the distance to AM Her. The implications of the data on several models for AM Her are discussed.

Priedhorsky, W.↗
NASA NTRS1979

High energy X-ray results from HEAO-1: X-ray pulsars, and the all sky survey

Results of the sky survey performed with the high energy X-ray detectors of the A-4 experiment onboard the HEAO 1 spacecraft are presented. The data presented cover the energy range from 13 to 80 keV. Strong sources are identified by visual inspection and azimuthal superpositions are performed in order to find weak sources. Time variability is also examined. Results of studies of X-ray pulsars are given including a brief description of an X-ray pulsar in terms of current theory.

Levine, A.↗
NASA NTRS1972

Evaluation of nondestructive testing techniques for the space shuttle nonmetallic thermal protection system

A program was conducted to evaluate nondestructive analysis techniques for the detection of defects in rigidized surface insulation (a candidate material for the Space Shuttle thermal protection system). Uncoated, coated, and coated and bonded samples with internal defects (voids, cracks, delaminations, density variations, and moisture content), coating defects (holes, cracks, thickness variations, and loss of adhesion), and bondline defects (voids and unbonds) were inspected by X-ray radiography, acoustic, microwave, high-frequency ultrasonic, beta backscatter, thermal, holographic, and visual techniques. The detectability of each type of defect was determined for each technique (when applicable). A possible relationship between microwave reflection measurements (or X-ray-radiography density measurements) and the tensile strength was established. A possible approach for in-process inspection using a combination of X-ray radiography, acoustic, microwave, and holographic techniques was recommended.

Tiede, D. A.↗
NASA NTRS1974

A new ultrasonic imaging system using time delay spectrometry

A new method of forming a visual image by ultrasound is described. A shadowgraphic transmission image similar to an X-ray radiograph is produced by the application of a technique known as Time Delay Spectrometry. The system uses a repetitive frequency sweep with a linear relationship between frequency and time and the transmitting and receiving crystal are scanned in raster fashion about the subject. By electronic processing, an image may be built up which represents the energy transmitted through the specimen with a given time delay. An intensity modulated picture encompassing the full shades-of-gray capability of the recording system can be produced. A second type of image showing transmission time through the specimen may also be formed. Brightness changes in the displayed image in this case correspond to changes in the ultrasonic transmission time through the specimen.

Heyser, R. C.↗
NASA NTRS1980

Biomedical technology transfer. Applications of NASA science and technology

Ongoing projects described address: (1) intracranial pressure monitoring; (2) versatile portable speech prosthesis; (3) cardiovascular magnetic measurements; (4) improved EMG biotelemetry for pediatrics; (5) ultrasonic kidney stone disintegration; (6) pediatric roentgen densitometry; (7) X-ray spatial frequency multiplexing; (8) mechanical impedance determination of bone strength; (9) visual-to-tactile mobility aid for the blind; (10) Purkinje image eyetracker and stabilized photocoalqulator; (11) neurological applications of NASA-SRI eyetracker; (12) ICU synthesized speech alarm; (13) NANOPHOR: microelectrophoresis instrument; (14) WRISTCOM: tactile communication system for the deaf-blind; (15) medical applications of NASA liquid-circulating garments; and (16) hip prosthesis with biotelemetry. Potential transfer projects include a person-portable versatile speech prosthesis, a critical care transport sytem, a clinical information system for cardiology, a programmable biofeedback orthosis for scoliosis a pediatric long-bone reconstruction, and spinal immobilization apparatus.

Harrison, D. C.↗
NASA NTRS1976

On the distance to the candidate star coincident with A0620-00

High-dispersion echelle spectra of the candidate star for the transient X-ray source A0620-00 are discussed. No absorption or emission lines attributed to the star were found under visual examination of the spectra, but interstellar sodium D lines were clearly visible. Results are presented for measurements of the profiles and central velocities of the sodium absorption lines, and other observations of interstellar features in the general direction of the star are summarized. While the exact distance to the star cannot be determined due to the patchy distribution of the interstellar gas, it is suggested that the star is located between 1.5 and 2.5 kpc; 2 kpc is adopted as the most reasonable value. It is noted that the possibility cannot be ruled out that the star lies beyond 3 kpc and is seen through a hole in the distant neutral hydrogen gas.

Gull, T. R.↗
NASA NTRS1975

Combustion of bulk titanium in oxygen

The combustion of bulk titanium in one atmosphere oxygen is studied using laser ignition and several analytical techniques. These were high-speed color cinematography, time and space resolved spectra in the visible region, metallography (including SEM) of specimens quenched in argon gas, X-ray and chemical product analyses, and a new optical technique, the Hilbert transform method. The cinematographic application of this technique for visualizing phase objects in the combustion zone is described. The results indicate an initial vapor phase reaction immediately adjacent to the molten surface but as the oxygen uptake progresses the evaporation approaches the point of congruency and a much reduced evaporation rate. This and the accumulation of the various soluble oxides soon drive the reaction zone below the surface where gas formation causes boiling and ejection of particles. The buildup of rutile cuts off the oxygen supply and the reaction ceases.

Clark, A. F.↗
NASA NTRS1977

Skylab simulator visual displays and training for joint observing programs

The complexity of the Skylab Apollo Telescope Mount (ATM) experiment operations necessitated the use of high fidelity simulations of the onboard visual displays and pointing system for crew training. The displays which were simulated included the H-alpha displays, XUV monitor display, XUV/slit/white light display, X-ray image display, and the white light coronagraph display. The pointing simulation was achieved by projecting film sequences which were subsequently viewed by TV cameras. An optical system in front of the vidicons simulated the pointing, roll, and zoom capabilities of the ATM and sensing systems. The simulation enabled the Skylab crewmen to obtain valuable integrated training combining such tasks as target recognition and status assessment, complex and the time dependent pointing operations, malfunction analyses, and rapid responses to flare and other transient events.

Holt, A. C.↗
NASA NTRS1974

Search for optical emission from cosmic gamma-ray bursts

Long-exposure films are available for both times and regions of sky for several cosmic gamma-ray bursts. A visual magnitude of no more than 6 was set for optical emission from the well-observed May 14, 1972, event. The corresponding lower limit for the ratio of X-ray to optical energy flux in the burst is greater than 100. This may restrict solar-flare analogy models for the burst sources.

Grindlay, J. E.↗
NASA NTRS1980

Remote sensing data applied to the evaluation of soil erosion caused by land-use. Ribeirao Anhumas Basin Area: A case study

Formerly covered by a tropical forest, the study area was deforested in the early 40's for coffee plantation and cattle raising, which caused intense gully erosion problems. To develop a method to analyze the relationship between land use and soil erosion, visual interpretations of aerial photographs (scale 1:25.000), MSS-LANDSAT imagery (scale 1:250,000), as well as automatic interpretation of computer compatible tapes by IMAGE-100 system were carried out. From visual interpretation the following data were obtained: land use and cover tapes, slope classes, ravine frequency, and a texture sketch map. During field work, soil samples were collected for texture and X-ray analysis. The texture sketch map indicate that the areas with higher slope angles have a higher susceptibilty to the development of gullies. Also, the over carriage of pastureland, together with very friable lithologies (mainly sandstone) occuring in that area, seem to be the main factors influencing the catastrophic extension of ravines in the study site.

Dejesusparada, N.↗
NASA NTRS1976

Infrared emission from A0620-00

Infrared observations of the transient X-ray source A0620-00 were made on Aug. 26 and 29, 1975. When combined with optical data, these observations are consistent with emission from a thermal source which is optically thick at visual wavelengths if the interstellar extinction is about 2.2 magnitudes. Implications of these data for models of the source are discussed.

Kleinmann, S. G.↗
NASA NTRS1979

The orbital period of Algol - 1964 to 1978

A photoelectric observation of minimum light for Algol is reported: JD 2443565.5785 (visual) and JD 2443565.5802 (blue). The times of minima obtained between 1964 and 1978 indicate that a period decrease may have occurred about 1975. It is suggested that this period change, as well as the radio and X-ray activity and spectroscopic anomalies observed during 1975, may have been due to a mass-transfer event that occurred around that time.

Mallama, A. D.↗
NASA NTRS1971

Peripheral venous scintillation angiocardiography in determination of left ventricular volume in man.

Left ventricular end-diastolic volume was determined by cardiac visualization after peripheral venous injection of a gamma-emitting isotope in 10 patients with organic heart disease. The left ventricular end-diastolic volume measured by the isotope method consistently averaged 9% less than that determined by the X-ray method. The mean difference in left ventricular end-diastolic volume was 21 ml. Excellent correlation between the two methods was observed. It is pointed out that peripheral venous scintillation angiocardiography compares well with left ventriculography in the determination of left ventricular end-diastolic volume in man.

Sullivan, R. W.↗
NASA NTRS1980

A bandpass filter for the enhancement of an X-ray reconstruction of the tissue in the spinal canal

In this communication, a new bandpass reconstruction filter is developed to partially remove the low spatial frequencies of the bone and the soft tissue in an X-ray reconstruction of a lumbar spine. This partial removal of the low frequencies suppresses the bony vertebral body and the soft tissue components within the projections of actual clinical data. It also has the effect of enhancing the sharp edges of the fatty tissue surrounding the spinal cord region. The intent of this effort is to directly visualize the spinal cord without the need for water-soluble contrast (e.g., metrizamide) to be installed through lumbar punctures.

Reed, I. S.↗
NASA NTRS1976

Cardiovascular and pulmonary dynamics by quantitative imaging

The accuracy and range of studies on cardiovascular and pulmonary functions can be greatly facilitated if the motions of the underlying organ systems throughout individual cycles can be directly visualized and readily measured with minimum or preferably no effect on these motions. Achievement of this objective requires development of techniques for quantitative noninvasive or minimally invasive dynamic and stop-action imaging of the organ systems. A review of advances in dynamic quantitative imaging of moving organs reveals that the revolutionary value of cross-sectional and three-dimensional images produced by various types of radiant energy such as X-rays and gamma rays, positrons, electrons, protons, light, and ultrasound for clinical diagnostic and biomedical research applications is just beginning to be realized. The fabrication of a clinically useful cross-section reconstruction device with sensing capabilities for both anatomical structural composition and chemical composition may be possible and awaits future development.

Wood, E. H.↗
NASA NTRS1978

Photometry of AM Herculis - A slow optical pulsar

Multicolor photometry of the X-ray binary AM Her suggests that the red component of the optical flux is closely related to the source of optical circular polarization in the system. It is concluded from the periodic modulation of flux in the U through R bands, which is particularly well-defined when plotted as color curves, that the primary and secondary minima are neither eclipses by a secondary star nor eclipses by a hot spot. It is suggested that the primary minimum in the visual light curve is the eclipse of a region of intense optical emission in the magnetic field near the surface of a degenerate dwarf by that dwarf itself.

Priedhorsky, W. C.↗
NASA NTRS1979

The bizarre spectrum of SS 433

Results are reported for extensive spectrophotometric observations, over the wavelength range from 3800 to 7800 A, of the peculiar 14th-mag emission-line object Stephenson-Sanduleak (SS) 433, which has been identified with a variable nonthermal radio source and is positionally coincident with the X-ray source A1909+04. It is found that the spectrum is dominated by intense variable Balmer and He I emission, that three of the He I lines have very prominent P Cygni profiles, and that virtually all the emission features undergo changes in equivalent width on a time scale of days. Anomalous emission features are described which consist of three previously unreported, very strong, broad emission lines at unfamiliar wavelengths in the green, red, and IR, and which vary nightly in intensity, profile, and wavelength. SS 433 is inferred to be a luminous object with an absolute visual magnitude of -3.1 or brighter.

Margon, B.↗