ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    facet.materialart.
    Unknown
    On presupernova dynamical mass ejection by non-detonated stellar cores (1975)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: Stars in the range of 4 to 8 solar masses are known to develop degenerate carbon-oxygen cores of about 1.4 solar masses. Arguments are presented why, contrary to past assumption, carbon ignition may not lead to the formation of a detonation wave. Rather, an initially subsonic burning front results which subsequently may be brought under control by adiabatic expansion. This dynamic phase leads to a centrally incinerated and expanded core. The loosely bound red-giant envelope is ejected to form an extended nebula. Neutrino cooling of the core finally induces collapse. Provided that sufficient energy is liberated in the dynamic formation of a neutron star, a supernova event will result. The distended nebula is ideally suited for the production of the visible supernova light curves. Thus, carbon nondetonation may give a viable alternative evolution to supernovae that avoids the impasse encountered by the detonation-disrupted models.
    Keywords: ASTROPHYSICS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 2
    facet.materialart.
    Unknown
    Chemical potential effects on neutrino diffusion in supernovae (1975)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: The validity of imposing a zero chemical potential for neutrinos in hydrodynamic calculations of collapsing supernovae is investigated in the diffusion approximation of neutrino transport. A coupled system of equations is solved for neutrino and energy diffusion fluxes as well as lepton diffusion in a collapsing supernovae ambient medium, and the results indicate a substantial growth in the neutrino chemical potential for densities greater than 10 to the 12th power gm/cu cm. The rate of energy transport is shown to be significantly affected by increases in Fermi integrals and chemical-potential gradients accompanied by decreases in temperature, and the extent of neutrino particle/antiparticle reactions is found also to affect energy diffusion rates. It is concluded that the photon-like behavior usually assumed for neutrinos may be incorrect and that an extension of the Sn transport approximation to include lepton characteristics is necessary for a definitive answer to the question of neutrino transport in supernovae.
    Keywords: ASTROPHYSICS
    Type: Astrophysics and Space Science; 35; June 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 3
    facet.materialart.
    Unknown
    Coarse photospheric convection and the ejection of dust by R coronae borealis (1975)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; 198; June 15
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    CAMAC and NIM systems in the space program (1975)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: The CAMAC and NIM instrumentation systems were developed originally to serve the needs of nuclear research institutions in Europe and North America. CAMAC and NIM are currently considered in several studies at the systems level conducted by NASA and ESRO groups. NIM and CAMAC studies for applications related to the space shuttle are discussed along with the advantages provided by aspects of modularization and standardization, a use of NIM and CAMAC equipment in connection with a group of astrophysics experiments, and questions of cost effectiveness.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    Search for X-ray emission from bursting radio sources (1979)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: Results are reported for a systematic search with the A-2 experiment aboard HEAO 1 for X-ray emission from 28 radio sources that were actually bursting at the epoch of the X-ray observations. Two of these sources are found to lie within the positional errors of X-ray sources: the moderately redshifted quasars NRAO 140 and NRAO 530. The positions of 30 historically variable radio sources that were not active at the time of the search are compared with those of detectable X-ray sources, but no X-ray emission is detected from any of these positions. The implications of the results are discussed in terms of models for the radio emission from compact extragalactic sources. Several possible explanations are presented for the general absence of Compton X-ray emission from the bursting radio sources surveyed.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; vol. 233
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 6
    facet.materialart.
    Unknown
    Coordinated photometric and spectroscopic observations of strong extragalactic 90 GHz sources (1978)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: Nearly simultaneous radio and infrared-optical observations were obtained for several extragalactic radio sources which are strong at 90 GHz. The spectral-flux distributions are generally peaked or flat over the radio portion of the spectrum with a steeper, power-law behavior at infrared-optical frequencies. For all sources, the radio and infrared-optical portions of the spectral-flux distributions can be smoothly joined by physically sensible interpolations over the spectral gap, although spectral breaks are required. For many of the sources, this is consistent with a common (synchrotron) origin of the radio, millimeter, and infrared-optical radiation. However, proof, in terms of correlated temporal variations and polarization properties, is still generally lacking.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; vol. 224
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 7
    facet.materialart.
    Unknown
    Pediatrics (1978)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The utilization of the Lixiscope in pediatrics was investigated. The types of images that can presently be obtained are discussed along with the problems encountered. Speculative applications for the Lixiscope are also presented.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: NASA. Goddard Space Flight Center Preliminary Appl. and Evaluation Results. Lixiscope; p 51-59
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 8
    facet.materialart.
    Unknown
    Portable high-resolution laser monochromator-interferometer with multichannel electronic readout (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: A high-resolution 0.4-m monochromator is described for use in wavelength diagnosis of tunable pulsed and CW laser sources in the 3000-10,000-A region. The f/20 design uses an echelle grating in an over-and-under Ebert configuration with a scanned photodiode array to provide a real-time multichannel display of spectral output. Absolute wavelength may be determined to 0.1 A with the monochromator, and a Fabry-Perot interferometer attachment extends linewidth measurement capability to 0.01 A or better. Spectra are displayed on a storage oscilloscope, and calculation of laser parameters is explained. The instrument measures 70 cm long x 15 cm wide x 20 cm high.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: Applied Optics; 18; Dec. 15
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 9
    facet.materialart.
    Unknown
    Pressure Modulator Radiometer (PMR) tests (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The pressure modulator technique was evaluated for monitoring pollutant gases in the Earth's atmosphere of altitude levels corresponding to the mid and lower troposphere. Using an experimental set up and a 110 cm sample cell, pressure modulator output signals resulting from a range of gas concentrations in the sample cell were examined. Then a 20 cm sample cell was modified so that trace gas properties in the atmosphere could be simulated in the laboratory. These gas properties were measured using an infrared sensor.
    Keywords: INSTRUMENTATION AND PHOTOGRAPHY
    Type: NASA-CR-159175
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 10
    facet.materialart.
    Unknown
    Chromospheric emission lines in the red spectrum of AD Leonis. II - Physical conditions in flares (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Keywords: ASTROPHYSICS
    Type: AD-A073306 , AFGL-TR-79-0174 , Astrophysical Journal; vol. 231
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...