59,402 research outputs found
Compressibility effects on fluid entrainment by turbulent mixing layers
Compressibility effects on fluid entrainment by supersonic turbulent mixing layer
Solar-cycle variation of the sound-speed asphericity from GONG and MDI data 1995-2000
We study the variation of the frequency splitting coefficients describing the
solar asphericity in both GONG and MDI data, and use these data to investigate
temporal sound-speed variations as a function of both depth and latitude during
the period from 1995-2000 and a little beyond. The temporal variations in even
splitting coefficients are found to be correlated to the corresponding
component of magnetic flux at the solar surface. We confirm that the
sound-speed variations associated with the surface magnetic field are
superficial. Temporally averaged results show a significant excess in sound
speed around 0.92 solar radii and latitude of 60 degrees.Comment: To be published in MNRAS, accepted July 200
The utilization of neural nets in populating an object-oriented database
Existing NASA supported scientific data bases are usually developed, managed and populated in a tedious, error prone and self-limiting way in terms of what can be described in a relational Data Base Management System (DBMS). The next generation Earth remote sensing platforms (i.e., Earth Observation System, (EOS), will be capable of generating data at a rate of over 300 Mbs per second from a suite of instruments designed for different applications. What is needed is an innovative approach that creates object-oriented databases that segment, characterize, catalog and are manageable in a domain-specific context and whose contents are available interactively and in near-real-time to the user community. Described here is work in progress that utilizes an artificial neural net approach to characterize satellite imagery of undefined objects into high-level data objects. The characterized data is then dynamically allocated to an object-oriented data base where it can be reviewed and assessed by a user. The definition, development, and evolution of the overall data system model are steps in the creation of an application-driven knowledge-based scientific information system
A preliminary look at AVE-SESAME 1 conducted on 10-11 April 1979
Preliminary information on the general weather conditions during the AVE-SESAME 1 period is presented together with a summary of severe weather reports
A Better Definition of the Kilogram
This article reviews several recent proposed redefinitions of the kilogram,
and compares them with respect to practical realizations, uncertainties
(estimated standard deviations), and educational aspects.Comment: 10 pages, no figure
Barrier formation at metal/organic interfaces: dipole formation and the Charge Neutrality Level
The barrier formation for metal/organic semiconductor interfaces is analyzed
within the Induced Density of Interface States (IDIS) model. Using weak
chemisorption theory, we calculate the induced density of states in the organic
energy gap and show that it is high enough to control the barrier formation. We
calculate the Charge Neutrality Levels of several organic molecules (PTCDA,
PTCBI and CBP) and the interface Fermi level for their contact with a Au(111)
surface. We find an excellent agreement with the experimental evidence and
conclude that the barrier formation is due to the charge transfer between the
metal and the states induced in the organic energy gap.Comment: 7 pages, Proceedings of ICFSI-9, Madrid, Spain (September 2003),
special issue of Applied Surface Science (in press
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