9,666 research outputs found
Results of experiments to simulate radiant heating of propellant in a nuclear light bulb engine using a D-C arc radiant energy source
Simulating radiant heating of propellant stream of nuclear light bulb engin
The combined approach to ontology-based data access
The use of ontologies for accessing data is one of
the most exciting new applications of description
logics in databases and other information systems.
A realistic way of realising sufficiently scalable ontology-
based data access in practice is by reduction
to querying relational databases. In this paper,
we describe the combined approach, which incorporates
the information given by the ontology into
the data and employs query rewriting to eliminate
spurious answers. We illustrate this approach for
ontologies given in the DL-Lite family of description
logics and briefly discuss the results obtained
for the EL family
Combined FO rewritability for conjunctive query answering in DL-Lite
Standard description logic (DL) reasoning services such as satisfiability and subsumption mainly aim to support TBox design. When the design stage is over and the TBox is used in an actual application, it is usually combined with instance data stored in an ABox, and therefore query answering becomes the most importan
Dry electrodes for physiological monitoring
Subject preparation and application of sprayed dry electrodes for physiological monitorin
Experimental investigations to simulate the thermal environment, transparent walls, and propellant heating in a nuclear light bulb engine
Simulating thermal environment, transparent walls, and propellant heating in nuclear light bulb engin
GeMs/GSAOI observations of La Serena 94: an old and far open cluster inside the solar circle
Physical properties were derived for the candidate open cluster La Serena 94,
recently unveiled by the VVV collaboration. Thanks to the exquisite angular
resolution provided by GeMS/GSAOI, we could characterize this system in detail,
for the first time, with deep photometry in JHK - bands. Decontaminated
JHK diagrams reach about 5 mag below the cluster turnoff in H. The locus
of red clump giants in the colour - colour diagram, together with an extinction
law, was used to obtain an average extinction of . The
same stars were considered as standard - candles to derive the cluster
distance, kpc. Isochrones were matched to the cluster colour -
magnitude diagrams to determine its age, , and
metallicity, . A core radius of pc was
found by fitting King models to the radial density profile. By adding up the
visible stellar mass to an extrapolated mass function, the cluster mass was
estimated as M, consistent with an
integrated magnitude of and a tidal radius of
pc. The overall characteristics of La Serena 94 confirm that
it is an old open cluster located in the Crux spiral arm towards the fourth
Galactic quadrant and distant kpc from the Galactic centre. The
cluster distorted structure, mass segregation and age indicate that it is a
dynamically evolved stellar system.Comment: 16 pages, 24 figures, 2 Tables, accepted by MNRAS; corrected typo
Low level of virological failure and drug resistance among patients receiving antiretroviral treatment under programme conditions in Maputo, Mozambique
Mexico AIDS Conference 200
Complementary optical-potential analysis of alpha-particle elastic scattering and induced reactions at low energies
A previously derived semi-microscopic analysis based on the Double Folding
Model, for alpha-particle elastic scattering on A~100 nuclei at energies below
32 MeV, is extended to medium mass A ~ 50-120 nuclei and energies from ~13 to
50 MeV. The energy-dependent phenomenological imaginary part for this
semi-microscopic optical model potential was obtained including the dispersive
correction to the microscopic real potential, and used within a concurrent
phenomenological analysis of the same data basis. A regional parameter set for
low-energy alpha-particles entirely based on elastic-scattering data analysis
was also obtained for nuclei within the above-mentioned mass and energy ranges.
Then, an ultimate assessment of (alpha,gamma), (alpha,n) and (alpha,p) reaction
cross sections concerned target nuclei from 45Sc to 118Sn and incident energies
below ~12 MeV. The former diffuseness of the real part of optical potential as
well as the surface imaginary-potential depth have been found responsible for
the actual difficulties in the description of these data, and modified in order
to obtain an optical potential which describe equally well both the low energy
elastic-scattering and induced-reaction data of alpha-particles.Comment: 46 pages, 16 figures. n_TOF Collaboration Annual Meeting, Bari,
Italy, 28-30 November 2007
(http://www.cern.ch/ntof/Documents/bari_nov07/bari_slides.php); revised
version accepted for publication in ADND
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