1,333 research outputs found
High performance astrophysics computing
The application of high end computing to astrophysical problems, mainly in
the galactic environment, is under development since many years at the Dep. of
Physics of Sapienza Univ. of Roma. The main scientific topic is the physics of
self gravitating systems, whose specific subtopics are: i) celestial mechanics
and interplanetary probe transfers in the solar system; ii) dynamics of
globular clusters and of globular cluster systems in their parent galaxies;
iii) nuclear clusters formation and evolution; iv) massive black hole formation
and evolution; v) young star cluster early evolution. In this poster we
describe the software and hardware computational resources available in our
group and how we are developing both software and hardware to reach the
scientific aims above itemized.Comment: 2 pages paper presented at the Conference "Advances in Computational
Astrophysics: methods, tools and outcomes", to be published in the ASP
Conference Series, 2012, vol. 453, R. Capuzzo-Dolcetta, M. Limongi and A.
Tornambe' ed
Cyclic creep and fatigue of TD-NiCr (thoria-dispersion-strengthened nickel-chromium), TD-Ni, and NiCr sheet at 1200 C
The resistance of thin TD-NiCr sheet to cyclic deformation was compared with that of TD-Ni and a conventional nickel-chromium alloy. Strains were determined by a calibration technique which combines room-temperature strain gage and deflection measurements with high-temperature deflection measurements. Analyses of the cyclic tests using measured tensile and creep-rupture data indicated that the TD-NiCr and NiCr alloy specimens failed by a cyclic creep mechanism. The TD-Ni specimens, on the other hand, failed by a fatigue mechanism
Solos do Assentamento Mato Grande - Corumbá, MS: caracterização, limitações e aptidão agrícola.
Argissolos; Cambissolos; Luvissolos; Neossolos; Planossolos; Vertissolos; Aptidão agrícola das terras; Inserção do agricultor no mercado.bitstream/item/37736/1/DOC27.pd
Star cluster disruption by a massive black hole binary
Massive black hole binaries (BHBs) are expected to form as the result of galaxy mergers; they shrink via dynamical friction and stellar scatterings, until gravitational waves (GWs) bring them to the final coalescence. It has been argued that BHBs may stall at a parsec scale and never enter the GW stage if stars are not continuously supplied to the BHB loss cone. Here, we perform several N-body experiments to study the effect of an 8
7 104M 99 stellar cluster (SC) infalling on a parsec-scale BHB. We explore different orbital elements for the SC, and we perform runs both with and without accounting for the influence of a rigid stellar cusp (modelled as a rigid Dehnen potential). We find that the semimajor axis of the BHB shrinks by 73 10 per cent if the SC is on a nearly radial orbit; the shrinking is more efficient when a Dehnen potential is included and the orbital plane of the SC coincides with that of the BHB. In contrast, if the SC orbit has non-zero angular momentum, only few stars enter the BHB loss cone and the resulting BHB shrinking is negligible. Our results indicate that SC disruption might significantly contribute to the shrinking of a parsec-scale BHB only if the SC approaches the BHB on a nearly radial orbit
Adolescent and Young Adult Mental Health is Better in States that Mandate More School Mental Health Policies
Mental health problems and suicide rates have increased among adolescents and young adults over the past several years. This research brief shows that adolescent and young adult mental health is better in states that mandate more school mental health policies, including school-based mental health centers, professional development in suicide prevention, and social-emotional curricula
Solos do Assentamento Urucum - Corumbá, MS: caracterização, limitações e aptidão agrícola.
Cambissolos; Chernossolos; Luvissolos; Neossolos; Vertissolos; Aptidão agrícola das terras; Inserção do agricultor no mercado.bitstream/item/37731/1/DOC30.pd
Adolescent and Young Adult Mental Health is Better in States that Mandate More School Mental Health Policies
Mental health problems and suicide rates have increased among adolescents and young adults over the past several years. This research brief shows that adolescent and young adult mental health is better in states that mandate more school mental health policies, including school-based mental health centers, professional development in suicide prevention, and social-emotional curricula
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