2,577 research outputs found
NTT infrared imaging of star cluster candidates towards the central parts of the Galaxy
We address the issue whether the central parts of the Galaxy harbour young
clusters other than Arches, Quintuplet and the Nuclear Young Cluster. A large
sample of centrally projected cluster candidates has been recently identified
from the 2MASS J, H and Ks Atlas. We provide a catalogue of higher angular
resolution and deeper images for 57 2MASS cluster candidates, obtained with the
near-IR camera SOFI at the ESO NTT telescope. We classify 10 objects as star
clusters, some of them deeply embedded in gas and/or dust clouds. Three other
objects are probably star clusters, although the presence of dust in the field
does not exclude the possibility of their being field stars seen through
low-absorption regions. Eleven objects are concentrations of stars in areas of
little or no gas, and are classified as dissolving cluster candidates. Finally,
31 objects turned out to be the blend of a few bright stars, not resolved as
such in the low resolution 2MASS images. By combining the above results with
other known objects we provide an updated sample of 42 embedded clusters and
candidates projected within 7 degrees. As a first step we study Object 11 of
Dutra & Bica (2000) projected at approximately 1 degree from the nucleus. We
present H and Ks photometry and study the colour-magnitude diagram and
luminosity function. Object 11 appears to be a less massive cluster than Arches
or Quintuplet, and it is located at a distance from the Sun d=8 kpc, with a
visual absorption Av=15.Comment: accepted to A&A, 9 pages, 10 figure
Remarks on supersymmetry of quantum systems with position-dependent effective masses
We apply the supersymmetry approach to one-dimensional quantum systems with
spatially-dependent mass, by including their ordering ambiguities dependence.
In this way we extend the results recently reported in the literature.
Furthermore, we point out a connection between these systems and others with
constant masses. This is done through convenient transformations in the
coordinates and wavefunctions.Comment: 8 pages, 1 figur
The Challenges of Setting Up a Clinical Study with the New European Union Medical Device Regulation
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Relativistic Mean-Field Hadronic Models under Nuclear Matter Constraints
Relativistic mean-field (RMF) models have been widely used in the study of
many hadronic frameworks because of several important aspects not always
present in nonrelativistic models, such as intrinsic Lorentz covariance,
automatic inclusion of spin, appropriate saturation mechanism for nuclear
matter, causality and, therefore, no problems related to superluminal speed of
sound. With the aim of identifying the models which best satisfy well known
properties of nuclear matter, we have analyzed parameterizations of seven
different types of RMF models under three different sets of constraints related
to symmetric nuclear matter, pure neutron matter, symmetry energy, and its
derivatives. One of these (SET1) is formed of the same constraints used in a
recent work [M. Dutra et al., Phys. Rev. C 85, 035201 (2012)] in which we
analyzed Skyrme parameterizations. The results pointed to models
consistent with all constraints. By using another set of constraints, namely,
SET2a, formed by the updated versions of the previous one, we found models
approved simultaneously. Finally, in the third set, named SET2b, in which the
values of the constraints are more restrictive, we found consistent models.
Another interesting feature of our analysis is that the results change
dramatically if we do not consider the constraint regarding the volume part of
the isospin incompressibility (). In this case, we have
approved models in SET2a and in SET2b.Comment: 63 pages, 3 figures and 9 tables. Version accepted for publication in
PR
Germinação de sementes de leguminosas forrageiras em diferentes condições de estresse salino.
Resumo também publicado em: REUNIÃO ANUAL DA SOCIEDADE BRASILEIRA DE ZOOTECNIA, 37., 2000, Viçosa, MG. Resumos dos trabalhos apresentados. Viçosa, MG: Sociedade Brasileira de Zootecnia, 2000. p. 98
Germinação de sementes de Pueraria phaseoloides: efeitos do pH, do nitrato e da salinidade.
Resumo publicado também em: REUNIÃO ANUAL DA SOCIEDADE BRASILEIRA DE ZOOTECNIA, 36., 1999, Porto Alegre. Resumos dos trabalhos apresentados... Porto Alegre: Sociedade Brasileira de Zootecnia, 1999. p. 105
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