1,622 research outputs found
Le phytoplancton estuarien de deux fleuves de Guyane française (l'Iracoubo et le Sinnamary) : caractérisation du milieu, composition et diversité spécifique
Semiclassical Approximation to Neutron Star Superfluidity Corrected for Proximity Effects
The inner crust of a neutron star is a superfluid and inhomogeneous system,
consisting of a lattice of nuclei immersed in a sea of neutrons. We perform a
quantum calculation of the associated pairing gap and compare it to the results
one obtains in the Local Density Approximation (LDA). It is found that the LDA
overestimates the spatial dependence of the gap, and leads to a specific heat
of the system which is too large at low temperatures, as compared with the
quantal result. This is caused by the neglect of proximity effects and the
delocalized character of the single-particle wavefunctions close to the Fermi
energy. It is possible to introduce an alternative, simple semiclassical
approximation of the pairing gap which leads to a specific heat that is in good
agreement with the quantum calculation.Comment: RevteX, 8 Postscript Figure
Tidal Dwarf Galaxies at Intermediate Redshifts
We present the first attempt at measuring the production rate of tidal dwarf
galaxies (TDGs) and estimating their contribution to the overall dwarf
population. Using HST/ACS deep imaging data from GOODS and GEMS surveys in
conjunction with photometric redshifts from COMBO-17 survey, we performed a
morphological analysis for a sample of merging/interacting galaxies in the
Extended Chandra Deep Field South and identified tidal dwarf candidates in the
rest-frame optical bands. We estimated a production rate about 1.4 {\times}
10^{-5} per Gyr per comoving volume for long-lived TDGs with stellar mass 3
{\times} 10^{8-9} solar mass at 0.5<z<1.1. Together with galaxy merger rates
and TDG survival rate from the literature, our results suggest that only a
marginal fraction (less than 10%) of dwarf galaxies in the local universe could
be tidally-originated. TDGs in our sample are on average bluer than their host
galaxies in the optical. Stellar population modelling of optical to
near-infrared spectral energy distributions (SEDs) for two TDGs favors a burst
component with age 400/200 Myr and stellar mass 40%/26% of the total,
indicating that a young stellar population newly formed in TDGs. This is
consistent with the episodic star formation histories found for nearby TDGs.Comment: 9 pages, 5 figures, Accepted for publication in Astrophysics & Space
Scienc
Modelos acoplados do IPCC-AR4 e o gradiente meridional de temperatua da superficie do mar no atlântico tropical : relaçoes com a precipitaçao no norte do nordeste do Brasil
Este artigo mostra como três modelos acoplados do Intergovernmental on Panel Climate Change - (IPCC-AR4), o FGOALS1. 0G – LASG do Institute of Atmospheric Physics of China, o GISSER da National Aeronautics Space Admnistration (NASA) e o GFDL_CM2 da National Oceanic and Atmospheric Administration (NOAA), simularam a variabilidade do gradiente meridional de Temperatura da Superfície do Mar (TSM), entre os meses de fevereiro a maio, no Atlântico Tropical (1901-1999). A precipitação durante a estação chuvosa (fevereiro a maio) no setor norte do Nordeste do Brasil (NEB) foi também analisada pelos três modelos e comparada com as observações. Os modelos GISSER e FGOALS1.0G mostraram melhor desempenho na simulação do sinal do gradiente meridional de TSM no Atlântico Tropical para o período de 1901 a 1999. Destaca-se que os modelos apresentaram um melhor desempenho na simulação da tendência decadal, conseguindo explicar entre 50% a 80% da variabilidade do gradiente, com a TSM do setor sul sendo mais bem simulada
New Upper Limit of Terrestrial Equivalence Principle Test for Rotating Extended Bodies
Improved terrestrial experiment to test the equivalence principle for
rotating extended bodies is presented, and a new upper limit for the violation
of the equivalence principle is obtained at the level of 1.6, which is limited by the friction of the rotating gyroscope. It
means the spin-gravity interaction between the extended bodies has not been
observed at this level.Comment: 4 page
Preferências alimentares e domiciliação de mosquitos Culicidae no Vale do Ribeira, São Paulo, Brasil, com especial referência a Aedes scapularis e a Culex (Melanoconion)
An overview of the current status of CMB observations
In this paper we briefly review the current status of the Cosmic Microwave
Background (CMB) observations, summarising the latest results obtained from CMB
experiments, both in intensity and polarization, and the constraints imposed on
the cosmological parameters. We also present a summary of current and future
CMB experiments, with a special focus on the quest for the CMB B-mode
polarization.Comment: Latest CMB results have been included. References added. To appear in
"Highlights of Spanish Astrophysics V", Proceedings of the VIII Scientific
Meeting of the Spanish Astronomical Society (SEA) held in Santander, 7-11
July, 200
Avaliação da moagem e granulometria do milho e consumo de energia no processamento em moinhos de martelos
Reduction of temporomandibular joint (TMJ) luxation in a horse - case report
ABSTRACT Luxation of the temporomandibular joint (TMJ) in horses, despite being an uncommon condition, is often associated with local trauma involving the head. Its clinical importance is mainly related to the painful injury and impairment of the multiple movements involved in chewing and breaking foods. The objective of the current work is to describe the manual reduction technique of TMJ dislocation in a 6-year-old Mangalarga Marchador stallion with a history of inability to close the oral cavity and lateral displacement of the mandible. In the radiographic and ultrasonographic evaluation of the region a rostral displacement of the mandibular condyle was observed. Manual reduction was effective with the patient under dissociative anesthesia, progressing to medical discharge within 12 days
Charged BTZ-like Black Holes in Higher Dimensions
Motivated by many worthwhile paper about (2 + 1)-dimensional BTZ black holes,
we generalize them to to (n + 1)-dimensional solutions, so called BTZ-like
solutions. We show that the electric field of BTZ-like solutions is the same as
(2 + 1)-dimensional BTZ black holes, and also their lapse functions are
approximately the same, too. By these similarities, it is also interesting to
investigate the geometric and thermodynamics properties of the BTZ-like
solutions. We find that, depending on the metric parameters, the BTZ-like
solutions may be interpreted as black hole solutions with inner (Cauchy) and
outer (event) horizons, an extreme black hole or naked singularity. Then, we
calculate thermodynamics quantities and conserved quantities, and show that
they satisfy the first law of thermodynamics. Finally, we perform a stability
analysis in the canonical ensemble and show that the BTZ-like solutions are
stable in the whole phase space.Comment: 5 pages, two column format, one figur
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