Planet formation in a triple stellar system: implications of the third star's orbital inclination

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Characterization of a wollastonite glass-ceramic material prepared using sugar cane bagasse ash (SCBA) as one of the raw materials

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Free massive particles with total energy E

We analyze free elementary particles with a rest mass m and total energy Estars, and use Unruh-DeWitt-like detectors to calculate the associated particle detection rate in each case. The (mean) particle position is identified with the spatial average of the excitation probability of the detectors, which are supposed to cover the whole space. Our results are shown to be in harmony with general relativity classical predictions. Eventually we reconcile our conclusions with Earth-based experiments which are in good agreement with E ≥mc2.

Is SAX J1808.4-3658 a Strange Star?

The possibility of strange stars is one of the most important issues in the study of compact objects. Here we use the observations of the newly discovered millisecond x-ray pulsar SAX J1808.4-3658 to constrain the radius of the compact star. Comparing the mass-radius relation of SAX J1808.4-3658 with theoretical models for both neutron stars and strange stars, we argue that a strange star model could be more consistent with SAX J1808.4-3658, and suggest that it is a likely strange star candidate. Our results are useful in constraining microscopic chiral symmetry restoration parameters in the quantum chromodynamics (QCD) modeling of strange matter.

Medium effects in the pion-pole mechanism [gamma gamma ->pi(0)->nu(R)(nu)over-bar(L)(nu(L)(nu)over-bar(R))] of neutron star cooling

Nuclear medium effects in the neutrino cooling of neutron stars through the reaction channel γγ→π0 →ν Rν̄L(νLν̄R) are incorporated. Throughout the paper we discuss different possibilities of right-handed neutrinos, massive left-handed neutrinos, and standard massless left-handed neutrinos (reaction is then allowed only with medium modified vertices). It is demonstrated that multiparticle effects suppress the rate of this reaction channel in the dense hadron matter by 6-7 orders of magnitude that does not allow to decrease existing experimental upper limit on the corresponding π0νν̄ coupling. Other possibilities of the manifestation of the given reaction channel in different physical situations, e.g., in the quark color superconducting cores of the most massive neutron stars, are also discussed. We demonstrate that in the color-flavor-locked superconducting phase for temperatures T≲ 0.1-10 MeV (depending on the effective pion mass and the decay width) the process is feasibly the most efficient neutrino cooling process, although the absolute value of the reaction rate is rather small.

Ácaros de penas (Acari: Astigmata) em aves não passeriformes do Brasil

Pós-graduação em Ciências Biológicas (Zoologia) - IBRC

Influxos do céu na existência dos homens. Os escritos astrológicos na Península Ibérica (séculos XIII, XIV e XV)

Pós-graduação em História - FCHS

Caixa experimentoteca: uma proposta para o ensino de astronomia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Modelos para estimar consumo e exigências nutricionais para poedeiras comerciais

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Produção do monóxido de titânio em estrelas variáveis

Mira are pulsating variable stars in advanced stages of evolution. Their atmospheres are sources of intense absorption bands attributed to molecular titanium monoxide (TiO). It has been suggested that the abundance of TiO reaches its maximum value near the minimum light. In this sense, the study of the processes of formation and destruction of TiO in circumstellar envelopes of Mira stars, not only allows us to understand the physical and chemical processes that occur in these environments, as it allows to verify the correlation between the abundance of TiO and its light curve. However, the main mechanisms of formation and destruction of TiO are poorly known and, consequently, the possible correlation between the abundance of this species and the light curve. In these sense, we studied the main processes of formation and destruction of titanium monoxide in molecular layers of Mira atmospheres and determined its temporal variation as function of the stellar radius. The TiO profile along the radius was expected for the different stellar phase, however its abundance is not enough to explain the light curve. The reasons behind it are discussed in details

Tratamento de um papagaio-verdadeiro (Amazona aestiva) com síndrome do arrancamento de penas usando a técnica de vínculo social e a correção nutricional: relato de caso

The blue-fronted parrot (Amazona aestiva) belongs to the order Psittaciformes and family Pscittacidae. It is widely held as a pet because of its peculiar characteristics. The owners of such animals, however, frequently report behavioral problems. The absence of proper environmental stimuli generated by confinement and lack of social engagement can predispose these animals to characteristic behaviors related to stress, which can be manifested as a feather plucking syndrome. The present study reports the case of a blue-fronted Amazon parrot with a two-year history of feather plucking. The psychosomatic disease was halted once the animal created an emotional bond with a human being. This finding reinforces the social nature of this species and raises questions about the welfare of captive birds of this order.

Perdas na colheita mecanizada de algodão em variabilidade espacial e em função de velocidades de colheita

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relação ideal dos aminoácidos essenciais para mantença, crescimento e produção de aves

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)