Classical solutions for D-branes in AdS

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Study of some strategies for disposal of the gnss satellites

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Resonance capture at arbitrary inclination

Resonance capture is studied numerically in the three-body problem for arbitrary inclinations. Massless particles are set to drift from outside the 1: 5 resonance with a Jupiter-mass planet thereby encountering the web of the planet's diverse mean motion resonances. Randomly constructed samples explore parameter space for inclinations from 0 to 180 degrees with 5 degrees increments totalling nearly 6 x 10(5) numerical simulations. 30 resonances internal and external to the planet's location are monitored. We find that retrograde resonances are unexpectedly more efficient at capture than prograde resonances and that resonance order is not necessarily a good indicator of capture efficiency at arbitrary inclination. Capture probability drops significantly at moderate sample eccentricity for initial inclinations in the range [10 degrees,110 degrees]. Orbit inversion is possible for initially circular orbits with inclinations in the range [60 degrees,130 degrees]. Capture in the 1:1 co-orbital resonance occurs with great likelihood at large retrograde inclinations. The planet's orbital eccentricity, if larger than 0.1, reduces the capture probabilities through the action of the eccentric Kozai-Lidov mechanism. A capture asymmetry appears between inner and outer resonances as prograde orbits are preferentially trapped in inner resonances. The relative capture efficiency of retrograde resonance suggests that the dynamical lifetimes of Damocloids and Centaurs on retrograde orbits must be significantly larger than those on prograde orbits implying that the recently identified asteroids in retrograde resonance, 2006 BZ8, 2008 SO218, 2009 QY6 and 1999 LE31 may be among the oldest small bodies that wander between the outer giant planets.

Natural formations at the Earth-Moon triangular point in perturbed restricted problems

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

The evolution of a Pluto-like system during the migration of the ice giants

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

Chaotic Dynamics in a Low-Energy Transfer Strategy to the Equilateral Equilibrium Points in the Earth-Moon System

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

Stable retrograde orbits around the triple system 2001 SN263

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Corrosion resistance of 2024 aluminum alloy coated with plasma deposited a-C:H:Si:O films

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

On nonlinear dynamics and control of a robotic arm with chaos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Deformation and tidal evolution of close-in planets and satellites using a Maxwell viscoelastic rheology

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

Three adult cases of orbital hidrocystoma presenting with blepharoptosis

To report adult cases of superior orbital apocrine hidrocystoma. Retrospective case series of three patients with superior orbital apocrine hidrocystoma and blepharoptosis with review of the clinical aspects of each of the cases. All three cases presented with blepharoptosis. Two of the cases had occult hidrocystoma, and one was visibly subcutaneous at presentation. Although rare and more common along the eyelid margin, apocrine hidrocystomas may occur in the orbit leading to secondary blepharoptosis and should be included within the differential diagnosis of orbital cysts. Physicians should therefore be aware of this possibility.

Dinâmica secular rotacional de corpos tri-axiais: expansão de V em ressonâncias de primeira ordem

Consider a finite body of mass m (C1) with moments of inertia A, B and C. This body orbits another one of mass much larger M (C2), which at first will be taken as a point, even if it is not completely spherical. The body C1, when orbit C2, performs a translational motion near a Keplerian. It will not be a Keplerian due to external disturbances. We will use two axes systems: fixed in the center of mass of C1 and other inertial. The C1 attitude, that is, the dynamic rotation of this body is know if we know how to situate mobile system according to inertial axes system. The strong influence exerted by C2 on C1, which is a flattened body, generates torques on C1, what affects its dynamics of rotation. We will obtain the mathematical formulation of this problem assuming C1 as a planet and C2 as the sun. Also applies to case of satellite and planet. In the case of Mercury-Sun system, the disturbing potential that governs rotation dynamics, for theoretical studies, necessarily have to be developed by powers of the eccentricity. As is known, such expansions are delicate because of the convergence issue. Thus, we intend to make a development until the third order (superior orders are not always achievable because of the volume of terms generated in cases of first-order resonances). By defining a modern set of canonical variables (Andoyer), we will assemble a disturbed Hamiltonian problem. The Andoyer's Variables allow to define averages, which enable us to discard short-term effects. Our results for the resonant angle variation of Mercury are in full agreement with those obtained by D'Hoedt & Lemaître (2004) and Rambaux & Bois (2004)

Estudo de manobras evasivas com perturbações orbitais

Pós-graduação em Física - FEG

Estudos de acoplamento spin-órbita em dinâmica do sistema solar

Pós-graduação em Física - FEG

Aspectos Morfologicos e Histoquimicos de los Musculos Extraoculares del Zorrillo (Didelphis albiventris)

The extraocular muscle fibres of the South-American opossum were determined according to their metabolic profiles using NADH-diaforase, and myofibrilar ATPase after pre-incubation in both acid (pH 4.3) and alkaline (pH 10.4) media. Three muscles were selected to study the arrangement of the fibres (obliquous dorsalis, rectus dorsalis and rectus lateralis muscles). It was demonstrated that they are organized in two layers: the orbital layer composed by small diameter fibres and the global layer with three-times thicker fibres than the former. The global layer has three fibre types: white, red and intermediate; while the orbital layer presents two fibre types, which react differently to the ATPase.