Lindblad Zones: resonant eccentric orbits to aid bar and spiral formation in galaxy discs

Fuzzy Sliding Mode for Spacecraft Formation Control in Eccentric Orbits

The problem of relative motion control for spacecraft formation flying in eccentric orbits is considered in this paper. Due to the presence of nonlinear dynamics and external disturbances, a robust fuzzy sliding mode controller is developed. The slopes of sliding surfaces of the conventional sliding mode controller are tuned according to error states using a fuzzy logic and reach the pre-define...

fuzzy sliding mode for spacecraft formation control in eccentric orbits

the problem of relative motion control for spacecraft formation flying in eccentric orbits is considered in this paper. due to the presence of nonlinear dynamics and external disturbances, a robust fuzzy sliding mode controller is developed. the slopes of sliding surfaces of the conventional sliding mode controller are tuned according to error states using a fuzzy logic and reach the pre-define...

Electromagnetic Formation Flying with Eccentric Reference Orbits

Thin Discs, Thick Discs and Transition Zones

Accretion onto a compact object must occur through a disc when the material has some initial angular momentum. Thin discs and the thicker low radiative efficiency accretion flows (LRAFs) are solutions to this problem that have been widely studied and applied. This is an introduction to these accretion flows within the context of X-ray binaries and cataclysmic variables. Accretion describes the ...

The Bar - enhanced Star - formation Activities in Spiral Galaxies

We use the ratio L FIR /L B and the IRAS color index S 25 /S 12 (both widely used as indices of relative star formation rates in galaxies) to analyse subsets (containing no known AGNs or merging/interacting galaxies) of: (a) the IRAS Bright Galaxy Sample, (b) galaxies from the optically complete RSA sample which have IRAS detections in all four bands, and (c) a volume-limited IR-unselected samp...