We study global non-axisymmetric oscillation modes trapped near the inner boundary of an accretion disc. Observations indicate that some of the quasi-periodic oscillations (QPOs) observed in the luminosities of accreting compact objects (neutron stars, black holes and white dwarfs) are produced in the inner-most regions of accretion discs or boundary layers. Two simple models are considered in ...

Observations of stellar prominences on young rapidly rotating stars provide unique probes of their magnetic fields out to many stellar radii. We compare two independently obtained datasets of the K3 dwarf Speedy Mic (BO Mic, HD 197890) using the Anglo-Australian Telescope (AAT) and the ESO Very Large Telescope (VLT). Taken more than a fortnight apart they provide the first insight into the evol...

We present calculations of magnetic potential functions associated with the perturbation of Saturn’s planetary magnetic field by a rotating, equatorially-situated disc of plasma. Such structures are central to the dynamics of the rapidly rotating magnetospheres of Saturn and Jupiter. They are ‘fed’ internally by sources of plasma from moons such as Enceladus (Saturn) and Io (Jupiter). For these...

  A novel rotating disc electrochemical (RDE) reactor has been developed to treat tannery effluent. Experiments were carried out in batch, batch recirculation, and once-through modes in the reactor covering wide range of operating conditions. The effect of current density (i), cathode rotation speed (R), electrolysis time (t), influent pH, and electrolyte flow rate (Q) on the pollutant removal ...

In my paper " Einstein's ether part A " I mainly reexamined the bucket experiment and earth's daily rotation (the problems that had been occupying Mach and Poincaré) from Einstein's General Relativistic point of view. In this paper I further discuss Einstein's General Relativistic solution to the problems that had been occupying Mach and Poincaré. The disc experiment nstead of Newton's bucket, ...

Results are presented of spectroscopic emission and absorption line observations along the major axis of the Sb galaxy NGC 7331. The kinematics of the ionized gas and stellar component are derived, being regular and symmetric with respect to the centre of the galaxy. Contrary to what may be expected, for R <∼ 40′′ the emission line gas appears to rotate slower than the stars. A likely explanati...

Context. Circumstellar discs are expected to be the nursery of planets. Grain growth within such discs is the first step in the planet formation process. The Bok globule CB 26 harbours such a young disc. Aims. We present a detailed model of the edge-on circumstellar disc and its envelope in the Bok globule CB 26. Methods. The model is based on HST near-infrared maps in the I, J, H, and K bands,...

Making robust predictions for the phase-space distribution of dark matter at the solar neighbourhood is vital for dark matter direct-detection experiments. To date, almost all such predictions have been based on simulations that model the dark matter alone. Here, we use three cosmological hydrodynamic simulations of bright, disc-dominated galaxies to include the effects of baryonic matter self-...

Context. Circumstellar discs are expected to be the nursery of planets. Grain growth within such discs is the first step in the planet formation process. The Bok globule CB 26 harbours such a young disc. Aims. We present a detailed model of the edge-on circumstellar disc and its envelope in the Bok globule CB 26. Methods. The model is based on HST near-infrared maps in the I, J, H, and K bands,...