9,068 research outputs found
From the "high ground" of policy to "the swamp" of professional practice: the challenge of diversity in teaching labour studies
This case study examines the development the diversity management skills of Higher Education students, in the context of the authors' motivation for exploring diversity and an examination of material developed by academics and practitioners from both the United Kingdom and USA. Four elements of the focus course are then presented: student development, learning methods, assessment and student performance. Data from student questionnaires and quotations from students’ reflections on their learning are then analysed. This demonstrates that they can operate with a dual perspective, by both "dissolving differences" and "valuing differences" as an effective means of managing diversity
Candidates for giant lobes projecting from the LBV stars P Cygni and R 143
Deep, wide-field, continuum-subtracted, images in the light of the
Halpha+[NII] 6548 & 6584 A and [O III] 5007 A nebular emission lines have been
obtained of the environment of the Luminous Blue Variable (LBV) star P Cygni. A
previously discovered, receding, nebulous filament along PA 50 deg has now been
shown to extend up to 12' from this star. Furthermore, in the light of [O III]
5007 A, a southern counterpart is discovered as well as irregular filaments on
the opposite side of P Cygni.
Line profiles from this nebulous complex indicate that this extended
nebulosity is similar to that associated with middle-aged supernova remnants.
However, there are several indications that it has originated in P Cygni and is
not just a chance superposition along the same sight-line. This possibility is
explored here and comparison is made with a new image of the LBV star R 143 in
the LMC from which similar filaments appear to project.
The dynamical age of the P Cygni giant lobe of ~5x10^{4} yr is consistent
with both the predicted and observed durations of the LBV phases of 50M stars
after they have left the main sequence. Its irregular shape may have been
determined by the cavity formed in the ambient gas by the energetic wind of the
star, and shaped by a dense torus, when on the main sequence.
The proper motion and radial velocity of P Cygni, with respect to its local
environment, could explain the observed angular and kinematical shifts of the
star compared with the giant lobe.Comment: 7 pages, 3 figures, accepted for publication in A&
The Specific Heat of a Ferromagnetic Film.
We analyze the specific heat for the vector model on a -dimensional
film geometry of thickness using ``environmentally friendly''
renormalization. We consider periodic, Dirichlet and antiperiodic boundary
conditions, deriving expressions for the specific heat and an effective
specific heat exponent, \alpha\ef. In the case of , for , by
matching to the exact exponent of the two dimensional Ising model we capture
the crossover for \xi_L\ra\infty between power law behaviour in the limit
{L\over\xi_L}\ra\infty and logarithmic behaviour in the limit
{L\over\xi_L}\ra0 for fixed , where is the correlation length in
the transverse dimensions.Comment: 21 pages of Plain TeX. Postscript figures available upon request from
[email protected]
The Influence of Thermal Pressure on Equilibrium Models of Hypermassive Neutron Star Merger Remnants
The merger of two neutron stars leaves behind a rapidly spinning hypermassive
object whose survival is believed to depend on the maximum mass supported by
the nuclear equation of state, angular momentum redistribution by
(magneto-)rotational instabilities, and spindown by gravitational waves. The
high temperatures (~5-40 MeV) prevailing in the merger remnant may provide
thermal pressure support that could increase its maximum mass and, thus, its
life on a neutrino-cooling timescale. We investigate the role of thermal
pressure support in hypermassive merger remnants by computing sequences of
spherically-symmetric and axisymmetric uniformly and differentially rotating
equilibrium solutions to the general-relativistic stellar structure equations.
Using a set of finite-temperature nuclear equations of state, we find that hot
maximum-mass critically spinning configurations generally do not support larger
baryonic masses than their cold counterparts. However, subcritically spinning
configurations with mean density of less than a few times nuclear saturation
density yield a significantly thermally enhanced mass. Even without decreasing
the maximum mass, cooling and other forms of energy loss can drive the remnant
to an unstable state. We infer secular instability by identifying approximate
energy turning points in equilibrium sequences of constant baryonic mass
parametrized by maximum density. Energy loss carries the remnant along the
direction of decreasing gravitational mass and higher density until instability
triggers collapse. Since configurations with more thermal pressure support are
less compact and thus begin their evolution at a lower maximum density, they
remain stable for longer periods after merger.Comment: 20 pages, 12 figures. Accepted for publication in Ap
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