1,565 research outputs found
How an online questionnaire can explore leadership teaching in an undergraduate curriculum.
OBJECTIVES: To design a tool to explore current leadership teaching in an undergraduate curriculum, using the medical leadership competency framework (MLCF)
DESIGN: An online questionnaire was designed based on the MLCF competences and sent to all course leads at Imperial College, London in Autumn 2011
SETTING: Imperial College, London
PARTICIPANTS: Sixty-nine course leads were invited to participate in the questionnaire study
MAIN OUTCOME MEASURES: Course leads were asked whether they teach each MLCF competence, which teaching methods they use, and how long they spend teaching each competency
RESULTS: Overall there was a 78% questionnaire response rate (54/69). From the questionnaires received it was possible to extrapolate results across the remaining courses to achieve a 100% response rate. We were then able to produce a map of current leadership teaching showing that all MLCF competences are taught to varying degrees across the curriculum. The tool does not however provide information on the quality of teaching provided, or what students learn
CONCLUSIONS: There is a strong emphasis on the development of teaching leadership skills to undergraduates in Tomorrow's Doctors 2009 (TD09). It is difficult to know what teaching occurs across the curriculum of a large medical school. The design of a simple, electronic questionnaire will enable medical schools to map their current leadership teaching to the TD09 outcomes. This will help to inform further curriculum development and integration as well as signposting of learning opportunities
The Numerical Simulation of Radiative Shocks I: The elimination of numerical shock instabilities using a localized oscillation filter
We address a numerical instability that arises in the directionally split
computation of hydrodynamic flows when shock fronts are parallel to a grid
plane. Transverse oscillations in pressure, density and temperature are
produced that are exacerbated by thermal instability when cooling is present,
forming post--shock `stripes'. These are orthogonal to the classic post--shock
'ringing' fluctuations. The resulting post--shock `striping' substantially
modifies the flow. We discuss three different methods to resolve this problem.
These include (1) a method based on artificial viscosity; (2) grid--jittering
and (3) a new localized oscillation filter that acts on specific grid cells in
the shock front. These methods are tested using a radiative wall shock problem
with an embedded shear layer. The artificial viscosity method is unsatisfactory
since, while it does reduce post--shock ringing, it does not eliminate the
stripes and the excessive shock broadening renders the calculation of cooling
inaccurate, resulting in an incorrect shock location. Grid--jittering
effectively counteracts striping. However, elsewhere on the grid, the shear
layer is unphysically diffused and this is highlighted in an extreme case. The
oscillation filter method removes stripes and permits other high velocity
gradient regions of the flow to evolve in a physically acceptable manner. It
also has the advantage of only acting on a small fraction of the cells in a two
or three dimensional simulation and does not significantly impair performance.Comment: 20 pages, 6 figures, revised version submitted to ApJ Supplement
Serie
The Centaurus A Northern Middle Lobe as a Buoyant Bubble
We model the northern middle radio lobe of Centaurus A (NGC 5128) as a
buoyant bubble of plasma deposited by an intermittently active jet. The extent
of the rise of the bubble and its morphology imply that the ratio of its
density to that of the surrounding ISM is less than 10^{-2}, consistent with
our knowledge of extragalactic jets and minimal entrainment into the precursor
radio lobe. Using the morphology of the lobe to date the beginning of its rise
through the atmosphere of Centaurus A, we conclude that the bubble has been
rising for approximately 140Myr. This time scale is consistent with that
proposed by Quillen et al. (1993) for the settling of post-merger gas into the
presently observed large scale disk in NGC 5128, suggesting a strong connection
between the delayed re-establishment of radio emission and the merger of NGC
5128 with a small gas-rich galaxy. This suggests a connection, for radio
galaxies in general, between mergers and the delayed onset of radio emission.
In our model, the elongated X-ray emission region discovered by Feigelson et
al. (1981), part of which coincides with the northern middle lobe, is thermal
gas that originates from the ISM below the bubble and that has been uplifted
and compressed. The "large-scale jet" appearing in the radio images of Morganti
et al. (1999) may be the result of the same pressure gradients that cause the
uplift of the thermal gas, acting on much lighter plasma, or may represent a
jet that did not turn off completely when the northern middle lobe started to
buoyantly rise. We propose that the adjacent emission line knots (the "outer
filaments") and star-forming regions result from the disturbance, in particular
the thermal trunk, caused by the bubble moving through the extended atmosphere
of NGC 5128.Comment: 38 pages, 13 figures, submitted to ApJ; a version with higher
resolution figures is available at
http://www.mso.anu.edu.au/~saxton/papers/cena.pd
Space station integrated propulsion and fluid systems study
This Databook addresses the integration of fluid systems of the Space Station program. It includes a catalog of components required for the Space Station elements fluid systems and information on potential hardware commonality. The components catalog is in four parts. The first part lists the components defined for all the fluid systems identified in EP 2.1, Space Station Program Fluid Systems Configuration Databook. The components are cross-referenced in three sections. Section 2.1 lists the components by the fluid system in which they are used. Section 2.2 lists the components by type. Section 2.3 lists by the type of fluid media handled by the component. The next part of the catalog provides a description of the individual component. This section (2.4) is made up of data retrieved from Martin Marietta Denver Aerospace component data base. The third part is an assessment of propulsion hardware technology requirements. Section 2.5 lists components identified during the study as requiring development prior to flight qualification. Finally, Section 2.6 presents the results of the evaluation of commonality between components. The specific requirements of each component have been reviewed and duplication eliminated
Space station integrated propulsion and fluid system study: Fluid systems configuration databook
This databook contains fluid system requirements and system descriptions for Space Station program elements including the United States and International modules, integrated fluid systems, attached payloads, fluid servicers and vehicle accommodation facilities. Separate sections are devoted to each of the program elements and include a discussion of the overall system requirements, specific fluid systems requirements and systems descriptions. The systems descriptions contain configurations, fluid inventory data and component lists. In addition, a list of information sources is referenced at the end of each section
Interactions of Jets with Inhomogeneous Cloudy Media
We present two-dimensional slab-jet simulations of jets in inhomogeneous
media consisting of a tenuous hot medium populated with a small filling factor
by warm, dense clouds. The simulations are relevant to the structure and
dynamics of sources such as Gigahertz Peak Spectrum and Compact Steep Spectrum
radio galaxies, High Redshift Radio Galaxies and radio galaxies in cooling
flows. The jets are disrupted to a degree depending upon the filling factor of
the clouds. With a small filling factor, the jet retains some forward momentum
but also forms a halo or bubble around the source. At larger filling factors
channels are formed in the cloud distribution through which the jet plasma
flows and a hierarchical structure consisting of nested lobes and an outer
enclosing bubble results. We suggest that the CSS quasar 3C48 is an example of
a low filling factor jet - interstellar medium interaction whilst M87 may be an
example of the higher filling factor type of interaction. Jet disruption occurs
primarily as a result of Kelvin-Helmholtz instabilities driven by turbulence in
the radio cocoon not through direct jet-cloud interactions, although there are
some examples of these. In all radio galaxies whose morphology may be the
result of jet interactions with an inhomogeneous interstellar medium we expect
that the dense clouds will be optically observable as a result of radiative
shocks driven by the pressure of the radio cocoon. We also expect that the
radio galaxies will possess faint haloes of radio emitting material well beyond
the observable jet structure.Comment: 21 pages, 16 figures, submitted to MNRAS. A version with full
resolution figures is available at:
http://www.mssl.ucl.ac.uk/~cjs2/pdf/cloudy_hue.pd
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