2,562 research outputs found
Comparing Time Series from Experiments with and without Spiralling
In this paper we compare data from BTA deep-hole drilling experiments conducted according to an experimental design, which had to be repeated due to the development of spiralling in all experiments in the first repetition. We compare the time series of the drilling torque and the bending moment with respect to the development of the maximal Lyapunov-Exponent and the overall relevant frequencies and the relevant frequencies on sections of the process. --
Instanton Solutions for the Universal Hypermultiplet
We expand our previous analysis on fivebrane and membrane instanton solutions
in the universal hypermultiplet, including near-extremal multi-centered
solutions and mixed fivebrane-membrane charged instantons. The results are most
conveniently described in terms of a double-tensor multiplet.Comment: Minor changes, clarification added. Contribution to the proceedings
of the 36th International Symposium Ahrenshoop, August 200
Action for Rehabilitation from Neurological Injury (ARNI): A pragmatic study of functional training for stroke survivors
This article has been made available through the Brunel Open Access Publishing Fund. Copyright @ 2013 Cherry Kilbride et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.This study evaluated the effectiveness of a twelve-week community-based functional training on measures of impairment, activity and participation in a group of stroke survivors. Isometric strength of the knee musculature, Centre-Of-Pressure (COP) based measures of balance, Berg Balance Scale (BBS), 10 m walk test, and the Subjective Index of Physical and Social Out come (SIPSO), were recorded at baseline, post-intervention, and after twelve weeks (follow-up). Exercise instructors delivered training once a week in a group format at a community centre. Significant improvement was noted in the BBS (p < 0.002), and 10 m walk speed (p = 0.03) post intervention which remained unchanged at follow-up. Total SIPSO score improved significantly post-intervention (p = 0.044). No other significant differences and no adverse effects were observed. It is possible that functional training provided more opportunity for the improvement of dynamic aspects of balance control that could be captured by the BBS but not with the traditional measures of balance using COP data. Results also suggest positive effects on the level of participation, and lack of association between measures of impairment and activity. Community based functional training could be effective and used to extend access to rehabilitation services beyond the acute and sub-acute stages after stroke.London Borough of Hillingdo
Disc-protoplanet interaction Influence of circumprimary radiative discs on self-gravitating protoplanetary bodies in binary star systems
Context. More than 60 planets have been discovered so far in systems that
harbour two stars, some of which have binary semi-major axes as small as 20 au.
It is well known that the formation of planets in such systems is strongly
influenced by the stellar components, since the protoplanetary disc and the
particles within are exposed to the gravitational influence of the binary.
However, the question on how self-gravitating protoplanetary bodies affect the
evolution of a radiative, circumprimary disc is still open. Aims. We present
our 2D hydrodynamical GPU-CPU code and study the interaction of several
thousands of self-gravitating particles with a viscous and radiative
circumprimary disc within a binary star system. To our knowledge this program
is the only one at the moment that is capable to handle this many particles and
to calculate their influence on each other and on the disc. Methods. We
performed hydrodynamical simulations of a circumstellar disc assuming the
binary system to be coplanar. Our gridbased staggered mesh code relies on ideas
from ZEUS-2D, where we implemented the FARGO algorithm and an additional energy
equation for the radiative cooling according to opacity tables. To treat
particle motion we used a parallelised version of the precise Bulirsch - Stoer
algorithm. Four models in total where computed taking into account (i) only
N-body interaction, (ii) N-body and disc interaction, (iii) the influence of
computational parameters (especially smoothing) on N-body interaction, and (iv)
the influence of a quiet low-eccentricity disc while running model (ii). The
impact velocities where measured at two different time intervals and were
compared. Results. We show that the combination of disc- and N-body
self-gravity can have a significant influence on the orbit evolution of roughly
Moon sized protoplanets
Physical Processes in Star-Gas Systems
First we present a recently developed 3D chemodynamical code for galaxy
evolution from the K**2 collaboration. It follows the evolution of all
components of a galaxy such as dark matter, stars, molecular clouds and diffuse
interstellar matter (ISM). Dark matter and stars are treated as collisionless
N-body systems. The ISM is numerically described by a smoothed particle
hydrodynamics (SPH) approach for the diffuse (hot) gas and a sticky particle
scheme for the (cool) molecular clouds. Physical processs such as star
formation, stellar death or condensation and evaporation processes of clouds
interacting with the ISM are described locally. An example application of the
model to a star forming dwarf galaxy will be shown for comparison with other
codes. Secondly we will discuss new kinds of exotic chemodynamical processes,
as they occur in dense gas-star systems in galactic nuclei, such as
non-standard ``drag''-force interactions, destructive and gas producing stellar
collisions. Their implementation in 1D dynamical models of galactic nuclei is
presented. Future prospects to generalize these to 3D are work in progress and
will be discussed.Comment: 4 pages, 4 figures, "The 5th Workshop on Galactic Chemodynamics" -
Swinburne University (9-11 July 2003). To be published in the Publications of
the Astronomical Society of Australia in 2004 (B.K. Gibson and D. Kawata,
eds.). Accepted version, minor changes relative to origina
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