1,224 research outputs found
Management control in the transfer pricing tax compliant multinational enterprise
This paper studies the impact of transfer pricing tax compliance on management control system (MCS) design and use within one multinational enterprise (MNE) which employed the same transfer prices for tax compliance and internal management purposes. Our analysis shows immediate effects of tax compliance on the design of organising controls with subsequent effects on planning, evaluating and rewarding controls which reveal a more coercive use of the MCS overall. We argue that modifications to the MCS cannot be understood without an appreciation of the MNEs’ fiscal transfer pricing compliance process
Fluorine production in intermediate-mass stars
The 19F production during the first dozen thermal pulses of AGB stars with
(M=3,Z=0.02), (M=6,Z=0.02) and (M=3,Z=0.001) is investigated on grounds of
detailed stellar models and of revised rates for 15N(a,g)19F and 18O(a,g)22Ne.
These calculations confirm an early expectation that 19F {\it is} produced in
AGB thermal pulses. They also enlarge substantially these previous results by
showing that the variations of the level of 19F production during the evolution
is very sensitive to the maximum temperature reached at the base of the pulse.
These variations are analyzed in detail, and are shown to result from a subtle
balance between different nuclear effects (mainly 19F production or destruction
in a pulse, and 15N synthesis during the interpulse), possibly super-imposed on
dilution effects in more or less extended pulse convective tongues. Our
calculations, as most others, do not predict the third dredge-up self-
consistently. When parametrized, it appears that our models of
intermediate-mass AGB stars are able to account only for the lowest 19F
overabundances observed in solar-metallicity MS, S and C stars. That conclusion
is expected to hold true for low-mass stars when F production results from
secondary 13C only. Massive AGB stars, on the other hand, are not expected to
build up large surface F abundanc- es. Therefore, the large F overabundance
reported for the super Li-rich star WZ Cas (where HBB is supposed to be
operating) remains unexplained so far. Our results for the (M=3,Z=0.001) star
indicate that F surface overabundances can also be expected in low-metallicity
stars provided that third dredge-ups occur after the early cool pulses. The
relative increase in the surface 19F/12C ratio is, however, lower in the
low-metallicity than in the solar-metallicity star. No observations areComment: 27 pages, includes figures, postcript file (A&A format, 15 pages
including figures) can be found via anonymous ftp at
ftp://obsftp.unige.ch/pub/mowlavi/fluor.ps.gz ; accepted by A&
Non-explosive hydrogen and helium burnings: Abundance predictions from the NACRE reaction rate compilation
The abundances of the isotopes of the elements from C to Al produced by the
non-explosive CNO, NeNa and MgAl modes of hydrogen burning, as well as by
helium burning, are calculated with the thermonuclear rates recommended by the
European compilation of reaction rates for astrophysics (NACRE: details about
NACRE may be found at http://astro.ulb.ac.be. This electronic address provides
many data of nuclear astrophysics interest and also offers the possibility of
generating interactively tables of reaction rates for networks and temperature
grids selected by the user). The impact of nuclear physics uncertainties on the
derived abundances is discussed in the framework of a simple parametric
astrophysical model. These calculations have the virtue of being a guide in the
selection of the nuclear uncertainties that have to be duly analyzed in
detailed model stars, particularly in order to perform meaningful
confrontations between abundance observations and predictions. They are also
hoped to help nuclear astrophysicists pinpointing the rate uncertainties that
have to be reduced most urgently.Comment: 13 pages, 13 figures, Latex, accepted for publication in Astronomy
and Astrophysics main journal. Also available at
http://astro.ulb.ac.be/Htm/iaa0.ht
A CORAVEL radial-velocity monitoring of giant Ba and S stars: spectroscopic orbits and intrinsic variations
This paper provides orbital parameters for 38 barium stars and 10 extrinsic S
stars derived from a decade-long CORAVEL monitoring. Lower bounds on the
orbital period (generally exceeding 10 y) have been obtained for 10 more
systems. Mira S, SC and (Tc-poor) C stars have also been monitored and show
intrinsic radial-velocity variations due to atmospheric phenomena. Tentative
orbital solutions are proposed for 3 stars (S UMa, X Cnc, BD-08:1900) where the
velocity and photometric periods are different. Three stars (RZ Peg, SS Vir and
R CMi) exhibit radial-velocity variations synchronous with the light
variations. Pseudo-orbital solutions have been derived for those stars. In the
case of RZ Peg, a line-doubling phenomenon is observed near maximum light, and
probably reflects the shock wave propagating through the photosphere.Comment: Astronomy & Astrophysics Supplements, 20 pages, 8 figures, 8 tables
(LaTeX). Also available at:
http://obswww.unige.ch/~udry/cine/barium/barium.htm
A CORAVEL radial-velocity monitoring of S stars: symbiotic activity vs. orbital separation
Orbital elements are presented for the Tc-poor S stars HR 363 (= HD 7351) and
HD 191226. With an orbital period of 4592 d (=12.6 y), HR 363 has the longest
period known among S stars, and yet it is a strong X-ray source. Its X-ray flux
is similar to that of HD 35155, an S star with one of the shortest orbital
periods (640 d). This surprising result is put in perspective with other
diagnostics of binary interaction observed in binary S stars. They reveal that
there is no correlation between the level of binary interaction and the orbital
period. This situation may be accounted for if the wind mass-loss rate from the
giant is the principal factor controlling the activity level in these
(detached) systems, via a stream of matter funneled through the inner Lagragian
point.Comment: Astronomy & Astrophysics Supplements, 6 pages, 2 figures, 4 tables
(LaTeX A&A). Also available at:
http://obswww.unige.ch/~udry/cine/barium/barium.htm
Dynamical streams in the solar neighbourhood
The true nature of the Hyades and Sirius superclusters is still an open
question. In this contribution, we confront Eggen's hypothesis that they are
cluster remnants with the results of a kinematic analysis of more than 6000 K
and M giants in the solar neighbourhood. This analysis includes new radial
velocity data from a large survey performed with the Coravel spectrometer,
complemented by Hipparcos parallaxes and Tycho-2 proper motions (Famaey et al.
2004). A maximum-likelihood method, based on a bayesian approach, has been
applied to the data, in order to make full use of all the available data
(including less precise parallaxes) and to derive the properties of the
different kinematic subgroups. Two such subgroups can be identified with the
Hyades and Sirius superclusters. Stars belonging to them span a very wide range
of age, which is difficult to account for in Eggen's scenario. These groups are
thus most probably "dynamical streams" related to the dynamical perturbation by
spiral waves rather than to cluster remnants.
In this scenario, the Hyades and Ursa Major clusters just happen to be in the
Hyades and Sirius streams, which are purely dynamical features that have
nothing to do with the remnants of more massive primordial clusters. This
mechanism could be the key to understanding the presence of an old metal-rich
population, and of many exoplanetary systems in our neighbourhood. Moreover, a
strong spiral pattern seems to be needed in order to yield such prominent
streams. Since spiral structure is usually baryonic, this would leave very
little room for dark matter. This may be an indication that the era of the
dark-matter paradigm explaining the dynamics of the Galaxy may come to an end,
and is being superseded by modified gravity.Comment: 5 pages, 1 figure, to appear in The Three Dimensional Universe with
GAIA, eds M. Perryman & C. Turo
The Abundance of Interstellar Fluorine and Its Implications
We report results from a survey of neutral fluorine (F I) in the interstellar
medium. Data from the Far Ultraviolet Spectroscopic Explorer (FUSE) were used
to analyze 26 lines of sight lying both in the galactic disk and halo,
including lines to Wolf-Rayet stars and through known supernova remnants. The
equivalent widths of fluorine resonance lines at 951.871 A and 954.827 A were
measured or assigned upper limits and combined with a nitrogen curve of growth
to obtain F I column densities. These column densities were then used to
calculate fluorine depletions. Comparisons are made to the previous study of F
I by Federman et al. (2005) and implications for F I formation and depletion
are discussed.Comment: 32 pages, 10 figures, Accepted to Ap
Fluorine abundances in planetary nebulae
We have determined fluorine abundances from the F II 4789 and F IV 4060
nebular emission lines for a sample of planetary nebulae (PNe). Our results
show that fluorine is generally overabundant in PNe, thus providing new
evidence for the synthesis of fluorine in asymptotic giant branch (AGB) stars.
[F/O] is found to be positively correlated with the C/O abundance ratio, in
agreement with the predictions of theoretical models of fluorine production in
thermally pulsing AGB stars. A large enhancement of fluorine is observed in the
Wolf-Rayet PN NGC 40, suggesting that high mass-loss rates probably favor the
survival of fluorine.Comment: 4 pages, 3 figures, accepted for publication in ApJ Letter
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