313,623 research outputs found
The role of magnetic field for quiescence-outburst models in CVs
In this paper we present the elementary assumptions of our research on the
role of the magnetic field in modelling the quiescence-outbursts cycle in
Cataclysmic Variables (CVs). The behaviour of the magnetic field is crucial not
only to integrate the disk instability model (Osaki 1974), but also to
determine the cause and effect nexus among parameters affecting the behavior of
complex systems. On the ground of our interpretation of the results emerging
from the literature, we suggest that in models describing DNe outbursts, such
as the disk instability model, the secondary instability model (Bath 1973) and
the thermonuclear runaway model (Mitrofanov 1978), the role of the magnetic
field is at least twofold. On the one hand, it activates a specific dynamic
pathway for the accreting matter by channelling it. On the other hand, it could
be indirectly responsible for switching a particular outburst modality. In
order to represent these two roles of the magnetic field, we need to integrate
the disk instability model by looking at the global behaviour of the system
under analysis. Stochastic resonance in dynamo models, we believe, is a
suitable candidate for accomplishing this task. We shall present the MHD model
including this mechanism elsewhere.Comment: 5 pages, 2 figures, CTU Proceedings, Acta Polytechnica (accepted
Wave and Particle Limit for Multiple Barrier Tunneling
The particle approach to one-dimensional potential scattering is applied to
non relativistic tunnelling between two, three and four identical barriers. We
demonstrate as expected that the infinite sum of particle contributions yield
the plane wave results. In particular, the existence of resonance/transparency
for twin tunnelling in the wave limit is immediately obvious. The known
resonances for three and four barriers are also derived. The transition from
the wave limit to the particle limit is exhibit numerically.Comment: 15 pages, 3 figure
The mechanism for the electrooxidation of procarbazine pharmaceutical preparation in alkaline media and its mathematical description
The mechanism for the electrooxidation of procarbazine in alkaline media has been proposed. The process is realized completely on the electrode surface and is adsorption-controlled. The oscillatory behavior in this case is more probable, than for neutral media and may be caused by influences of electrochemical oxidation and salt dissolution from the electrode surface
On the interface polaron formation in organic field-effect transistors
A model describing the low density carrier state in an organic single crystal
FET with high- gate dielectrics is studied. The interplay between
charge carrier coupling with inter-molecular vibrations in the bulk of the
organic material and the long-range interaction induced at the interface with a
polar dielectric is investigated. This interplay is responsible for the
stabilization of a polaronic state with an internal structure extending on few
lattice sites, at much lower coupling strengths than expected from the polar
interaction alone. This effect could give rise to polaron self-trapping in
high- organic FET's without invoking unphysically large values of the
carrier interface interaction.Comment: 9 pages, 9 figure
Bose-Einstein Correlations in e+e- -> W+W- at a Linear Collider
We show that the most popular method to simulate Bose-Einstein (BE)
interference effects predicts negligible correlations between identical pions
originating from the hadronic decay of different W's produced in e+e- -> W+W-
-> 4 jets at typical linear collider energies.Comment: 5 pages, 2 eps figures, Proccedings of the Workshop "Physics Studies
for a Future Linear Collider", QCD Working Group, 2000, DESY 123
Modelling clusters of galaxies by f(R)-gravity
We consider the possibility that masses and gravitational potentials of
galaxy cluster, estimated at X-ray wavelengths, could be explained without
assuming huge amounts of dark matter, but in the context of -gravity.
Specifically, we take into account the weak field limit of such theories and
show that the corrected gravitational potential allows to estimate the total
mass of a sample of 12 clusters of galaxies. Results show that such a
gravitational potential provides a fair fit to the mass of visible matter (i.e.
gas + stars) estimated by X-ray observations, without the need of additional
dark matter while the size of the clusters, as already observed at different
scale for galaxies, strictly depends on the interaction lengths of the
corrections to the Newtonian potential.Comment: 18 pages, 34 figure
Realistic error estimates on kinematic parameters
Current error estimates on kinematic parameters are based on the assumption
that the data points in the spectra follow a Poisson distribution. For
realistic data that have undergone several steps in a reduction process, this
is generally not the case. Neither is the noise distribution independent in
adjacent pixels. Hence, the error estimates on the derived kinematic parameters
will (in most cases) be smaller than the real errors. In this paper we propose
a method that makes a diagnosis of the characteristics of the observed noise
The method also offers the possibility to calculate more realistic error
estimates on kinematic parameters. The method was tested on spectroscopic
observations of NGC3258. In this particular case, the realistic errors are
almost a factor of 2 larger than the errors based on least squares statistics.Comment: 11 pages, 11 figures, accepted for publication by MNRA
Towards a Smarter organization for a Self-servicing Society
Traditional social organizations such as those for the management of
healthcare are the result of designs that matched well with an operational
context considerably different from the one we are experiencing today. The new
context reveals all the fragility of our societies. In this paper, a platform
is introduced by combining social-oriented communities and complex-event
processing concepts: SELFSERV. Its aim is to complement the "old recipes" with
smarter forms of social organization based on the self-service paradigm and by
exploring culture-specific aspects and technological challenges.Comment: Final version of a paper published in the Proceedings of
International Conference on Software Development and Technologies for
Enhancing Accessibility and Fighting Info-exclusion (DSAI'16), special track
on Emergent Technologies for Ambient Assisted Living (ETAAL
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