Articles
![]() |
06/06/2001--
06/06/2001
Theoretical Considerations of Electrochemical Phase Formation in a Frank-van der Merwe System
Static calculation and preliminary kinetic Monte Carlo simulation studies are
undertaken for the nucleation and growth on a model system which follows a
Frank-van der Merwe mechanism. In the present case, we consider the deposition
of Ag on Au(100) and Au(111) surfaces. The interactions were calculated using
the embedded atom model. The process of formation and growth of 2D Ag
structures on Au(100) and Au(111) is investigated and the influence of surface
steps on this phenomenon is studied. Very different time scales are predicted
for Ag diffusion on Au(100) and Au(111), thus rendering very different regimes
for the nucleation and growth of the related 2D phases. These observations are
drawn from application of a model free of any adjustable parameter.
M. C. Gimenez
M. G. Del Popolo
E. P. M. Leiva
S. G Garcia
D. R. Salinas
C. E. Mayer
W. J. Lorenz
02/03/2003--
02/03/2003
Kinetic Monte Carlo Study of Electrochemical Growth in a Heteroepitaxial System
Structural and kinetic aspects of 2-D irreversible metal deposition under
potentiostatic conditions are analyzed by means of dynamic Monte Carlo
simulations employing embedded atom potentials for a model system. Three
limiting models, all considering adatom diffusion, were employed to describe
adatom deposition.The first model (A) considers adatom deposition on any free
substrate site on the surface at the same rate. The second model (B) considers
adatom deposition only on substrate sites which exhibit no neighboring sites
occupied by adatoms. The third model (C) allows deposition at higher rates on
sites presenting neighboring sites occupied by adatoms.
M. Cecilia Gimenez
Mario G. Del Popolo
Ezequiel P. M. Leiva
06/10/1997--
06/10/1997
Some theoretical considerations concerning ion hydration in the case of ion transfer between water and 1,2-dichloroethane
Some aspects of direct ion transfer across the water/1,2-dichloroethane are
analyzed using a very simple model based on thermodynamic considerations. It
was concluded that ion solvation by water molecules may occur in some
particular cases in the organic phase, delivering an important contribution to
the Gibbs free energy of ion transfer between the aqueous and the organic
phase. In general terms, this particular type of transfer should be favored in
the case of highly charged small ions at interfaces with a relatively low
surface tension and a large difference between the reciprocal of the
corresponding dielectric constants.
C. Sanchez
S. A. Dassie
A. M. Baruzzi
E. P. M. Leiva
09/09/1997--
09/09/1997
Facilitated alkali ion transfer at the water 1,2-dichloroethane interphase: Ab-initio calculations concerning alkaline metal cation - 1,10-phenanthroline complexes
A series of calculations on the energetics of complexation of alkaline metals
with 1,10-phenanthroline are presented. It is an experimental fact that the
ordering of the free energy of transfer across the water - 1,2-dichloroethane
interphase is governed by the charge / size ratio of the diferent cations; the
larger cations showing the lower free energy of transfer. This ordering of the
free energies of transfer is reverted in the presence of 1,10-phenanthroline in
the organic phase. We have devised a thermodynamic cycle for the transfer
process and by means of ab-initio calculations have drawn the conclusion that
in the presence of phen the free energy of transfer is governed by the
stability of the PHEN/M $^{+}$complex, which explains the observed tendency
from a theoretical point of view.
C. Sanchez
S. A. Dassie
A. M. Baruzzi
E. P. M. Leiva
06/26/2019--
06/26/2019
Maximizing LSST Solar System Science: Approaches, Software Tools, and Infrastructure Needs
The Large Synoptic Survey Telescope (LSST) is expected to increase known
small solar system object populations by an order of magnitude or more over the
next decade, enabling a broad array of transformative solar system science
investigations to be performed. In this white paper, we discuss software tools
and infrastructure that we anticipate will be needed to conduct these
investigations and outline possible approaches for implementing them. Feedback
from the community or contributions to future updates of this work are welcome.
Our aim is for this white paper to encourage further consideration of the
software development needs of the LSST solar system science community, and also
to be a call to action for working to meet those needs in advance of the
expected start of the survey in late 2022.
Henry H. Hsieh
Michele T. Bannister
Bryce T. Bolin
Josef Durech
Siegfried Eggl
Wesley C. Fraser
Mikael Granvik
Michael S. P. Kelley
Matthew M. Knight
Rodrigo Leiva
Marco Micheli
Joachim Moeyens
Michael Mommert
Darin Ragozzine
Cristina A. Thomas
12/28/2020--
12/28/2020
Context-Aware Personality Inference in Dyadic Scenarios: Introducing the UDIVA Dataset
This paper introduces UDIVA, a new non-acted dataset of face-to-face dyadic
interactions, where interlocutors perform competitive and collaborative tasks
with different behavior elicitation and cognitive workload. The dataset
consists of 90.5 hours of dyadic interactions among 147 participants
distributed in 188 sessions, recorded using multiple audiovisual and
physiological sensors. Currently, it includes sociodemographic, self- and
peer-reported personality, internal state, and relationship profiling from
participants. As an initial analysis on UDIVA, we propose a transformer-based
method for self-reported personality inference in dyadic scenarios, which uses
audiovisual data and different sources of context from both interlocutors to
regress a target person's personality traits. Preliminary results from an
incremental study show consistent improvements when using all available context
information.
Cristina Palmero
Javier Selva
Sorina Smeureanu
Julio C. S. Jacques Junior
Albert Clapés
Alexa Moseguí
Zejian Zhang
David Gallardo
Georgina Guilera
David Leiva
Sergio Escalera
02/23/2024--
02/23/2024
Artful Path to Healing: Using Machine Learning for Visual Art Recommendation to Prevent and Reduce Post-Intensive Care
Staying in the intensive care unit (ICU) is often traumatic, leading to
post-intensive care syndrome (PICS), which encompasses physical, psychological,
and cognitive impairments. Currently, there are limited interventions available
for PICS. Studies indicate that exposure to visual art may help address the
psychological aspects of PICS and be more effective if it is personalized. We
develop Machine Learning-based Visual Art Recommendation Systems (VA RecSys) to
enable personalized therapeutic visual art experiences for post-ICU patients.
We investigate four state-of-the-art VA RecSys engines, evaluating the
relevance of their recommendations for therapeutic purposes compared to
expert-curated recommendations. We conduct an expert pilot test and a
large-scale user study (n=150) to assess the appropriateness and effectiveness
of these recommendations. Our results suggest all recommendations enhance
temporal affective states. Visual and multimodal VA RecSys engines compare
favourably with expert-curated recommendations, indicating their potential to
support the delivery of personalized art therapy for PICS prevention and
treatment.
Bereket A. Yilma
Chan Mi Kim
Gerald C. Cupchik
Luis A. Leiva
12/09/2002--
12/03/2002
Algebra of chiral currents on the physical surface
Using a particular structure for the Lagrangian action in a one-dimensional
Thirring model and performing the Dirac's procedure, we are able to obtain the
algebra for chiral currents which is entirely defied on the constraint surface
in the corresponding hamiltonian description of the theory.
Alexis Amezaga
Carlos Leiva
02/28/2017--
07/11/2016
Some features of a Schwarzchild Black Hole from a Snyder perspective
In this paper, the consequences of introducing a deformed Snyder-Kepler
potential in the Schwarzchild metric are investigated. After this modification,
it is obtained a dynamically depending horizon with different penetration
radius for massive particles and light rays in radial orbits. In the case of
circular orbits, they all remain untouched.
Carlos Leiva
11/12/2009--
11/12/2009
Mapping the $ν_\odot$ Secular Resonance for Retrograde Irregular Satellites
Constructing dynamical maps from the filtered output of numerical
integrations, we analyze the structure of the $\nu_\odot$ secular resonance for
fictitious irregular satellites in retrograde orbits. This commensurability is
associated to the secular angle $\theta = \varpi - \varpi_\odot$, where
$\varpi$ is the longitude of pericenter of the satellite and $\varpi_\odot$
corresponds to the (fixed) planetocentric orbit of the Sun. Our study is
performed in the restricted three-body problem, where the satellites are
considered as massless particles around a massive planet and perturbed by the
Sun. Depending on the initial conditions, the resonance presents a diversity of
possible resonant modes, including librations of $\theta$ around zero (as found
for Sinope and Pasiphae) or 180 degrees, as well as asymmetric librations (e.g.
Narvi). Symmetric modes are present in all giant planets, although each regime
appears restricted to certain values of the satellite inclination. Asymmetric
solutions, on the other hand, seem absent around Neptune due to its almost
circular heliocentric orbit. Simulating the effects of a smooth orbital
migration on the satellite, we find that the resonance lock is preserved as
long as the induced change in semimajor axis is much slower compared to the
period of the resonant angle (adiabatic limit). However, the librational mode
may vary during the process, switching between symmetric and asymmetric
oscillations. Finally, we present a simple scaling transformation that allows
to estimate the resonant structure around any giant planet from the results
calculated around a single primary mass.
J. Correa Otto
A. M. Leiva
C. A. Giuppone
C. Beaugé
|
|