2,161 research outputs found
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Perché traduzione dell'immagine? Perché lo spettatore straniero è in effetti costretto ad operare una traduzione mentale delle immagini che scorrono sullo schermo. Lo spettatore italiano di un film americano non doppiato non vede esattamente un film in versione originale: è costretto, in realtà, a tradurre mentalmente le immagini che percepisce. Noi qui ci occupiamo in particolare del processo traduttivo della colonna sonora. Parlo volutamente di traduzione della colonna sonora perché mi piacerebbe, come professionista del doppiaggio cinetelevisivo, offrire uno spunto di riflessione ai professionisti della ricerca
The Matlab code of the method based on the Full Range Factor for assessing the safety of masonry arches
GRBs and the thermalization process of electron-positron plasmas
We discuss the temporal evolution of the pair plasma created in Gamma-Ray
Burst sources. A particular attention is paid to the relaxation of the plasma
into thermal equilibrium. We also discuss the connection between the dynamics
of expansion and the spatial geometry of the plasma. The role of the baryonic
loading parameter is emphasized.Comment: 4 pages, 3 figures, in the Proceedings of the "Gamma Ray Bursts 2007"
meeting, November 5-9, 2007, Santa Fe, New Mexico, US
Empirical mode decomposition of long-term polar motion observation
We use the Empirical Mode Decomposition (EMD) method to study the decadal variations in polar motion and its long-term trend since year 1900. The existence of the so-called “Markowitz wobble”, a multidecadal fluctuation of the mean pole of rotation whose nature has long been debated since its discovery in 1960, is confirmed. In the EMD approach, the Markowitz wobble naturally arises as an empirical oscillatory term in polar motion, showing significant amplitude variations and a period of approximately 3 decades. The path of the time-averaged, non-cyclic component of polar motion matches the results of previous investigations based on classical spectral methods. However, our analysis also reveals previously unnoticed steep variations (change points) in the rate and the direction of secular polar motion
Anomalous secular sea-level acceleration in the Baltic Sea caused by isostatic adjustment
Observations from the global array of tide gauges show that global sealevel
has been rising at an average rate of 1.5-2 mm/yr during the last
~150 years [Douglas 1991, Spada and Galassi 2012]. Although a global
sea-level acceleration was initially ruled out [Douglas 1992], subsequent
studies [Douglas 1997, Church and White 2006, Jevrejeva et al.
2008, Church and White 2011] have coherently proposed values of ~1
mm/year/century [Olivieri and Spada 2013]. More complex non-linear
trends and abrupt sea-level variations have now also been recognized.
Globally, these could manifest a regime shift between the late Holocene
and the current rhythms of sea-level rise [Gehrels and Woodworth 2013],
while locally they result from ocean circulation anomalies, steric effects
and wind stress [Bromirski et al. 2011, Merrifield 2011]. Although isostatic
readjustment affects the local rates of secular sea-level change
[Milne and Mitrovica 1998, Peltier 2004], a possible impact on regional
acceleration has been so far discounted [Douglas 1992, Jevrejeva et al.
2008, Woodworth et al. 2009] since the process evolves on a millennium
time scale [Turcotte and Schubert 2002]. Here we report a previously unnoticed
anomaly in the long-term sea-level acceleration of the Baltic Sea
tide gauge records, and we explain it by the classical post-glacial rebound
theory and numerical modeling of glacial isostasy. Contrary to previous
assumptions, our findings demonstrate that isostatic compensation plays
a role in the regional secular sea-level acceleration
Quantum dynamics of a high-finesse optical cavity coupled with a thin semi-transparent membrane
We study the quantum dynamics of the cavity optomechanical system formed by a
Fabry-Perot cavity with a thin vibrating membrane at its center. We first
derive the general multimode Hamiltonian describing the radiation pressure
interaction between the cavity modes and the vibrational modes of the membrane.
We then restrict the analysis to the standard case of a single cavity mode
interacting with a single mechanical resonator and we determine to what extent
optical absorption by the membrane hinder reaching a quantum regime for the
cavity-membrane system. We show that membrane absorption does not pose serious
limitations and that one can simultaneously achieve ground state cooling of a
vibrational mode of the membrane and stationary optomechanical entanglement
with state-of-the-art apparatuses.Comment: 14 pages, 7 figure
Quantum dynamics of a vibrational mode of a membrane within an optical cavity
Optomechanical systems are a promising candidate for the implementation of
quantum interfaces for storing and redistributing quantum information. Here we
focus on the case of a high-finesse optical cavity with a thin vibrating
semitransparent membrane in the middle. We show that robust and stationary
optomechanical entanglement could be achieved in the system, even in the
presence of nonnegligible optical absorption in the membrane. We also present
some preliminary experimental data showing radiation-pressure induced optical
bistability.Comment: 6 pages, 2 figures. Work presented at the conference QCMC 2010 held
on 19-23 July 2010 at the University of Queensland, Brisbane, Australi
Efficient algorithms for rigid body integration using optimized splitting methods and exact free rotational motion
Hamiltonian splitting methods are an established technique to derive stable
and accurate integration schemes in molecular dynamics, in which additional
accuracy can be gained using force gradients. For rigid bodies, a tradition
exists in the literature to further split up the kinetic part of the
Hamiltonian, which lowers the accuracy. The goal of this note is to comment on
the best combination of optimized splitting and gradient methods that avoids
splitting the kinetic energy. These schemes are generally applicable, but the
optimal scheme depends on the desired level of accuracy. For simulations of
liquid water it is found that the velocity Verlet scheme is only optimal for
crude simulations with accuracies larger than 1.5%, while surprisingly a
modified Verlet scheme (HOA) is optimal up to accuracies of 0.4% and a fourth
order gradient scheme (GIER4) is optimal for even higher accuracies.Comment: 2 pages, 1 figure. Added clarifying comments. Accepted for
publication in the Journal of Chemical Physic
Switchable Genetic Oscillator Operating in Quasi-Stable Mode
Ring topologies of repressing genes have qualitatively different long-term
dynamics if the number of genes is odd (they oscillate) or even (they exhibit
bistability). However, these attractors may not fully explain the observed
behavior in transient and stochastic environments such as the cell. We show
here that even repressilators possess quasi-stable, travelling-wave periodic
solutions that are reachable, long-lived and robust to parameter changes. These
solutions underlie the sustained oscillations observed in even rings in the
stochastic regime, even if these circuits are expected to behave as switches.
The existence of such solutions can also be exploited for control purposes:
operation of the system around the quasi-stable orbit allows us to turn on and
off the oscillations reliably and on demand. We illustrate these ideas with a
simple protocol based on optical interference that can induce oscillations
robustly both in the stochastic and deterministic regimes.Comment: 24 pages, 5 main figure
Dispersion analysis of the nucleon form factors including meson continua
Dispersion relations provide a powerful tool to analyse the electromagnetic
form factors of the nucleon for all momentum transfers. Constraints from
meson-nucleon scattering data, unitarity, and perturbative QCD can be included
in a straightforward way. In particular, we include the 2pi, rho-pi, and KKbar
continua as independent input in our analysis and provide an error band for our
results. Moreover, we discuss two different methods to include the asymptotic
constraints from perturbative QCD. We simultaneously analyze the world data for
all four form factors in both the space-like and time-like regions and
generally find good agreement with the data. We also extract the nucleon radii
and the omega-NN coupling constants. For the radii, we generally find good
agreement with other determinations with the exception of the electric charge
radius of the proton which comes out smaller. The omega-NN vector coupling
constant is determined relatively well by the fits, but for the tensor coupling
constant even the sign can not be determined.Comment: 24 pages, 9 figure
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