25 research outputs found
Sum of exit times in series of metastable states in probabilistic cellular automata
Reversible Probabilistic Cellular Automata are a special class
of automata whose stationary behavior is described by Gibbs--like
measures. For those models the dynamics can be trapped for a very
long time in states which are very different from the ones typical
of stationarity.
This phenomenon can be recasted in the framework of metastability
theory which is typical of Statistical Mechanics.
In this paper we consider a model presenting two not degenerate in
energy
metastable states which form a series, in the sense that,
when the dynamics is started at one of them, before reaching
stationarity, the system must necessarily visit the second one.
We discuss a rule for combining the exit times
from each of the metastable states
Sum of exit times in series of metastable states in Probabilistic Cellular Automata
Reversible Probabilistic Cellular Automata are a special class of automata whose stationary behavior is described by Gibbs-like measures. For those models the dynamics can be trapped for a very long time in states which are very different from the ones typical of stationarity. This phenomenon can be recasted in the framework of metastability theory which is typical of Statistical Mechanics. In this paper we consider a model presenting two not degenerate in energy metastable states which form a series, in the sense that, when the dynamics is started at one of them, before reaching stationarity, the system must necessarily visit the second one. We discuss a rule for combining the exit times from each of the metastable states
High reflectivity Bragg reflectors based on a gold nanoparticle/Teflon-like composite material as a new approach to organic solvent detection
We report on the properties of a new optical sensing element for organic solvents based on polymeric distributed Bragg reflector (DBR), which can be easily interfaced with optical fibers. The DBR is a periodic stack of alternating Teflon-like and gold nanoparticle/Teflon-like composite layers showing high reflectivity in the optical telecommunication spectral range and sensing proper-ties due to the peculiar absorbing properties of the composite layers. The swelling of the composite layers in presence of organic vapors causes a DBR periodicity change and this results in the shift of the high reflectivity window. (C) 2004 Elsevier B.V. All rights reserved
A new approach to organic solvent detection: High-reflectivity Bragg reflectors based on a gold nanoparticle/teflon-like composite material
A new sensing element for organic solvents based on a polymeric distributed Bragg reflector (DBR) is presented. The periodic stack consists of alternating Teflon-like and gold nanoparticle/Teflon-like layers, and shows high reflectivity in the optical telecommunications spectral range. Sensing properties are due to the peculiar absorbing behavior of composite layers, which swell in the presence of organic vapors, causing DBR periodicity change and consequently the high reflectivity window shift (see Figure)
Threshold effects in zero range processes
We study a zero range process characterized by the presence of a threshold switching the particle dynamics from the independent particle model to the simple exclusion process. The setting is relevant to pedestrian dynamics in obscured corridors. We investigate the hydrodynamic limit of the model considering both symmetric and asymmetric jump probabilities, and highlight the effect of the threshold parameter on the resulting behavior of the diffusion coefficient and of the outgoing current
Sum of exit times in series of metastable states in probabilistic cellular automata
\u3cp\u3eReversible Probabilistic Cellular Automata are a special class of automata whose stationary behavior is described by Gibbs-like measures. For those models the dynamics can be trapped for a very long time in states which are very different from the ones typical of stationarity. This phenomenon can be recasted in the framework of metastability theory which is typical of Statistical Mechanics. In this paper we consider a model presenting two not degenerate in energy metastable states which form a series, in the sense that, when the dynamics is started at one of them, before reaching stationarity, the system must necessarily visit the second one. We discuss a rule for combining the exit times from each of the metastable states.\u3c/p\u3