Integral Fluctuation Relations for Entropy Production at Stopping Times

A stopping time $T$ is the first time when a trajectory of a stochastic process satisfies a specific criterion. In this paper, we use martingale theory to derive the integral fluctuation relation $\langle e^{-S_{\rm tot}(T)}\rangle=1$ for the stochastic entropy production $S_{\rm tot}$ in a stationary physical system at stochastic stopping times $T$. This fluctuation relation implies the law $\langle S_{\rm tot}(T)\rangle\geq 0$, which states that it is not possible to reduce entropy on average, even by stopping a stochastic process at a stopping time, and which we call the second law of thermodynamics at stopping times. This law implies bounds on the average amount of heat and work a system can extract from its environment when stopped at a random time. Furthermore, the integral fluctuation relation implies that certain fluctuations of entropy production are universal or are bounded by universal functions. These universal properties descend from the integral fluctuation relation by selecting appropriate stopping times: for example, when $T$ is a first-passage time for entropy production, then we obtain a bound on the statistics of negative records of entropy production. We illustrate these results on simple models of nonequilibrium systems described by Langevin equations and reveal two interesting phenomena. First, we demonstrate that isothermal mesoscopic systems can extract on average heat from their environment when stopped at a cleverly chosen moment and the second law at stopping times provides a bound on the average extracted heat. Second, we demonstrate that the average efficiency at stopping times of an autonomous stochastic heat engines, such as Feymann's ratchet, can be larger than the Carnot efficiency and the second law of thermodynamics at stopping times provides a bound on the average efficiency at stopping times.Comment: 37 pages, 6 figure

Generic Properties of Stochastic Entropy Production

We derive an Ito stochastic differential equation for entropy production in nonequilibrium Langevin processes. Introducing a random-time transformation, entropy production obeys a one-dimensional drift-diffusion equation, independent of the underlying physical model. This transformation allows us to identify generic properties of entropy production. It also leads to an exact uncertainty equality relating the Fano factor of entropy production and the Fano factor of the random time, which we also generalize to non steady-state conditions.Comment: 5 pages, 5 figures (contains Supplemental Material, 7 pages

In Situ Calibration of Heterogeneous Acquisition Systems: The Monitoring System of a Photovoltaic Plant

This paper deals with the metrological management of an acquisition system that has been developed for monitoring an experimental photovoltaic (PV) plant. The acquisition system has been conceived for comparing the performance of different PV technologies and for verifying the nominal specifications of the PV modules. For these reasons, the traceability of the monitoring system has to be ensured, and therefore, it must be periodically calibrated. A remotely exercised procedure is proposed for the calibration of the acquisition system, which is based on a calibrator specifically designed for this application. This calibrator has the capability to act as a reference for heterogeneous quantities, including electrical quantities, temperature, and solar irradiance. The architecture of this calibrator is described, and experimental results for the preliminary characterization of the prototype are described

Exposure-Tolerant Imaging Solution forCultural Heritage Monitoring

This paper describes a simple and cheap solution specifically designed for monitoring the degradation of thin coatings employed for metal protection. The proposed solution employs a commercial photocamera and a frequency-domain-based approach that is capable of highlighting the surface uniformity changes due to initial corrosion. Even though the proposed solution is specifically designed to monitor the long-time performance of protective coatings employed for the restoration of silver artifacts, it can be successfully used also for assessing the conservation state of other ancient metallic works of art. The proposed solution is made tolerant to exposure changes by using a procedure for sensor nonlinearity identification and correction, does not require a precise lighting control, and employs only free open-source software, so that its overall cost is very low and can be used also by not specifically trained operator

I nodi interpretativi e le possibili soluzioni organizzative per l\u2019attuazione dell\u2019articolo 116, terzo comma, della Costituzione

Nel nostro ordinamento lo slancio per il perseguimento di una trasformazione del sistema regionale \ue8 oggi rappresentato dall\u2019articolo 116, terzo comma, della Costituzione. La sottoscrizione degli Accordi preliminari \u2013 intervenuta nel febbraio del 2018 \u2013 tra il Governo e le Regioni Emilia-Romagna, Lombardia e Veneto, per l\u2019attuazione del c.d. \u201cregionalismo differenziato\u201d, offre l\u2019occasione per riflettere sulle modalit\ue0 procedurali in vista dell\u2019attuazione della disposizione costituzionale in esame. All\u2019interno del testo, passati in rassegna i nodi interpretativi e i problemi attuativi connessi a siffatto processo devolutivo, si propone una soluzione organizzativa per il pi\uf9 ampio coinvolgimento degli organi e delle istituzioni coinvolti.In our system the eagerness for the pursuit of a transformation of the regional system is now embodied by Article 116, third paragraph, of the Constitution. The signing of the preliminary agreements \u2013 which took place in February 2018 \u2013 between the Government and the Emilia-Romagna, Lombardia and Veneto Regions, for the implementation of the \u201cdifferentiated regionalism\u201d, offers the opportunity to discuss the procedural modalities for the implementation of the constitutional provision. This essay moves from the analysis of the interpretative issues and the implementation problems related to the present devolution process, to proposing an organizational solution for the broadest involvement of the bodies and institutions involved in this process

Note minime alla sentenza n. 198 del 2018 della Corte costituzionale: il conflitto tra lo Stato e le regioni sulla nuova disciplina della valutazione di impatto ambientale

The contribution analyzes the sentence n. 198 of 2018 of the Italian Constitutional Court which, by virtue of the claims lodged by some Regions, is pronounced on the constitutional legitimacy of the legislative decree 16 June 2017, n. 104, concerning the revision of the environmental impact assessment framework (EIA). As regard judgment up mentioned, the Italian Constitutional Court asserted that the EIA discipline, regarding the "protection of the environment and the ecosystem", as exclusive legislative matter placed in the hands of the State, contains within it rules capable of affecting transversely the competences of the Regions in order to offer a uniform discipline throughout the national territory. The decision is inserted in the wake of a long and constant constitutional jurisprudence aimed to bringing the discipline of environmental impact assessment back into the category of exclusive competences of the State. At the same time, by virtue of regional complaints, the Court has also the opportunity to address, on the one hand, some aspects concerning the instrument of legislative delegation and,on the other, the constitutional limits belonging to the legislative power of special Regions