Thermodynamics of trajectories of the one-dimensional Ising model

We present a numerical study of the dynamics of the one-dimensional Ising model by applying the large-deviation method to describe ensembles of dynamical trajectories. In this approach trajectories are classified according to a dynamical order parameter and the structure of ensembles of trajectories can be understood from the properties of large-deviation functions, which play the role of dynamical free-energies. We consider both Glauber and Kawasaki dynamics, and also the presence of a magnetic field. For Glauber dynamics in the absence of a field we confirm the analytic predictions of Jack and Sollich about the existence of critical dynamical, or space-time, phase transitions at critical values of the "counting" field $s$. In the presence of a magnetic field the dynamical phase diagram also displays first order transition surfaces. We discuss how these non-equilibrium transitions in the 1$d$ Ising model relate to the equilibrium ones of the 2$d$ Ising model. For Kawasaki dynamics we find a much simple dynamical phase structure, with transitions reminiscent of those seen in kinetically constrained models.Comment: 23 pages, 10 figure

Non-equilibrium Characterization of Spinodal Points using Short Time Dynamics

Though intuitively appealing, the concept of spinodal is rigourously defined only in systems with infinite range interactions (mean field systems). In short-range systems, a pseudo-spinodal can be defined by extrapolation of metastable measurements, but the point itself is not reachable because it lies beyond the metastability limit. In this work we show that a sensible definition of spinodal points can be obtained through the short time dynamical behavior of the system deep inside the metastable phase, by looking for a point where the system shows critical behavior. We show that spinodal points obtained by this method agree both with the thermodynamical spinodal point in mean field systems and with the pseudo-spinodal point obtained by extrapolation of meta-equilibrium behavior in short range systems. With this definition, a practical determination can be achieved without regard for equilibration issues.Comment: 10 pages, 12 figure

Numerical study of the evaporation/condensation phase transition of droplets for an irreversible reaction model

The ZGB model (Zif

The role of extra-corporeal membrane oxygenation (ECMO) in the treatment of diffuse alveolar haemorrhage secondary to ANCA-associated vasculitis : report of two cases and review of the literature

Diffuse alveolar haemorrhage (DAH) secondary to anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) is a rare life-threatening condition presenting with severe respiratory failure. The management of AAV-related DAH consists of remission induction immunosuppressive therapy, which requires time to be effective, with significant fatality rates despite appropriate treatment. Extracorporeal membrane oxygenation (ECMO) can support gas exchanges providing the time necessary for immunosuppressive treatment to control the underlying disease in cases refractory to the conventional ventilation techniques. Despite severe preexisting bleeding has been considered a relative contraindication, ECMO has proven to be life-saving in several cases of respiratory failure associated with pulmonary haemorrhage due to various causes, including AAV. We reviewed the clinical presentation and course of two patients affected by AAV-related DAH treated at our Institution between 2012 and 2017, whose management required the use of veno-venous ECMO. We reviewed the current literature on the role of ECMO in the support of these patients. In both patients, ECMO provided life support and allowed disease control, in combination with immunosuppressive treatment. Despite systemic anticoagulation, clinical improvement was achieved without exacerbation of the pulmonary bleeding. We performed a literature review, and summarized available data confirming the effectiveness and safety of ECMO in AAV-related DAH. ECMO has a life-saving role in the management of patients with severe respiratory failure due to ANCA-associated pulmonary capillaritis