A management of multi-stacks fuel cell systems is proposed to extend systems useful life in a Prognostics and Health Management (PHM) framework. The problem consists in selecting at each time which fuel cell stacks have to run and which output power has to be chosen for each of them to satisfy a load demand as long as possible. Multi-stacks fuel cell system useful life depends not only on each stack useful life, but also on both the schedule and the operating conditions settings that define the contribution of each stack over time. As the impact of variable operating conditions on fuel cell lifetime is not well-known, a simplified representation of fuel cell behavior under wear and tear is used to estimate the available outputs over time and their associated Remaining Useful Lives (RUL). This health state prognostics model is configured to suit to Proton-Exchange Membrane Fuel Cells (PEMFC) specific characteristics. The proposed scheduling process makes use of an optimal approach based on a Mixed Integer Linear Program (MILP). Efficiency of the associated commitment strategy is assessed by comparison with basic intuitive strategies, considering constant and piecewise constant load demand profiles.

"Krokodil" is a home-made opioid drug obtained by synthesizing desomorphine from codeine and combining it with other low-cost additives. Initially introduced in the former Soviet countries, it was then imported to Western Europe as a heroin substitute. To our knowledge, this is the first report of an Italian case of lethal krokodil abuse, that occurred in a 39-year-old man, who died suddenly after transportation to the Emergency Department (ED) for hyperthermia associated with sweating, dyspnoea and tachycardia. Post-mortem examination revealed extensive necrotic ulcerative lesions on the forearms, and autopsy showed a hypertrophic heart with ample endocardial vegetation on the aortic valve and patency of the foramen ovale. Histopathological examination of the heart showed ulcero-vegetative lesions of the aortic valve with an abscess on the annulus and extension to the periaortic adipose tissue, as well as diffuse myocardial interstitial inflammatory neutrophilic infiltrates. Toxicological analysis demonstrated a desomorphine metabolite in urine. On the basis of all these findings the cause of death was ruled to be congestive heart failure caused by endocarditis and myocarditis, correlated with chronic abuse of krokodil.